• Target List
• Exposure Sequence
• Observation Plan
• Biases, Flats etc.

I. Target List

Following is the target list in the order of increasing RA. The RA and Dec in the list are the telescope pointings, i.e. the center of the MosaicII (not the coordinates of the targets or the Chandra), based on the overlay of Mosaic II on ACIS. NO MORE OFFSET IS NEEDED. N is the priority. The plan is to observe 3 fields per night.

                      Champlane KPNO 4m/Mosaic Target Field list, December 7-8, 2002

                     Telescope pointing
                     Center of Mosaic                                        Chandra Chandra
N  Field             RA           Dec (J2000)      glong       glat   NHe22  Instru     Exp
-  ----------------  -----------  -----------  ---------  ---------  ------  ------  ------
1  G116.9+0.2        23 59 12.53  +62 24  0.0  116.92520    0.13885  0.6700  ACIS-I   50.00
4  G127.1+0.5        01 28  0.00  +63 03 11.7  127.06168    0.47467  0.9380  ACIS-I   20.00
3  G166.0+4.2        05 27 12.06  +42 54  5.1  166.21545    4.36653  0.4880  ACIS-I   30.00
6  PSRJ0538+2817     05 38  0.54  +28 14 24.0  179.71080   -1.78683  0.6130  ACIS-S   20.00
5  MADDALENA'SCLOUD  06 49 24.78  -04 34  7.2  216.77166   -2.53118  0.8030  ACIS-I   30.00
2  M1-16             07 37 14.89  -09 41  7.6  226.82711    5.59390  0.3050  ACIS-S   50.00
-------------------------------------------------------------------------------------------

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II. Exposure Sequence

           Exposure sequence for each field

Filter  Frame         Exp   Exp+readout Total Timeline
                     (sec)  (min/frame) (min)   (min)
------------------------------------------------------
R       single image     2       2.6     2.6     2.6
Ha      single image    30       3.1     3.1     5.7
R       dither 1x5     240       6.6    33.0    38.7
Ha      dither 1x5    1500      27.6   138.0   176.7
V       single image     2       2.6     2.6   179.3
V       dither 1x3     180       5.6    16.8   196.1
I       single image     2       2.6     2.6   198.7
I       dither 1x3     180       5.6    16.8   215.5
------------------------------------------------------
1. Exp is the exposure time for each image in seconds.
2. Exp+readout is the exposure plus 2.6min readout time for each image.
3. Total is the total time ((Exp+readout) x dither) for each filter.
4. Timeline is the accumulated time for each field.

Under the Frame:
A. single image: take one short exposure filter.  No dither.   

B. dither 1x5: Use command "mosdither" to do one set of standard dither pattern 
   of 5 positions for R, Ha and V filters.  Take one image at each position. 
   The standard dither pattern is at "ditherdb$todd.dat".

It looks like this:
==================================================================
# Todd Boroson's canned dither scheme for the NOAO mosaic

        # Offset relative to current telescope position

        # RA (pixels)   Dec (pixels)

           0               0

         200            -200

        -200             200

         100             100

        -100            -100
==================================================================

C. dither 1x3: Use command "mosdither" to do one set of dither pattern of 3
   positions for V and I filters.  Take one image at each position.  
   Create a file at "ditherdb$dither3.dat" that looks like the
   following.  Then set the "mosdither" parameter: 

           offsets = ditherdb$dither3.dat

==================================================================
# Dither 3 positions.

# Offset relative to current telescope position

        # RA (pixels)   Dec (pixels)

           0               0

         200            -200

        -200             200
==================================================================

OR, simply use the standard dither pattern and stop it after 3 exposures.

III. Observation Plan

A. First of all, the above exposure sequence is the most time can be spent on each field. When time is running short, do the following to save time:

1. Skip V and I short (2 sec) images. (save 2.6 min each)

2. Reduce the number of I deep images, then V deep images. (save 5.6 min each) But keep at least one deep V and one deep I images.

After the above reduction, the total time needed for one field is reduced to 187.9 min - a total saving of 27.6 min.

B. Try to start 10-15 min before and finish 10-15 min after the astronomical twilight zone to get a little more observing time.

C. Don't need to take the standard (not enough time). We will apply for time on FLWO 1.2m telescope for the calibration.

N  Field 
-------------------
1  G116.9+0.2       
4  G127.1+0.5       
3  G166.0+4.2       
6  PSRJ0538+2817    
5  MADDALENA'SCLOUD 
2  M1-16            
-------------------

postscript and txt. Here is an observing almanac made for this run. Here is the 2002 KPNO Observer's Almanac.

Here is a suggested observation plan for the 2 nights.

Night                   Do
--------------------------------------------------------
12/7    G116.9+0.2      G166.0+4.2      M1-16
12/8    G127.1+0.5      PSRJ0538+2817   MADDALENA'SCLOUD
--------------------------------------------------------

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IV. Biases, Flats etc.

• Biases and Domeflats: Take biases and domeflats in the afternoon before dinner.
• Skyflats: Take twilight skyflats starting shortly after sunset at around 5:30pm.
• Pointing and Focus: Do telescope pointing and focus after the skyflats at around 6:10pm.

1. Biases and Domeflats

2. Skyflats

• Point the telescope to zenith at sunset - 5:26pm.
• Turn the tracking on during the skyflat exposures and turn the tracking off during the readouts so there will be a offset between exposures.
• Do the Ha filter skyflats first, then do the I filter skyflats.
• Start at about 5:30pm, take a 2 seconds Ha skyflats. Examine the image and make the adjustment of the exposure time so the flat has about 10000 counts.
• Take the first Ha skyflats with adjusted exposure time (remember to turn the tracking on during exposure and off during readout).
• Take the second Ha skyflats with exposure time twice as long as the first exposure (e.g.: first is 5sec, second one should be 10sec). The sky gets darker during the 2.6 min readout. To double the exposure time is just about to compensate the change in the sky.
• Take at least 3 Ha skyflats.
• If the exposure time is still under 30sec, continue to take the Ha skyflats until the the exposure time is over 30sec.
• Take the first I filter skyflat with exposure time equal to 1/10 of the last Ha skyflat exposure. Examine the image to make sure it gets about 10000 counts. Adjust exposure time if needed.
• Take the second I filter skyflat with exposure twice as long as the first.
• Take at least 3 I skyflats.

3. Pointing and Focus:

• Don't let the skyflats interfare with the observation. Stop at around 6:10pm and do the pointing and focus.
• try to start to observe the first ChaMplane field at around 6:30pm.

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