Database Overview

The DASCH project data is currently organized in three MySQL databases: the scanner database, the photometry database, and the auxscanner database. The scanner database contains the logbook information and keeps track of the scanning and processing of plates. The photometry database stores the results of the photometry pipeline, which is implemented using Starbase Data Tables, and enables lightcurve plotting and statistical analysis of the photometry data. The auxscanner database contains miscellaneous secondary data derived from other tables and files to improve overall processing performance.

Scanner Database

The scanner database contains the following tables for management of the scanning process, support of the photometry pipeline, and support of this website.

global	Contains global constants, control variables, and a time stamp.
locations	Contains observatory latitudes, longitudes, and elevations.
ranges	Associates plate series numbers with observatory locations and the expected time type (UT, EST, SAST,...) . Handles duplicate plate numbers.
series	Contains a list all of the telescopes and their characteristics
classes	Contains a lists all known plate classes
plates	Contains a list of all known plates. Contains a record of low resolution photographs of the plates and the plate jackets. Contains an overall plate quality flag.
exposures	Contains a list of all exposures and their characteristics as derived from the logbooks
catalog	Contains transcriptions of the plate stacks card catalog. This data is being replaced by more detailed data from the logbooks themselves.
logbook	Contains transcriptions of logbook data
logranges	Contains the ranges of plate numbers in each logbook volume. This table is used in the verification of logbook transcriptions.
platerename	Contains a table of renamed plates (deprecated)
scanPatterns	Contains a table of plate scan patterns executed by the digitizer.
scanLocations	Contains a table of individual scan tile patterns for each scan pattern in the scanPatterns table
scans	Contains a table of all plate scans executed by the digitizer
mosaics	Contains a table of all mosaics generated from digitizer plate scans. This table contains World Coordinate Systems coefficients of each plate for the automated searches implemented by this website.
fithistory	Contains a record of WCS fitting attempts (deprecated)
astromfithistory	Contains the history of WCS fitting attempts after the transition to astrometry.net

Photometry Database

The database replaces a collection of Starbase Data Tables generated by the photometry pipeline. The intent of the photometry database is to provide rapid access to any lightcurve in the DASCH database. As currently designed, the photometry database contains the tables listed below. The primary spatial index into the database is a gsc_bin_index which divides the sky into 168,966,386 bins of height 1/64 degree in declination and approximately 1/64 degree in right ascension. This index is similar to the hierarchical triangle index developed for the SDSS, but optimized for rapid raster searches of the GSC2.3.2 star catalog. The illustration on the left shows how the tables are used to generate lightcurves.

photglobal	Contains global constants, control variables, and a time stamp.
photversions	Contains version strings and identifiers in recognition of continuing development of the photometry pipeline. The versions are used to recognize and purge stale data from the other tables.
photseries	Contains a copy of the series table index from the scanner database for more efficient MySQL queries
stars	Contains the star index based on either location or GSC2.3.2 reference ID and the GSC2.3.2 magnitude and color.
stars1	Contains the star index based on either location or Kepler Input Catalog reference ID and the Kepler Input Catalog magnitude and color.
stars2	Contains the star index based on either location or APASS Catalog reference ID and APASS magnitude and color.
photplates	Contains a list of all plates processed by the photometry pipeline and global plate parameters, such as the plate scale, mosaic size, and Sextractor THRESHOLD level.
spatialbin	Contains derived parameters for the nine annular bins for each plate analyzed. These parameters include number of stars analyzed, limiting magnitude, upper limits, colorterm values, and bin rms.
localbin	Contains derived parameters for the 50x50 grid of local correction bins for each plate analyzed. These parameters include altitude in the sky; plate extinction; local calibration correction, number of stars, and correction rms value; and astrometry error measurements.
magnitudes	Contains values for each image on the plates. These values include GSC2.3.2 reference ID, plate coordinates, processing flags, magnitude, magnitude error, Heliocentric Julian date, and Sextractor shape parameters. This table is too large for efficient processing by MySQL and now consists of a series of binary files indexed by the gsc_bin_index.
starsummary	Contains lightcurve statistics such as the number of points, DASCH magnitude and rms, clipped DASCH magnitude and rms, year range, and magnitude ranges. These statistics provide the basis for a search for interesting variable stars.
starsummary1	Contains statistics of stars in the stars1 table processed with the Kepler Input Catalog instead of the GSC2.3.2 catalog
starsummary2	Contains statistics of stars in the stars1 table processed with the APASS catalog instead of the GSC2.3.2 catalog
calibration	Contains the relationship between SExtractor instrumental magnitude and GSC2.3.2 catalog magnitude for each plate and annular bin and the estimated RMS error for this relationship.
calibration1	Contains the relationship between SExtractor instrumental magnitude and Kepler Input Catalog magnitude for each plate and annular bin and the estimated RMS error for this relationship.
calibration2	Contains the relationship between SExtractor instrumental magnitude and APASS Catalog magnitude for each plate and annular bin and the estimated RMS error for this relationship.

Auxscanner Database

The auxscanner database contains tables which do not require periodic backup either because they are generated from text files or from other database tables.

loglinks	Contains a linked list of all logbook page photographs for use by the logbook browser on this website.
logindexnew	Contains the logbook volume and page number for all plates. Used by the logbook browser on this website.
coverage	Contains a list of all plates indexed by one degree square regions of the sky. Used by the lightcurve generator.
disks	Contains a list of all disks and raid arrays used by the DASCH project.
variables	Contains the list of database variables listed in the Database Variables table below. Used for generation of VOTables

Database Variables

The remainder of this page contains reference tables useful mostly to the DASCH pipeline developers and to researchers who have been provided with DASCH photometry results.

