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 Mosaic (not the coordinates of the targets or the Chandra), based on the overlay of Mosaic on ACIS. NO MORE OFFSET IS NEEDED. Pri is the priority. The plan is to observe 2.5 fields per night. The observation of CTB-109Lobe has to be split into two nights.
Champlane KPNO 4m/Mosaic Target Field list, January 11-12, 2005
Telescope pointing
Center of Mosaic Chandra
Pri Field RA Dec (J2000) l b ObsID Instru Exp NH/e22 Av
--- --------- ----------- ----------- --------- -------- ----- ------ ----- ----- -----
1 CTB-109Lobe 23 02 18.85 +58 54 40.1 109.23905 -1.02858 4626 ACIS-I 80.00 1.149 6.420
2 Maffei1 02 36 49.80 +59 36 19.0 135.90926 -0.58435 5619 ACIS-S 60.00 0.677 3.781 unobserved
4 PSR0355+54 03 59 19.37 +54 15 43.9 148.21037 0.88325 4657 ACIS-S 70.00 1.084 6.053
5 CXOUJ061705 06 16 36.40 +22 19 24.3 189.20474 2.78323 5531 ACIS-S 38.00 1.047 5.850 unobserved
3 OH231.8+4.2 07 42 01.49 -14 45 18.0 231.84038 4.14583 3765 ACIS-S 50.00 0.950 5.309
Click a object name to see the Mosaic and ACIS overlay on DSS image.
This should help to identify the field. Note that the DDS images are
E-left & N-up. But the Mosaic images at KPNO 4-m are E-down & N-left.
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 300 7.6 38.0 43.7
Ha dither 1x5 1200 22.6 113.0 156.7
V single image 2 2.6 2.6 159.3
V dither 1x3 240 6.6 19.8 179.1
I single image 2 2.6 2.6 181.7
I dither 1x3 240 6.6 19.8 201.5
------------------------------------------------------
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.
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Object: GRS1227+025 (=possible highly variable hard X-ray source first discovered with SIGMA in 1991 and likely confirmed on one of our EXITE2 balloon flights in 1997 -- an ApJ paper on all this is in press...). This object is about 20arcmin NE of 3C273, so 3C273 will be out of the Mosaic field.
Here is a finding chart for GRS1227+025. There are two bright stars near the center of the chart:
Star RA Dec (J2000) V -------------------------------------------------------- The brightest star 12:30:10.528 +02:13:53.86 10.04 The second brightest 12:30:04.534 +02:14:06.65 11.96 --------------------------------------------------------
To avoid too much bleedings from the bright stars, put both of them in the gap between chips 6 and 7 of the Mosaic. So put the the following Coordinate in the Mosaic center:
Desired exposures: U,B,V,R,Ha to reach V~24
Goal: to find blue, and possibly VARIABLE, object in large (~10arcmin!) hard X-ray error box.
Strategy: If clear, do U,B,V,R,Ha exposures on BOTH nights. Following exposure sequence will reach mag~24 for B, V and R. But U and Ha will be much shallower. Do three dither positions in each filter (long exp.) for CR rejection. Ha exposures to reach equiv. mag. of say (only) ~21. to look for bright Ha objects (and to save time). B exposures at beginning and end to look for variability in B.
Exposure sequence: If the weather is photometric, do the following exposure sequence.
Exposure sequence for GRS1227+025
Filter Frame Exp Exp+readout Total Timeline
(sec) (min/frame) (min) (min)
------------------------------------------------------
B single image 2 2.6 2.6 2.6
B dither 1x3 300 7.6 22.8 25.4
U single image 2 2.6 2.6 28.0
U dither 1x3 300 7.6 22.8 50.8
V single image 2 2.6 2.6 53.4
V dither 1x3 300 7.6 22.8 76.2
R single image 2 2.6 2.6 78.8
R dither 1x3 300 7.6 22.8 101.6
Ha single image 30 3.1 3.1 104.7
Ha dither 1x3 300 7.6 22.8 127.5
B single image 300 7.6 7.6 135.1
------------------------------------------------------
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.