Table of Variables Used in the Photometry Database

variableName	datatype	unit	variableDescription
adjacentburstdip	int	ct	A measure of the number of adjacent nburst3/4 and ndip3/4 points in a lightcurve
adjacentburstdip2	int	ct	A measure of the number of >5 adjacent nburst3/4 and ndip3/4 points in a lightcurve
adjacentburstdip3	int	ct	A measure of the number of >7 adjacent points 2-sigma above or below the median value of a lightcurve
AFLAGS	int		Fatal image flags
aLength	double	pix	Image long semi-axis in pixels
alternateDate	char	Y-M-D,h:m:s	Alternate dark, flatfield, or linearity test for failed test
altitude	double	deg	Height of the object above the horizon in degrees
aperture	double	m	Telescope aperture in meters. Some series, notably mb, contain plates from serveral telescopes.
arraysize	int	ct	Length of a variable character string
aveADU	int	ct	Average ADU level for all of the tile
aveTileSaturation	int	ct	Average number of saturated pixels per tile
BACKGROUND	double	ct	Background at centroid position
BFLAGS	int		Non-Fatal image flags
binning	int		Binning (1x1 or 16x16) of the mosaic used for WCS fitting
bin_count	int	ct	Number of images in a spatial bin.
Blendedmag	double	mag	For case B and BD objects, the effective magnitude of all of the GSC2.3.2 objects within the blend.
bLength	double	pix	Image short semi-axis in pixels
border	int	pix	Crop border in pixels. WCStools 'imwcs' input parameter.
bottomMargin	int	pix	Bottom margin in pixels
bound	enum	bit	Bound 'b' or unbound 'u' logbooks
bright_magcor_error	double	mag	magcal_local_error for brightest two magnitudes
bright_magcor_local	double	mag	magcor_local for brightest two magnitudes
bright_npoints_local	int	ct	npoints_local for brightest two magnitudes
calcTimeType	char		Calculated Date Type: (EST, LST, UT, SAST, ...)
calibrationDate	char	Y-M-D,h:m:s	Date of dark, flatfield, or linearity test
calibrationStatus	set		calibration test status: acquired, processed, failed, or deleted
calibrationType	set		calibration test type: dark, flat, or linearity
CAL_FLAG	int		Deprecated, now part of BFLAGS
cal_local	int	bit	If 1, local calibration was used; otherwise 0; becomes part of BFLAGS
capacity	int	byte9	Disk capacity in gigabytes
catalog	enum		Fitting catalog 'imwsky2k' or 'imwty2'. WCStools 'imwcs' input parameter.
cd1_1	double	deg/pix	Change in RA---TAN along X axis
cd1_2	double	deg/pix	Change in RA---TAN along Y axis
cd2_1	double	deg/pix	Change in DEC--TAN along X axis
cd2_2	double	deg/pix	Change in DEC--TAN anong Y axis
cdec	double	deg	Search center or plate center Declination in degrees
centerDrift	int	pix	Center drift of solution in pixels
centerSource	enum		Source of J2000 RA and DEC 'Catalog', 'Logbook','imWCS' or 'WCS'
chn	int		Kepler satellite CCD channel
class	int		GSC2.3.2 object type 0 = star 3 = non-star; also synonym for plateClass
classDescription	char		Description of plate class
clip_median_local	double	mag	Median DASCH magnitude of clipped dataset
clip_ngood	int	ct	Clipped number of points to compute the clipped median DASCH magnitude
clip_rms_local	int	mag	DASCH magnitude RMS of the clipped dataset
col	double		Kepler satellite CCD column
color	double	mag	magj-magf
colorflag	enum		Color correction flag 'linear', 'metropolis' or 'copy'
colorterm	double		Color correction term, multiply by color and subtract to convert locally calibrated magnitudes to catalog color system
comments	char		Disk event comments
correlationLimit	int	pix	WCS fitting correlation limit in pixels. WCStools 'imwcs' input parameter.
count	int	ct	Count of good stars in the summary file or count of mosaics for dxmedian and dymedian
coverage_bin_index	int		Coverage bin index (approximately 1 square degree of sky)
cra	double	deg	Search center or plate center Right Ascension in degrees
crpix1	double	pix	X-axis reference pixel
crpix2	double	pix	Y-axis reference pixel
crval1	double	deg	X-axis coordinate value
crval2	double	deg	Y-axis coordinate type
ctype1	char		X-axis coordinate type
ctype2	char		Y-axis coordinate type
currentVersion	int		Latest version of the photometry database
damonBlueRms	double	mag	RMS of good lightcurve magnitudes in dnb and dsb plates
Damon_factor	double	mag	difference in clipped DASCH median magnitude for the dnb and dsb series and all non-Damon plates
daschProcessor	int	ct	server on which the photometry pipeline has been executed for this plate.
datatype	enum		Variable datatype ('char', 'double', 'int', 'short', 'enum', 'set' or 'long')
date	char	Y-M-D,h:m:s	Geocentric exposure date (See ExposureDate for Date)
ddec	double	arcsec	difference between catalog and image declination in arcseconds.
dDeclination	double	deg	Decimal J2000 declination in degrees
ddecMedian	double	arcsec	Median declination error in arcsec per smoothing bin (tnx fitting quality in filterblended)
ddecMedian2	double	arcsec	Median declination error in arcsec per smoothing bin (final tnx adjustment in recover_points)
ddecRMS	double	arcsec	RMS declination error in arcsec per smoothing bin (tnx fitting quality in filterblended)
ddecRMS2	double	arcsec	RMS declination error in arcsec per smoothing bin (final tnx adjustment in recover_points)
dec	double	deg	Declination in degrees
decimalPlaces	int		Variable field precision
declination	double	deg	Synonym for dec to avoid MySQL keyword
declinationString	char	deg	Synonym for dec to avoid MySQL keyword
decPixels	double	pix	Offset in declination pixels from the previous exposure
DecPM	double	mas/yr	Declination proper motion in mas/yr
decrms	double	deg	Standard deviation of lightcurve dec
dec_1	double	deg	Image declination from sextractor
dec_2	double	deg	Catalog star declination
degDrad	double	deg	difference between GSC2.3.2 and Kepler Input Catalog positions in degrees
description	char		Description of pattern, or telescope
diskLocation	int		Disk raid array number containing the scan tiles or mosaic
diskStatus	enum		Disk status 'InService', 'Spare', 'Failed' or 'Returned'
dix	int		x bin index in calculation of dxmedian and dymedian
diy	int		y bin index in calculation of dxmedian and dymedian
dmagcatalog	double	mag	The differences between catalog magnitude and median magnitude in the plates
dmag_iso	double	mag	difference between the lowess-fitted magnitude and catalog magnitude
dmag_local	double	mag	difference between locally corrected calibrated isophotal magnitude and the catalog magnitude
dnx	int	ct	Number of horizontal bins in calculation of dxmedian and dymedian
dny	int	ct	Number of vertical bins in calculation of dxmedian and dymedian
dra	double	arcsec	difference between catalog and image right ascension in arcseconds
drad	double	arcsec	difference between catalog and image position in arcseconds
dradAverage	double	arcsec	The average astrometric mismatch error for a local bin in arcseconds.
dradB	double	arcsec	RMS uncertainty in arcsec for good points, defects, low altitude, uncertain date, and second quality plates
dradRMS2	double	arcsec	RMS positional error in arcsec per smoothing bin (final tnx adjustment in recover_points)
drad_bin_count	int	ct	Number of stars used to compute draMedian and ddecMedian (tnx fitting quality in filterblended)
drad_bin_count2	int	ct	Number of stars used to compute draMedian and ddecMedian (final tnx adjustment in recover_points)
drad_bin_size	int	ct	Number of smoothing bins used to compute draMedian and ddecMedian (tnx fitting quality in filterblended)
drad_bin_size2	int	ct	Number of smoothing bins used to compute draMedian and ddecMedian (final tnx adjustment in recover_points)
drad_reject_count	int	ct	Stars rejected for high drad (tnx fitting quality in filterblended)
drad_reject_count2	int	ct	Stars rejected for high drad (final tnx adjustment in recover_points)
draMedian	double	arcsec	Median Right Ascension error in arcsec per smoothing bin (tnx fitting quality in filterblended)
draMedian2	double	arcsec	Median Right Ascension error in arcsec per smoothing bin (final tnx adjustment in recover_points)
draRMS	double	arcsec	RMS Right Ascension error in arcsec per smoothing bin (tnx fitting quality in filterblended)
draRMS2	double	arcsec	RMS Right Ascension error in arcsec per smoothing bin (final tnx adjustment in recover_points)
dRightAscension	double	deg	J2000 Right ascension in degrees
dxmedian	double	pix	median x-axis angular difference in pixels between TNX and TAN fits.
dxrms	double	pix	RMS of the x-axis angular difference in pixels between TNX and TAN fits.
dxval	double	pix	x-axis angular difference in pixels between TNX and TAN fits
dymedian	double	pix	median y-axis angular difference in pixels between TNX and TAN fits.
dyrms	double	pix	RMS of the y-axis angular difference in pixels between TNX and TAN fits.
dyval	double	pix	y-axis angular difference in pixels between TNX and TAN fits.
eix	int		x position of an extinction bin (0-49)
eiy	int		x position of an extinction bin (0-49)
elevation	double	m	Elevation above sea level in meters
ELLIPTICITY	double		See sextractor manual. (1 - B_IMAGE/A_IMAGE)
enableFindWCS	enum	bit	Set to 'no' to abort FindWCS or AstronmetryWCS execution; otherwise 'yes'
enx	int		Number of horizontal bins in an extinction table
eny	int		Number of vertical bins in an extinction table
epoch	double	yr	Database epoch
equinox	double	yr	Database equinox
ERRA_IMAGE	double	pix	RMS position error along major axis. See sextractor manual
ERRA_WORLD	double	deg	World RMS position error along major axis. See sextractor manual.
ERRB_IMAGE	double	pix	RMS position error along minor axis. See sextractor manual.
ERRB_WORLD	double	deg	World RMS position error along minor axis. See sextractor manual.
errorcolor	double		RMS Error in the color correction term
errorType	set		Logbook error type
error_bar_factor	double		Error bar factor: min(1.0,the median RMS of the lightcurve divided by the median zero-based RMS of the local calibration RMS of all of the individual points in the lightcurve)
errout	double	mag	Local correction error
ERRTHETA_IMAGE	double	deg	RMS position error along minor axis. See sextractor manual.
ERRTHETA_J2000	double	deg	J2000 error ellipse pos. angle (east of north)
ERRTHETA_WORLD	double	deg	World RMS position error along major axis. See sextractor manual.
eventDate	char	Y-M-D,h:m:s	Disk event date
exposure	char	min	Logbook exposure time, normally in minutes but may be qualified by other units
ExposureDate	double	JD	Geocentric Julian date of plate or Heliocentric Julian date of an image
exposureNumber	int	ct	The zero-based exposure number listed in the logbooks, or -1 if WCS fitting finds more solutions than logbook entries.
exposures	int	ct	Number of exposures fitted for this plate
extinction	double	mag	Extinction estimate for an image.
fatalError	int		terminating condition of the photometry pipeline for this plate.
fatalSolution	int	ct	terminating solutionNumber of the photometry pipeline for this plate
fileExists	int		1 if the drad file associated with a plate exists; 0 otherwise
fileObsolete	int		1 if the drad file associated with a plate is obsolete; 0 otherwise
fileOffset	int		Byte position offset of the gsc bin into a photometry database file
firstPlate	int		Initial plate number in the range
fittedPlateScale	double	arcsec/m-3	Average plate scale from available WCS fits in arc seconds per mm
FitWCS	set		WCS fitting and pipeline status
flag	double		Plotting flag.
flaggrid	int		calibration table entry type 0 = too bright, 1 = valid, -1 = too dim
FLAGS	int		Photometry flag defined by sextractor. See sextractor manual.
FLUXERR_AUTO	double	ct	RMS error for AUTO flux. See sextractor manual.
FLUXERR_ISO	double	ct	RMS error for isophotal flux. See sextractor manual.
FLUX_AUTO	double	ct	Flux within a Kron-like elliptical aperture. See sextractor manual.
FLUX_ISO	double	ct	Isophotal flux. See sextractor manual.
FLUX_MAX	double	ct	Peak flux above background. See sextractor manual.
fraction	double		Fractional extra stars used for WCS fitting. WCStools 'imwcs' input parameter.
FWHM_IMAGE	double	pix	FWHM assuming a gaussian core. See sextractor manual.
FWHM_WORLD	double	deg	FWHM assuming a gaussian core. See sextractor manual.
gmag	double	mag	SDSS g magnitude
goodBins	int	ct	number of local smoothing bins without any error flags set
goodDradBins	int	ct	number of local smoothing bins with acceptable positional errors
goodLocalBins	int	ct	number of local smoothing bins with local smoothing correction values
goodMedianBins	int	ct	number of local smoothing bins where the median Stdmag is less than the ((median limiting_mag) + 0.5) magnitudes
goodZoutBins	int	ct	number of local smoothing bins with acceptable local smoothing corrections
griderr	double	mag	lowess fit error in the calibration table
group	int		The number of each group of unmatched catalog images associated with a single source
groupCount	int	ct	The count of unmatched catalog images associated with a single source
gsc2_id	char		GSC2 star ID, becomes REF in subsequent tables
GSCBlendFlag	int	bit	If 1, the unmatched image is too close to a bright GSC2.3.2 catalog star; 0 otherwise
gscclass	int		GSC2.3.2 star class 0 = star; 3 = non-star
gsccolor	double	mag	GSC (JpgMag - FpgMAG) also expressed as ( magj-magf)
gsc_bin_index	int		A spatial index of approximately 1/4096 degree used to sort images in the input star catalog and the photometry database.
hJD	double	JD	Heliocentric Julian Day
hourAngle	char	HH:MM:SS	Logbook hour angle
imagb	int	ct	magnitude index for magnitude-dependent calibration
iMAG_ISO	int		Standard sextractor MAG_ISO bin index. There are 220 bins between MAG_ISO = -22 and MAG_ISO = 0.0
index	int		gsc bin offset into a photometry database file. Add to the base index to get gsc_bin_index
inventory	enum	bit	If 'yes' disk found during inventory; otherwise 'no'
ISO0	int	pix2	Isophotal area at level 0. See sextractor manual.
ISO1	int	pix2	Isophotal area at level 1. See sextractor manual.
ISO2	int	pix2	Isophotal area at level 2. See sextractor manual.
ISO3	int	pix2	Isophotal area at level 3. See sextractor manual.
ISO4	int	pix2	Isophotal area at level 4. See sextractor manual.
ISO5	int	pix2	Isophotal area at level 5. See sextractor manual.
ISO6	int	pix2	Isophotal area at level 6. See sextractor manual.
ISO7	int	pix2	Isophotal area at level 7. See sextractor manual.
ISOAREA_IMAGE	double	pix2	Isophotal area above Analysis threshold. See sextractor manual.
ISOAREA_WORLD	double	deg2	Isophotal image area in square degrees. See sextractor manual.
isogrid	double	mag	isophotal magnitude in calibration table
ix	int		x position of a local calibration bin (0-49)
ixb	int	ct	x index for magnitude-dependent calibration
iy	int		y position of a local calibration bin (0-49)
iyb	int	ct	y index for magnitude-dependent calibration
jacketJPEG	enum	bit	If 'yes' a plate jacket JPEG image is available, otherwise 'no'
julianDate	char	JD	Julian Date from logbook
keepalive	enum	bit	Set to 'no' when aborting a photometry database update, otherwise 'yes'
keplerField	enum	bit	If 'yes', object is on a Kepler CCD chip. Otherwise 'no'
kmagb	int	ct	Number of magnitude bins for magnitude-dependent calibration
KRON_RADIUS	double		Kron apertures in units of A or B. See sextractor manual.
kxb	int	ct	Number of x bins for magnitude-dependent calibration
kyb	int	ct	Number of y bins for magnitude-dependent calibration
lastPlate	int		Last plate number in the range.
latitude	double	deg	Observatory latitude in degrees
leftMargin	int	pix	Left margin in pixels
lightcurveCount	int	ct	Number of lightcurves on this plate
lightcurverms1	double	mag	5-sigma clipped RMS of good lightcurve points
lightcurverms2	double	mag	5-sigma clipped RMS of good lightcurve points after detrending (smooth(x,y,0.4,'lowess'))
lightcurverms3	double	mag	5-sigma clipped RMS of good lightcurve points after detrending (smooth(y,0.8,'lowess'))
lightcurverms4	double	mag	5-sigma clipped RMS of good lightcurve points after detrending (smooth(y,10,'sgolay'))
lightcurverms5	double	mag	5-sigma clipped rms of good lightcurve points after detrending (smooth(y,15,'loess'))
limiting_iso	double	mag	Instrumental isophotal magnitude which corresponds to the lowess limiting magnitude
limiting_mag	double	mag	lowess limiting magnitude
limiting_mag_local	double	mag	Locally corrected limiting magnitude
line	int		Line number of the logbook transcription
listName	char		Filename containing a list of plates
local_bin	short		Local calibration bin number (ix + (nx * iy))
local_bin_index	short		Local calibration bin number (ix + (nx * iy))
locationId	int		Telescope location index
logPage	char		Logbook volume and page
logRemark	enum	bit	If 'Y' a logbook remark is present, otherwise 'N'. Deprecated.
logTimeType	char		Date type given in the logbook ('EST', 'LST', 'UT', 'SASE' ...)
magcal_iso	double	mag	magnitude estimate from lowess fitting
magcal_iso_error	double	mag	- plate overall rms error between the lowess and catalog magnitude.
magcal_iso_rms	double	mag	error in the lowess fitting algorithm
magcal_local	double	mag	locally corrected magnitude
magcal_local_error	double	mag	(ERROUT in contour_plot_clip_smooth_correct2.f) rms of the needed median magnitude correction
magcal_local_rms	double	mag	Error of the locally corrected magnitude.
magcal_magdep	double	mag	magnitude-dependent corrected magnitude
magcal_magdep_rms	double	mag	Error of the magnitude-dependent correction
magcor_local	double	mag	(ZOUT in contour_plot_clip_smooth_correct2.f) median magnitude correction needed in a given plate ragion
magcor_local_range	double	mag	Deprecated. Range in magcor_local within a smoothing bin.
magcor_rmsbright	double	mag	Deprecated. magcor_local_rms of the 30 brightest stars in a local smoothing bin.
magcor_rmsdim	double	mag	Deprecated. magcor_local_rms of the 30 dimmest stars in a local smoothing bin.
magdep_bin	int		Magnitude-dependent calibration bin number (ixb + (kxb*iyb) * (kxb*kyb*imagb))
magdep_bin_edge	double	mag	Dimmest GSC2.3.2 magj magnitude in a magnitude correction bin
magdep_bin_magcor	double	mag	median magnitude magnitude-dependent correction
magdep_bin_median	double	mag	Median GSC2.3.2 magj magnitude in a magnitude correction bin
magdep_bin_quality	double	mag	Magnitude dependent bin quality measure (magdep_bin_magcor * sqrt(nstar_magdep))/magcal_magdep_rms