5. dither 1x3 is the following (mostly) E-W dither pattern to avoid
the two bright stars.
==================================================================
# Dither 3 positions for GRS1227+025.
# Offset relative to current telescope position
# RA (pixels) Dec (pixels)
0 0
100 -10
-100 10
==================================================================
This whole program would need about 2h15m exposure and readout time plus overhead.
If the weather is NON-photometric, just do variability sequence:
B (3 x 300sec), R (3 x 300sec), B(3 x 300sec), etc., etc.
to look for variable blue or red objects in this enormous error circle.
Date EVENING MORNING DURATION ------------------------------------------ 1/11 19: 7:36 6: 1:28 10:53:51 1/12 19: 8:22 6: 1:27 10:53: 5 ------------------------------------------Above exposure sequence requires 201.5 min (including readout time) for each field. 2.5 fields take 504min.
A. CTB-109Lobe can only be observed in the first 2.5 hours of the night. So its observatoin has to be split into two nights:
1. First night: Do all the exposures in the observing sequence except the long 1x5 dithered Ha exposures. This will take (201.5-113) 88.5min.
2. Second night: Take the long 1x5 dithered Ha exposures. This will take 113min. Before taking the long exposures, take one quick test exposure (with R filter and low resolution so it's quick to readout) to make sure the coord is correct.
B. In the first night, after spend the first 88.5min on CTB-109Lobe (see above), continue to do the full exposure sequence of Maffei1, then OH231.8+4.2. This will take a total of (88.5+201.5*2) 491.5min (not including the time to slew the telescope and enquire the field), i.e. 8h11.5m. This will end at around 3:19AM with the airmass of OH231.8+4.2 just under 2.
C. In the second night, after spend the first 113min on CTB-109Lobe (see above), continue to do the full exposure sequence of PSR0355+54, then CXOUJ061705. This will take a total of (113+201.5*2) 516min (not including the time to slew the telescope and enquire the field), i.e. 8h36m. This will end at 3:44AM with the airmass of CXOUJ061705 just under 2.
D. Do the GRS1227+025 after the Champlane fields are set.
E. The above Champlane target 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 198.9 min - a total saving of 27.6 min.
E. Try to start 10-15 min before the end of evening astronomical twilight to get a little more observing time.
F. Please use Atmospheric Dispersion Corrector (ADC) for the observation to remove the effects of atmospheric dispersion at high airmasses.
N Field ------------------- 1 CTB-109Lobe 2 Maffei1 3 PSR0355+54 4 CXOUJ061705 5 OH231.8+4.2 6 GRS1227+025 -------------------
postscript and
txt.
Here is an observing almanac made for this run.
Here
is the 2005 KPNO Observer's Almanac.
Night Do
Champlane targets Late night target
----------------------------------------------------------------------------------
1/11 CTB-109Lobe(all but 1x5 Ha) Maffei1 OH231.8+4.2 GRS1227+025
1/12 CTB-109Lobe(1x5 Ha) PSR0355+54 CXOUJ061705 GRS1227+025
----------------------------------------------------------------------------------
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 300 7.6 38.0 43.7
Ha dither 1x3 1500 27.6 82.8 126.5
V single image 2 2.6 2.6 129.1
V dither 1x3 240 6.6 19.8 148.9
I single image 2 2.6 2.6 151.5
I dither 1x3 240 6.6 19.8 171.3
------------------------------------------------------
A. First do CTB-109Lobe with the revised exposure sequence. This
will end at before 10PM with the airmass of CTB-109Lobe just under 2.
B. Then do the revised exposure sequence for Maffei1 and OH231.8+4.2 (2x171.3m=342.6m=5h42.6m). This will end at around 3:40AM with the airmass of OH231.8+4.2 around 2.
C. Do GRS1227+025 after B.
Night Do
Champlane targets Late night target
----------------------------------------------------------------------------------
1/12 CTB-109Lobe(all but 1x5 Ha) Maffei1 OH231.8+4.2 GRS1227+025
----------------------------------------------------------------------------------