magdep_bin_size	int	ct	Bin expansion factor for magnitude-dependent correction
magdiff	double	mag	Magnitude difference between GSC JpgMag and SDSS gmag
MAGERR_APER	double	mag	RMS error vector for fixed aperture mag.
MAGERR_AUTO	double	mag	RMS error for AUTO magnitude
MAGERR_ISO	double	mag	RMS error for isophotal magnitude
magf	double	mag	GSC2 red magnitude.In subsequent tables color = magj - magf
MAGFlag	int		GSC2.3.2 magnitude origin
maggrid	double	mag	best lowess fit magnitude in calibration table
magj	double	mag	GSC2 blue magnitude, becomes Stdmag in subsequent tables
magnitudeFile	enum	bit	If 'yes' magnitudes are in a file, if 'no' magnitudes are in a MySQL table.
magvsdeccorr	double	mag	Correlation coef. between lightcurve magnitude and dec
magvslimitingcorr	double	mag	correlation coef. between lightcurve magnitude and limiting magnitude
magvsracorr	double	mag	Correlation coef. between lightcurve magnitude and ra
MAG_APER	double	mag	Fixed aperture magnitude vector. See sextractor manual.
MAG_AUTO	double	mag	Kron-like elliptical aperture magnitude. See sextractor manual.
MAG_ISO	double	mag	See sextractor manual. isophotal magnitude
Malmquist_factor	double	mag	clipped median DASCH magnitude of 20 deepest plates - clipped median DASCH magnitude of 20 shallowest plates using good points
Malmquist_factorB	double	mag	clipped median DASCH magnitude of 20 deepest plates - clipped median DASCH magnitude of 20 shallowest plates using good points, defects, low altitude, uncertain date, and second quality plates
maskNumber	int		Last plate number in the mask pseudo-series
MATCH_NUMBER	int		The sextractor image NUMBER that a Pickering Wedge ghost image is associated with
maxDist1	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 1
maxDist2	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 2
maxDist3	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 3
maxDist4	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 4
maxDist5	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 5
maxDist6	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 6
maxDist7	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 7
maxDist8	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 8
maxDist9	double	pix	Maximum difference in pixels between TNX and TAN fits for spatial_bin 9
maxmag	int	mag	Maximum bin magnitude in the summary file.
maxmagdiff	double	mag	maximum magnitude difference between spatial bins for a given MAG_ISO
maxSpatialBins	int		Maximum number of annular bins, normally 9
maxTileSaturation	int	ct	Maximum number of saturated pixels in any tile
max_bright_iso	double	mag	Isophotal magnitude corresponding to the brightest reliable magnitude in a spatial bin.
max_bright_mag	double	mag	Brightest reliable lowess magnitude in a spatial bin.
max_drad	double	arcsec	Maximum difference between catalog and image position in arcseconds for good points
max_dradB	double	arcsec	Maximum difference between catalog and image position in arcseconds for good points, defects, low altitude, uncertain date, and second quality plates
max_local	double	mag	Dimmest locally corrected magnitude for a lightcurve
max_local2	double	mag	Second dimmest locally correccted magnitude for a lightcurve
medDamonBlue	double	mag	Median of good lightcurve magnitudes in dnb and dsb plates
median	double	mag	Median RMS in the summary file
medianStdmag	double	mag	The median magnitude of GSC2.3.2 images rejected by matchstars and filterblended because there are not enough sextractor images to match them with
median_drad	double	arcsec	Median astrometric error in arcseconds within a spatial bin.
median_iso	double	mag	Median lowess magnitude in a lightcurve
median_local	double	mag	Median locally corrected magnitude in a lightcurve
medNonDamonBlue	double	mag	Median of good lightcuve magnitudes excluding dnb and dsb plates
minmag	int	mag	Minimum bin magnitude in the summary file.
minVersionId	int		Minimum valid versionId
min_local	double	mag	Brightest locally corrected magnitude in a lightcurve
min_local2	double	mag	Second brightest locally corrected magnitude in a lightcurve
model	char		Disk model from manufacturer
mosaic	char		Synonym for plate or Plate
mosaicBinning	set		Binning of available mosaics
mosaicComment	char		Mosaic comment
mosaicDate	char	Y-M-D,h:m:s	Date mosaic was generated
mosaicHeight	int	pix	Mosaic height in pixels
mosaicNumber	int	ct	Mosaic number for this plate
mosaicWidth	int	pix	Width of this mosaic
n1	int	ct	Total points read by annular9.m for a lowess fit attempt.
n2	int	ct	Actual number of points used by annular9.m for a lowess fit attempt.
name	char		Name of the observing station
naxis1	int	pix	Length of the x axis of the image in pixels (width)
naxis2	int	pix	Length of the y axis of the image in pixels (height)
nblend	int	ct	Number of blended lightcurve points
nburst	int	ct	Number of good lightcurve points 0.8 mag above the median value
nburst2	int	ct	Number of good lightcurve points 0.5 mag above the median value
nburst3	int	ct	Number of good lightcurve points 0.4 mag above the median value
nburst4	int	ct	Number of good lightcurve points 3-sigma above the median value
nDamonBlue	int	ct	Number f good lightcurve points in dnb and dsb plates
ndev2	int	ct	Number of good lightcurve points 2-sigma from the median value
ndev3	int	ct	Number of good lightcurve points 3-sigma from the median value
ndip	int	ct	Number of good lightcurve points 0.8 mag below the median value
ndip2	int	ct	Number of good lightcurve points 0.5 mag below the median value
ndip3	int	ct	Number of good lightcurve points 0.4 mag below the median value
ndip4	int	ct	Number of good lightcurve points 3-sigma below the median value
nextbound	enum	bit	Next bound ('b') or unbound ('u') logbook in logbook browser linked list
nextpage	int		Next logbook page number in logbook linked list
nextseries	char		Next logbook series in logbook linked list
nextvolume	int		Next logbook volume in logbook linked list
ngood	int	ct	Number of good points in a lightcurve. (AFLAGS = 0 with ra and dec filtering)
ngoodB	int	ct	Number lightcurve points with good points, defects, low altitude, uncertain date, and second quality plates.
nlocal	int	ct	Number of good images in a local correction bin.
nmatch	int	ct	Number of stars matched during WCS fitting. WCStools 'imwcs' result.
nNonDamonBlue	int	ct	Number of good lightcurve points excluding dnb and dsb plates
nominalPlateScale	double	arcsec/m-3	Nominal plate scale in arc seconds per mm
nonDamonBluerms	double	mag	RMS of good lightcurve magnitudes excluding dnb and dsb plates
normadjacentburstdip2	double	ct	Normalized adjacentburstdip2: Number of good lightcurve points 3-sigma above the median value divided by number of lightcurves with valid adjacentburstdip2 values
normnburst3	double	ct	Normalized nburst3: Number of good lightcurve points 3-sigma above the median value divided by number of lightcurves with valid nburst3 values
normnburst4	double	ct	Normalized nburst4: Number of good lightcurve points 3-sigma above the median value divided by number of lightcurves with valid nburst4 values
notes	char		Logbook transcription comment
nplot	int	ct	Number of default points plotted in a lightcurve.
npoints	int	ct	Total number of points, good and bad, in a lightcurve.
npoints_local	int	ct	(NPOUT in contour_plot_clip_smooth_correct2.f) number of stars used for the median magnitude correction
npout	int	ct	number of stars used for the median magnitude correction
nslope_60	int	ct	Number points in a lightcurve used to calculate slope_60.
nslope_all	int	ct	Number of points used to calculate slope_all.
nstar_magdep	int	ct	number of bin stars used for the magnitude-dependent correction
NUMBER	int		Sextractor object number in an image. See sextractor manual.
numfake	int	ct	Number of images not matching GSC2.3.2 objects during defect filtering
numreal	int	ct	Number of images matching GSC2.3.2 objects during defect filtering.
numTiles	int	ct	Number of tiles in the scan pattern
nx	int		Number of horizontal bins in a local calibration table
ny	int		Number of verticalbins in a local calibration table
oldNumber	char		Original plate number for renamed plates
orientation	enum		Series plate orientation North Forward or Left, Mirrored (deprecated)
outlierCount	int	ct	Number of outlier images on this plate
outlierRatio	double		Fraction of images on this plate which are outliers
page	int		Logbook page number synonym for logPage
passBits	int		Pass identifier. Unused, only bit 1 GSC2.3.2 pass1 is recognized
patternID	int		Scan pattern
Plate	char		HCO plate designation (series and number within series)
plateClass	char		Plate class
plateJPEG	enum	bit	If plate JPEG exists, 'yes'; otherwise 'no'
plateNumber	int		The sequential number assigned to a plate in a given plate series from a single telescope or lens
plateVersionId	int		Version Id from the photplates table
plate_ddec	double	deg	declination distance in degrees from the plate center
plate_dist	double	deg	distance in degrees from the plate center
plate_dra	double	deg	right ascension distance in degrees from the plate center
PolyDecRMS	double	pix	RMS declination error in pixel from SCAMP polynomial fitting
PolyRARMS	double	pix	RMS Right Ascension error in pixels from SCAMP polynomial fitting
PolyRefStars	int	ct	Number of reference stars used for SCAMP polynomial fitting
port	char		Disk drive raid array port
precessionCorrected	enum	bit	If 'yes', precession error has been corrected, otherwise 'no'. Deprecated
prevbound	enum	bit	Previous bound ('b') or unbound ('u') volume in logbook linked list
prevpage	int		Previous page in the logbook linked list
prevseries	char		Previous series in the logbook linked list
prevvolume	int		Previous volume in the logbook linked list
qualifier	char		Source of the plate class information
quality	set		Plate quality flags
ra	double	deg	Right Ascension in degrees
raidArray	int		Raid array number of which the disk is part of
raidDisk	char		Location in the disk raid array (one-based)
range_iso	double	mag	The magnitude range of the lowess magnitude in a lightcurve
range_local	double	mag	The magnitude range of the locally corrected magnitude in a lightcurve
range_local2	double	mag	The magnitude range from the second brightest to the second dimmest magnitude in a lightcurve
raPixels	double	pix	Offset in Right Ascension pixels from the previous exposure
RaPM	double	mas/yr	Right Ascension proper motion in mas/yr
rarms	double	deg	Standard deviation of lightcurve ra
ratio1	double		In defect filtering, the number of images flagged as real divided by the number of images matching the GSC2.3.2 catalog
ratio2	double		In defect filtering, the number of images flagged as not real divided by the number of images not matching the GSC2.3.2 catalog
ratio3	double		In defect filtering, the ratio of images matching the GSC2.3.2 catalog and the images not matching the GSC2.3.2 catalog.
ra_1	double	deg	Image Right Ascension from sextractor
ra_2	double	deg	Catalog star Right Ascension
recordId	int		Unique MySQL table index
REF	char		The GSC2.3.2 ID.
reference	int		Page reference in History of the Plate Series by Martha Hazen
refmag	double	mag	Synonym for the Stdmag, the GSC2.3.2 magnitude.
REFNumber	long		Star reference designation expressed as an integer
refstars	int	ct	Number of reference stars to use for WCS fitting. WCStools 'imwcs' input parameter.
rejectFlag	int		Local calibration bin rejection reason.
reject_count	int	ct	Number of images rejected because of high drad in a spatial bin.
reject_reason	int		Lightcurve rejection reason.
reject_reason1	int		Unmasked reject_reason for a lightcurve image
reject_reason2	int		Masked reject_reason for a lightcurve image
rightAscension	char	HH:MM:SS	J2000 Right Ascension
rightMargin	int	pix	Right margin in pixels
rms	double	mag	The average locally corrected magnitude rms error for an entire spatial bin.
rmsdradrms2	double	mag	Standard deviation of lightcurve dradRMS2
rms_factor	double	mag	RMS of the lightcurve divided by the median error; valid variables have a larger rms_factor
rms_local	double	mag	In annular9.m, the RMS of the locally corrected good magnitudes in a lightcurve.
rotation	int	deg	Angle in degrees between original mosaic and mosaic with North up.
row	double		Kepler satellite CCD row
scale	double	arcsec/pix	Plate scale in arcsec per pixel
scale1	double	arcsec/pix	Fitted scale in arcsec per pixel, first coordinate. WCStools 'imwcs' result.
scale2	double	arcsec/pix	Fitted scale in arcsec per pixel, second coordinate WCStools 'imwcs' result.
scaleDrift	double		Scale drift during WCS fitting. (1- ratio of scales).
scalex	double	arcsec/pix	x-axis arcseconds per pixel
scaley	double	arcsec/pix	y-axis arcseconds per pixel
scanComment	char		Scan comment
scanDate	char	Y-M-D,h:m:s	Date scanned
scanExposure	double	s-3	Scanner exposure time in milliseconds
scanNumber	int		Scan number for this plate
sdsscolor	double	mag	SDSS g - r color
separation	double	pix	Fitting separation in pixels (obsolete use in arcsec in fithistory). WCStools 'imwcs' result.
sequence	int		Measurement position within a lightcurve graph
serial	char		Disk serial number
series	char		Plate series indicating the telescope or lens used to photograph the plate
seriesId	int		Index into the plate series table
Sextractor_Blend	double	ct	Number of good points with the sextractor blend or neighbors bits set
SEXTRNUMBER	int		Synonym for NUMBER to avoid MySQL keyword
SFLAGS	int		FLAGS bits from sextractor
slope_60	double	mag-3/yr	lightcurve slope for points before 1960
slope_60_err	double	mag-3/yr	lightcurve slope standard deviation for points before 1960
slope_all	double	mag-3/yr	lightcurve slope
slope_all_err	double	mag-3/yr	lightcurve slope standard deviation
solutionHeader	enum	bit	If 'no', the exposureNumber column is really the solutionNumber; otherwise 'yes'
solutionNumber	int		The zero-based exposure number in the order found by astrometry.wcs in a multiple exposure image
source	enum		Source of plates table entry 'Catalog','Logbook', or 'JPEG' expanded with 'logindex','estimate', or 'noknownlog' in logindexnew
spatial_bin	short	byte	annular ring on the plate where the star appears (1 = centermost, 9 = outermost)
squareBorder	enum	bit	If 'yes' solution used a square region; otherwise 'no'. WCStools 'imwcs' input parameter.
src_name	char		Search query source name
starCount	int	ct	Number of images in for the gsc bin in a photometry database file
start	char	HH:MM:SS	Logbook time of exposure start
status	enum	bit	WCS fit result 'succeeded' or 'failed'
Stdmag	double	mag	GSC2.3.2 magj magnitude
stop	char	HH:MM:SS	Logbook time of exposure end
suffix	char		Suffix for duplicate plate numbers
suffixBase	int		Suffix base for duplicate plate numbers. Original plateNumber is (plateNumber - suffixBase)
THETA_IMAGE	double	deg	Position angle (CCW/x) determined by sextractor
THETA_J2000	double	deg	Image angle in degrees East of North. See sextractor manual.
THRESHOLD	double	ct	Detection threshold above background. See sextractor manual.
tile	int		Tile position number in the scan pattern. Actual tiles have name Exposure_'tile'.fit
timeAccuracy	double	d	Accuracy of logbook time in days
timeSource	enum	bit	Exposure time source, either 'Catalog' or 'Logbook'
timeSpent	int	s	Seconds used for WCS fitting
timeStamp	char	Y-M-D,h:m:s	Time of last write to the database
timeType	char		Known date type ('EST', 'LST', 'UT', 'SASE' ...)
tolerance	int	pix	WCS fitting tolerance in pixels. WCStools 'imwcs' input parameter.
topMargin	int	pix	Top plate margin in pixels
transform	set		Transform between scan and mosaic 'Flip' and/or 'Mirror'. Used with 'rotation' to match raw tiles with positions in the final mosaic.
ucd	char		Unified Content Descriptor
unbound	enum	bit	Logbook volume is bound if 'b' otherwise 'u'
uncertain	enum	bit	If 'yes', there is uncertainty in the location
unit	char		Variable physical unit
unmatched	int	ct	Number of good (AFLAGS == 0) images unmatched to the catalog for a plate
updateflag	enum	bit	If 'yes' then the star summary data needs to be updated; otherwise 'no'
upper_limit	double	mag	upper limit: limiting_mag - 2*error, where the error is the overall RMS in the annular9.m photom fitting
variableDescription	char		Description of variable
variableName	char		Variable name in this table
verified	enum	bit	Observatory location is approximate if 'no'; otherwise 'yes';
version	char	Y-M-D,h:m:s	Date logbook transcription was last edited
versionDate	char	Y-M-D,h:m:s	Photometry data version date
versionId	int		Index into the photometry version table for GSC2.3.2 stars
versionId1	int		Index into the photometry version table for Kepler Input Catalog stars
versionId2	int		Index into the photometry version table for APASS catalog stars
versionName	char		Photometry data version name
VFlag	int	bit	If nonzero, the catalog star is considered to be variable.
volume	int		Logbook volume numbers
wcsnref	int	ct	Number of stars used for WCS matching
WCSSource	enum	bit	Source of the WCS fit, either 'Logbook' or 'imWCS'
width	int	pix	Mosaic width
wLongitude	double	deg	West Longitude of the observatory in degrees
xbins	int		Number of horizontal smoothing bins (normally 50)
xcoord_magdep	double	pix	x-axis center of the magnitude-dependent correction bin
xPos	double	m-3	Aerotech X position for the tile
xval	double	pix	x-axis position in pixels for calculation of dxmedian and dymedian.
X_IMAGE	double	pix	Mosaic x-axis pixel position of the image. See sextractor manual.
X_WORLD	double	deg	Barycenter position along world x axis. See sextractor manual.
ybins	int		Number of vertical smoothing bins (normally 50)
ycoord_magdep	double	pix	y-axis center of the magntiude-dependent correction bin
year	double	yr	Calendar year of an image
yPos	double	m-3	Aerotech Y position for the tile
yrbegin	double	yr	Beginning calendar year of a lightcurve
yrend	double	yr	Ending calendar year of a lightcurve
yval	double	pix	y-axis position in pixels for calculation of dxmedian and dymedian
Y_IMAGE	double	pix	Mosaix y-axis pixel position of the image. See sextractor manual.
Y_WORLD	double	deg	arycenter position along world y axis. See sextractor manual.
zout	double	mag	median magnitude correction needed in a given plate ragion

Number of database variables: 486

Notes on Database Variables

Plate Selection

Plates are referenced by a plate series which usually identifies individual telescopes; and a plate number, which usually increases monotonically for every plate exposed at the telescope. Any disk files related to a plate have the extended designation:
{series}{plateNumber}_{mosaicNumber}_{binning}{rotationString}ww{solutionString}{qualifierString}{fileSuffix}
where
rotationString is null for zero degrees and r{rotation} for other angles
solutionString is null for the first solution and _s{solutionNumber} for successive solutions of a multiple-exposure plate
qualifierString is null for the primary GSC2.3.2-calibrated database stream, _{qualifier} for alternate streams such as 'kepler' for photometry data calibrated with the Kepler Input Catalog and 'apass' for data calibrated with the APASS catalog)
fileSuffix defines the type of file.

Observatory Location

Telescopes did not necessary remain at one location but were moved between observatories worldwide

Plate Class

The plate class serves to identify the kind of exposure that was taken and is useful in filtering out plates that may require special techniques for analysis or for selecting plates taken with particular filters or gratings.

Plate Jacket Photographs

Prior to scanning, a photograph was taken of every plate jacket to capture standard plate information and additional notations that may have been made by observers or researchers

Plate Annotation Photographs

Many researchers made ink annotations on the rear of plates to identify objects. If such annotations were found prior to scanning, they were photographed and then the annotations were cleaned from the plate. The emulsion side of the plates was never cleaned.

Fitted Plate Scale

Average plate scale from available WCS fits in arc seconds per mm. This column can not be comprehensive because of the following anomalies:

• The mc series notably has two separate scales because the telescope was refigured after plate 3499. Plates subsequent to 4171 were taken with a curved plate holder.
• The mb series uses a different telescope between plates 2389 and 2721 inclusive.

These anomalies are currently hard-coded in the database access software.

Exposure Information

Many of the plates have multiple exposures to increase the dynamic range of the emulsion, include calibration fields, or look for short-period brightness changes. For each exposure, the Right Ascension and Declination are calculated for the center of the plate.

Geocentric and Heliocentric Dates

The time of the exposure is expressed as a geocentric date. The corresponding heliocentric date is calculated with reference to the right ascension and declination of the center of the plate. Since some plate series contain plates which cover wide areas of the sky, the heliocentric date may vary significantly from the value at the center of the plate. If the user specifies a specific location or object in the search page, then the Julian Date result will show the heliocentric date for that object in the search page results table.

Plate Center Source and Date Source

The initial digitization effort involved typing in the card catalog for the stacks. Approximately 129,000 catalog entries were digitized prior to the availability of initial results from the plate scanner. At this point, the scanner results showed that the Julian Date information available in the card catalog was not of sufficient accuracy for the discovery of objects such as eclipsing binaries. The decision was then made to photograph and digitize the logbooks which were the source of the card catalog data. Information from the card catalog is still designated as Catalog and this information will be eventually replaced by information from the logbooks which are designated by Logbook. Because the logbook plate centers have a median error of about 0.5 degrees, these logbook plate centers will eventually be replaced with the results of wcs fitting to star catalogs which are designated by imWCS or WCS. For the source of the exposure time, only Catalog and Logbook apply.

Exposure Notes

The digitized card catalog information contains a remarks field which is preserved in the database.

Time Accuracy

There are a number of automated checks possible on the digitized logbook data. The results of these checks is a time accuracy estimate to give researchers an indication of the reliability of the quoted time. Time accuracy is not available for catalog entries.

Logbook Information

The database contains images of 663 bound logbook volumes and approximately 500 loose leaf logbooks. Some of the data has been digitized at Harvard and in India, but currently the data is being digitized by volunteers at the American Museum of Natural History in New York City. We appreciate the assistance of Dr Michael Shara, Curator, Dept. of Astrophysics, Holly Klug, Supervisor of Explainer Programs, Dept. of Volunteer Services and their team of volunteers. All of these photographs are available for browsing.

Exposure Start and Stop Times

Exposure start and stop times were generally recorded in Local Sidereal Time, but in some cases Eastern Standard Time or Universal Time was used. The time type in use can usually be determined from the plate center right ascension and the hour angle. The final reported exposure time in the plate exposure information table is the average of the start and stop times. These times are given to a varying number of significant digits and are used to initialze the time accuracy entry.

Hour Angle

The hour angle was reported not only in the standard sense of increasing time West of the meridian, but sometimes the opposite. Occasionally errors in the sign of the angle can be detected from the context of the rest of the observation.

Logbook Remark

Because comments entered into the logbooks have no defined formats, the typists were instructed to enter either Y or N. If this field is blank, the logbook entry has not yet been processed. This field is deprecated.

Logbook Notes

Entries are usually entered at Harvard for certain targets of opportunity. These notes contain the reason for transcription.

Errors Detected by Automated Checks

A number of automatic checks of the logbook data is possible. If one of these checks fail, then the reported time accuracy is reduced accordingly or simply set to 1 day if the actual error magnitude is not obvious. The following definition list shows the error check flags that appear in the database should one of these tests fail. The versions referred to below are used to differentiate new logbook data being entered into the database from previously existing logbook data.

Error Code	Description
Discrepancy	Discrepancy between India and Cambridge transcriptions. (Deprecated because of exposure number uncertainty for multiple exposures)
E vs W Fixed	E Hour angle mistaken for W or vice-versa. Automatically corrected
Bad Date Fixed	Bad date fixed from nearby data (Not yet implemented)
Bad Date	Bad date which has not been corrected
12H Fixed	12 Hour LST error Fixed
Exposure Times Disagree	Exposure Times Disagree
Non-Numeric Exposure	Non-numeric exposure time
Daylight Exposure	Exposure while sun is up
Bad Volume Number	Volume numbers disagree
HA not LST minus RA	Error in Hour Angle
Field Length Exceeded	Field Length Exceeded
Bad Remark	Remark field not "Y" or "N", corrected to "N"
Bad Multiple (OLD)	Multiple exposures on different pages - compared with old version
Bad Multiple (NEW)	Multiple exposures on different pages - compared with current version
Decreasing plateNumber	Plate number not monotonically increasing
Unknown Time Type	Unable to determine if time is LST, UT, or EST because longitide is missing
Below Horizon	The telescope is apparently pointing below the horizon
Bad Page	Error decoding the logbook volume and page
Bad Time Type	Best type type is not the expected time type
Unrecognized Time Type	Can not decode the time type in the transcription
Unexpected Time Type	Transcription time type disagrees with the ranges table
Bad RA	Right Ascension less than 0 hours or greater than 24 hours. NOTE: In some cases, the Right Ascension was deliberately written greater than 24 hours. For these cases, 24 hours should be subtracted from the Right Ascension.
Bad Declination	Declination less than -90 degrees or greater than +90 degrees. Note: In some cases, the Declination was deliberately written greater than 90 degrees or less than 90 degrees. For these cases, subtract positive declinations from 180 and negative declinations from -180 and add 12H to the hour angle.

Scan and Mosaic Information

Scan Number If a plate is scanned multiple times, the scan number keeps track of individual scans.

Mosaic Number

If a second mosaic must be created from a single scan using a new mosaic algorithm, the mosaic number identifies the algorithm. If available, a new mosaic number is assigned with the corresponding scan number. If not available, new mosaic numbers are assigned from unused scan and mosaic numbers. Afterwards, a new scan number will not be assigned an existing scan or mosaic number.

Scan Date

The scan date is important for identifying early scans which are likely to be of lower quality while the scanner was being tested. Because of the mutually exclusive means of assigning scan and mosaic numbers, the scan date is a better way to determine the order of scanning.

Average Tile ADU

Tiles are individual exposures of the scanner camera which are later combined into a mosaic. Since the scanner camera has a 12 bit CCD readout, the average tile ADU will range from the bias level of 50 ADU to the maximum level of 4095 ADU.

Average and Maximum Tile Saturation

In order to improve the dynamic range for dark plates, the scanner exposure time is automatically adjusted. However, pixels imaging film defects and other areas of missing emulsion will saturate. The saturation count is the number of pixels at 4095 ADU on a per tile basis. Since there are 16M pixels per exposure, this is the upper limit of saturation.

Scan Comment

If the average and maximum tile saturation levels reach preset amounts, the scanner software will automatically enter Saturation Error in this field. The scanner operator is free to add any additional comments describing the state of the plate or the reason for the scan.

Mosaic Comment

If a special issue arises with the creation of the mosaic, a comment will be entered here. Currently, the only comment for some mosaics is Linearity Bug which means that the mosaic should be rejected because of a bug in the early version of the mosaic algorithm.

Mosaic Binning

Normally, the mosaic algorithm generates two mosaics simultaneously. These are the full size mosaics with 1 in this field and a 16 x 16 binned mosaic with 16 in this field. Some other binning factors for early mosaics are also present, but the binning factor must be a power of two.

WCS Fit Solution

This entry indicates whether the stars on a mosaic have been fitted to a standard catalog so that an accurate plate center is known.

Mosaic Rotation

If a WCS fit solution is available, this entry indicates how much the original mosaic must be rotated in a clockwise direction so that North is up.

Photometry Pipeline Information

Plotting Symbols

The following plotting symbols are used. These symbols are defined for the WIP Plotting Software Package. The plotting codes appear in the flags database column listed above.

Symbol	Plotting Code	Description
Solid circle	17	for a good point
Small solid circle	17.5	for a good point at the edge of the plate
Open circle	22	for a large error point
Small open circle	22.5	for a large error point at the edge of the plate
Arrow pointing down	31	for not found at the indicated limiting magnitude
Small arrow pointing down	31.5	for not found at the edge of the plate
Asterisk	3	for a suspected plate defect
Triangle	7	for a high astrometric error object
Open square	6	for a Pickering Wedge object
Solid square	16	for an object with high or unknown extinction
Arrow pointing up	30	for an object too bright for the photometric algorithm
Diamond	11.5	for a blended object
Cusped square	10.5	for a high local correction object
Letter b	98.5	for an object considered blended by sextractor, but not by the pipeline because of the low threshold we used in running sextractor
Letter c	99.5	for a good object without color correction
Letter q	13.5	for a good object in a plate with: multiple exposures, gratings, red or yellow filters, Pickering Wedge, spectra, fails colorterm metropolis algorithm, or fails colorterm limits.

AFLAGS

This field is a bitmap of fatal photometry pipeline errors which exclude a magnitude measurement from being included in the summary statistics for a star. Bits 16-18 come from the GSC2.3.2 class field, but only the code for a non-star is currently defined. Bits 20-23 are cases of blended stars. A case B blend is a single image that covers multiple GSC2.3.2 stars. A case C blend is a single GSC2.3.2 star that can be matched to multiple images. A case D blend is multiple GSC2.3.2 stars matching multiple images. Processing of this blend involves subdividing it into smaller groups of matches with the above blend designations: i.e. DA, DB, and DC. The showflags utility can decode the AFLAGS field into its constituent bits.

Bit Position	Decimal Value	Hexadecimal Value	Description
7	128	80	Plate fails quality criterion
8	256	100	Unmatched object on a multiple-exposure plate
9	512	200	Object has an uncertain date for extinction calculation
10	1024	400	Object is a multiple exposure blend
11	2048	800	Maximum isophotonic rms exceeded
12	4096	1000	Maximum locally smoothed rms exceeded
13	8192	2000	Star too close to the limiting magnitude
14	16384	4000	Star is in bin 9
15	32768	8000	Object rejected because bin has unknown drad.
16-18	65536	10000	Galaxy (not in GSC 2.3.2)
16-18	131072	20000	Blend (not in GSC 2.3.2)
16-18	196608	30000	Object is Non-star
16-18	262144	40000	Unclassified (not in GSC 2.3.2)
16-18	327680	50000	Defect (not in GSC 2.3.2)
16-18	458752	70000	Duplicate Star (Added for DASCH project)
19	524288	80000	Variable
20	1048576	100000	Case B - blended
21	2097152	200000	Case C - overlapping Sextractor hits for one GSC star
22	4194304	400000	Case D - mixture of cases B and C
23	8388608	800000	Object has a drad three times the bin drad or is in a bad spatial bin or local bin
24	16777216	1000000	Object is a Pickering Wedge object
25	33554432	2000000	Object fails the defect filter
26	67108864	4000000	Copy of the Sextractor blended flag
27	134217728	8000000	Rejected blended object - avoid plotting a limiting magnitude.
28	268435456	10000000	Rejected because of high smoothing correction
29	536870912	20000000	Object is too bright for accurate magnitudes
30	1073741824	40000000	Object is within 23.5 degrees of horizon

BFLAGS

This field is a bitmap of non-fatal photometry pipeline conditions which provide additional information concerning how the image was processed. Bits 12-15 are GSC2.3.2 magnitude substitution flags which depend on the setting of bit 23. The showflags utility can decode the BFLAGS field into its constituent bits. Note that bits 12-15 now contain the definitions defined in MAGFlags below.

Bit Position	Decimal Value	Hexadecimal Value	Description
0	1	1	Object has neighbors
1	2	2	Object was blended with another
2	4	4	At least one pixel is saturated
3	8	8	Object is too close to the image boundary
4	16	10	Object aperture data incomplete or corrupted
5	32	20	Object isophotal data incomplete or corrupted
6	64	40	Memory overflow during deblending
7	128	80	Memory overflow during extraction
8	256	100	Magnitude adjusted for a blended star (currently unused)
9	512	200	Object has low drad but it is in a high drad bin (currently unused)
10	1024	400	Object PSF considered saturated (ISO5/ISO4 > 0.7) and ((BACKGROUND+FLUX_MAX) > 7500)
11	2048	800	Magnitude-dependent calibration has been applied.
12	4096	1000	JMag substituted for JpgMag (deprecated)
13	8192	2000	BMag substituted for JpgMag (deprecated)
14	16384	4000	RMag substituted for FpgMag (deprecated)
15	32768	8000	VMag substituted for FpgMag (deprecated)
16	65536	10000	Good star processed by the pipeline
17	131072	20000	Star has been calibrated with the lowess fit
18	262144	40000	Star has been locally calibrated
19	524288	80000	Magnitude has been corrected for extinction
20	1048576	100000	Magnitude calibration not possible because the star is too bright
21	2097152	200000	Bin has a valid color correction
22	4194304	400000	Color correction used the metropolis algorighm
23	8388608	800000	Interpret bits 12-15 as Kepler Input Catalog Source bits;
27	134217728	8000000	Spatial bin fails QUALITY_COLORTERM
28	268435456	10000000	Ra and dec have been adjusted by the bin medians
29	536870912	20000000	This plate has an uncertain Julian Date
30	1073741824	40000000	Catalog position corrected for proper motion

FitWCS

This field is a bitmap of status flags which summarize the state of pipeline processing for the mosaic.

Name	Decimal Value	Description
Selected	1	Selected for fitting
MikeShawFit	2	Previously fitted by Mike Shaw (deprecated)
Completed	4	Fitting process successful
Copied	8	Fit results copied to head cluster (deprecated)
MultFailedAstrometry	16	Fit results failed AstrometryWCS for next exposure
MultFailedSeparation	32	Fit results failed the separation criteria for the next exposure
MultSucceeded	64	Fit results succeeded for the next exposure
StaleSolution	128	Better astrometry invalidates this solution
StaleExposureNumber	256	The exposure number of this solution has been changed
Wedge	512	This is a Pickering Wedge plate
FilterBlendedTimeout	1024	The filterblended routine timed out
NoAllObjects	2048	The allobjects file for this solution is missing
DuplicateREFCount	4096	This solution shares the same stars with a previous solution
ColortermCrash	8192	The colorterm.m script has crashed and needs to be rerun
InaccuratePV	16384	The SCAMP polynomial fit has significant inaccuracy
NoneFile	32768	The {}_none.db file produced by filter_multiple is present. NOTE: this entry is an internal software flag that does not appear in database files.

MAGFlag

This variable contains flags used in the processing of the GSC2.3.2 catalog. These flags are necessary because the GSC2.3.2 catalog contains magnitudes from multiple source catalogs which used different color filters. Furthermore, there are bugs in the GSC2.3.2 catalog which generate multiple entries for certain bright sources. The goal to put all of the GSC2.3.2 objects on a single color system became possible with the availability of the Kepler Input Catalog. Initially, bits 1-4 were used to identify simple substitutions of JMag or BMag for an unavailable JpgMAG; and RMag or VMag for an unavailable FpgMAG. These definitions are now deprecated. Bits 5-6 are used to eliminate duplicate references to a star and then cleared once this goal has been accomplished. When the Kepler Input Catalog became available, color transformations are now used to put all of the six different populations in the GSC2.3.2 catalog into the reference system of the Kepler Input Catalog and then into the JpgMAG/FpgMAG reference system of the majority of GSC2.3.2 stars. The labels beginning with COLOR identify these six populations. These labels were chosen so as not to create a conflict with the older definitions during pipeline processing. For the Kepler Input Catalog, definitions preceded by KEPLER_CQ designate the source of the Kepler catalog object. This variable is currently unused for the .

Label	Bit	Decimal Value	Hexadecimal Value	Description
COLOR_JPGMAG_FPGMAG	x	0	0	No substitutions
COLOR_BMAG_FOR_JPGMAG	x	3	3	BMag substituted for JpgMag
COLOR_VMAG_FOR_FPGMAG	x	4	4	VMag substituted for FpgMag
COLOR_VMAG_BMAG_FOR_JPGMAG_FPGMAG	x	5	5	BMag substituted for JpgMag and VMag substituted for FpgMag
COLOR_TYCHO	x	6	6	This is a Tycho Source
COLOR_SKYMAP	x	7	7	This is a Skymap Source
JMAG_FOR_JPGMAG	1	1	1	JMag substituted for JpgMag (deprecated)
BMAG_FOR_JPGMAG	2	2	2	BMag substituted for JpgMag (deprecated)
RMAG_FOR_FPGMAG	3	4	4	RMag substituted for FpgMag (deprecated)
VMAG_FOR_FPGMAG	4	8	8	VMag substituted for FpgMag (deprecated)
SAME_LOCATION	5	16	10	Rejected because location (RA and DEC) is identical (INTERNAL)
SAME_ENTRY	6	32	20	Rejected because all fields are identical. (INTERNAL)
DUPLICATE_PAIR	7	64	40	Part of a pair of location identical objects. Reject only objects with bit 6 set (INTERNAL)
TYCHO_SOURCE	8	128	80	This is a Tycho source (INTERNAL)
SKYMAP_SOURCE	9	256	100	This is a Skymap source (INTERNAL)
KEPLER_CQ_SCP		0		Kepler Catalog Source, valid when BFLAGS bit 23 is set
KEPLER_CQ_2MASS		1		Kepler Catalog Source, valid when BFLAGS bit 23 is set
KEPLER_CQ_PHOTO		2		Kepler Catalog Source, valid when BFLAGS bit 23 is set
KEPLER_CQ_TYBV		3		Kepler Catalog Source, valid when BFLAGS bit 23 is set
KEPLER_CQ_UNCAL		4		Kepler Catalog Source, valid when BFLAGS bit 23 is set
KEPLER_CQ_NOCAL		5		Kepler Catalog Source, valid when BFLAGS bit 23 is set

quality

On December 11, 2009, Sumin Tang made the following request to eliminate common causes of outliers in her search for interesting variables: Only use the very good points AND(not blends, not defects, not high drad, not within 23.5 degrees of horizon, not in bin 9, not within 0.5 mag to the limiting magnitude, not high iso rms, not high local smoothing rms, not pickering wedge object) in good blue plates AND(colorterm between -0.5 and 0.25 in the bin, colorflag==2, not dny plates, not dnr plates, not multiple exposures, not pickering wedge plates) for the calculation of min_local, max_local, range_local, min_local2, max_local2, range_local2, median_local, rms_local, ngood, clip_median_local, clip_rms_local, clip_ngood, median_iso, range_iso in the ID table. For individual images, most of these conditions are handled by selecting only magntiudes with AFLAGS equal to zero. The remaining conditions are handled by this plate quality flag which marks plates that are second quality. Note that the colorterm flag does not appear in the database because this condition is dependent on the annular_bin that the image appears in. The colorterm limits were shifted to -0.067 to 0.283 when the recalibrated GSC2.3.2 catalog was introduced in January, 2010. These new colorterm limits represent the 5% and 95% tails of the new colorterm distribution for blue plates in the M44 region.

Name	Decimal Value	Description
multiple	1	Multiple exposure
grating	2	Grating exposure
color	4	Color filter used
colorterm	8	Fails colorterm limits (unused)
wedge	16	Pickering Wedge plate
spectra	32	Spectra plate

REFNumber

In order to reduce disk space, GSC2.3.2, Kepler, APASS, and DASCH designations were replaced with a sixty-four bit integer. To convert from the catalog reference (REF) to the integer (REFNumber), the following rules apply:

Catalog	Conversion
Unmatched objects	Replace NONEwith 0
GSC2.3.2	Replace N with 11 and S with 12. Be sure to retain any leading zeroes in the numeric part of the GSC2.3.2 identification.
Kepler Input Catalog	Replace K with 2
DASCH	DASCH and APASS designations are similar to SDSS designations which are based on Right Ascension and declination. DASCH Jhhmmss.sSddmmss becomes 3hhmmsssSddmmss where S is 1 for positive declination and 2 for negative declination. For example, DASCH J083039.3+140709 becomes 308303931140709. The only difference with APASS designations is that a 4 prefix replaces the 3 prefix.

rejectFlag

These flags are set whenever the collection of images in the local bin do not meet overall quality requirements for the local bin. Such flagged images are not used in statistical analyses.

Name	Decimal Value	Description
DMAG_REJECT_HIZOUT	1	local correction bin rejected because the local correction is out of range
DMAG_REJECT_MEDIAN	2	local correction bin rejected because median brightness dimmer than the limiting magnitude
DMAG_REJECT_DRAD	4	local correction bin rejected because majority of stars have high drad

reject_reason

The lightcurve plotter compiles summaries of the reasons why individual magntiude measurements should be rejected from consideration. These flags are compiled mostly from AFLAGS with some additional error conditions.

Bit Name	Bit Position	Decimal Value	Hexadecimal Value	Description
ERROR	0	1	1	Error processing this Plate
OFFPLATE	1	2	2	Object not on plate
BINFAILURE	2	4	4	No data for this spatial bin
UNDETECTED	3	8	8	Object undetected on this plate
WEDGE	4	16	10	Object is a pickering wedge
DRAD	5	32	20	Object has high DRAD
DEFECT	6	64	40	Object failed the defect filter
HIZOUT	7	128	80	Object in bad spatial bin
BLEND_NOMATCH	8	256	100	Object in glare of brighter object
BLEND	9	512	200	Object is blended
BIN9	10	1024	400	Object is in bin 9
LOCAL_RMS	11	2048	800	Object has high locally calibrated RMS
LIMITING_MAG	12	4096	1000	Object within 0.5 mag of the limiting magnitude
TOO_BRIGHT	13	8192	2000	Object is too bright
LOW_ALTITUDE	14	16384	4000	Object is too close to the horizon
ISO_RMS	15	32768	8000	Object has high lowess RMS
DRADBIN	16	131072	20000	Object is in a bin with too high RMS drad
COMPLEX_BLEND	17	262144	40000	Object has a case c or d blend
MULTIPLE_BLEND	18	524288	80000	Object is a multiple blend
UNCERTAIN_DATE	19	1048576	100000	Object has an uncertain date for extinction calculation
MULTIPLE_NONE	20	2097152	200000	Unmatched object on a multiple exposure plate
QUALITY	21	4194304	400000	Plate fails quality criterion - see quality

fatalError

These error codes are generated by the CheckProgress routine which is used to ensure completeness when the pipeline is rerun for all plates because of major revisions. Codes less than 100 indicate completed execution. Codes between 99 and 1000 indicate incomplete execution. Codes greater than or equal to 999 are software consistency checks.

Name	Decimal Value	Description
FATAL_NO_MATCHFILE	1	No match file found
FATAL_NO_ALLOBJECTS	2	recover_points failed
FATAL_ASTROMETRY	3	find_astrometry2 failed
FATAL_ASTROMETRY2	4	find_astrometry2 failed. None file does not exist
FATAL_MAX_SOLUTION	5	Too many solutions
FATAL_ASTROMETRYWCS_FAIL	6	AstrometryWCS failed
FATAL_MULT_FAILED_SEPARATION	7	Second solution is too close to the first
FATAL_MISSING_ALLOBJECTS	8	Allobjects missing for higher order solution
FATAL_NO_FILTER_MULTIPLE	100	filter_multiple did not run
FATAL_NO_ASTROMETRY	200	find_astrometry2 did not run
FATAL_STALE_FILTER_MULTIPLE	300	Latest summary allobjects file not later than individual solution allobject file
FATAL_NO_SUMMARY_ALLOBJECTS	400	Summary allobjects file does not exist
FATAL_NO_WCSHISTORY	500	No AstrometryWCS history available
FATAL_STALE_ALLOBJECTS	600	Allobjects stale for higher order solution - run filter_multiple
FATAL_STALE_ALLOBJECTS2	700	Allobjects stale for higher order solution - run rest of pipeline
FATAL_MISSING_MATCHFILE	800	matchfile missing for higher order solution
FATAL_STALE_MATCHFILE	900	stale matchfile for higher order solution
FATAL_NO_NEXT_MOSAIC	10000	MULTSUCCEEDED without a mosaic
FATAL_UNKNOWN_MOSAIC_STATE	20000	Unknown mosaic state
FATAL_NO_LAST_MOSAIC	30000	Could not get the last mosaic
FATAL_ORPHAN_NEXT_MOSAIC	40000	Have next mosaic but no astromfithistory
FATAL_ORPHAN_NEXT_MOSAIC2	50000	Have next mosaic but no find_astrometry
FATAL_ORPHAN_NEXT_MOSAIC3	60000	Have next mosaic but no none file
FATAL_ORPHAN_LAST_SUCCESS	70000	Have successful next mosaic but no astromfithistory
FATAL_ORPHAN_LAST_SUCCESS2	80000	Have successful next mosaic but no find_astrometry
FATAL_ORPHAN_LAST_SUCCESS3	90000	Have successful next mosaic but no none file
FATAL_ORPHAN_GOOD_ASTROMFITHISTORY	100000	Have good astromfithistory but no find_astrometry
FATAL_ORPHAN_GOOD_ASTROMFITHISTORY2	110000	Have good astromfithistory but no none file
FATAL_ORPHAN_SUCCESS_FILE	120000	Have an astrometry success file, but no none file

magcal_local_rms

This is the estimated error of the locally corrected magnitude measurement. Since adding the spatial bin rms and local correction bin rms in quadrature produces errors which are higher than the rms of the final lightcurve for constant stars, the following procedure recalculates the error based on stars of similar magnitude in the spatial bin.

1. For each spatial bin, take all of the images which have successfully completed local calibration and sort them by magcal_magdep, the locally corrected and magnitude-dependent corrected magnitude.
2. After sorting, divide the images into magnitude bins with 20 stars per bin. Within each bin find the 3-sigma clipped rms of (magcal_magdep - Stdmag) where Stdmag is the catalog magnitude adjusted by extinction. Since the mean and median values of this rms are expected to be zero, the rms calculation is zero-based rather than based on the mean.
3. For every image within the spatial bin and magnitude bin, use the rms calculated in step 2. Images dimmer the limiting magnitude will have the rms set to 99.0 and images brighter than the brightest magnitude will use the rms of the brightest magnitude bin.