Tech time tasks for NOTCam

Comments to Amanda

If this is the first night NOTCam is mounted, then do all tasks described in First night tests.
Every clear/photometric night: JHKs zeropoint monitoring
If the seeing is good, check image quality: HR camera tests of image quality
If the weather is clear/photometric: Data still needed for the J band in order to model the illumination correction
If weather is clear/photometric: Check the vignetting of narrow-band filters
About once per year, and when the seeing is good (~ 0.5") make a Through-focus test .

JHKs zeropoint monitoring (WF)

On every NOTCam technical night which is clear/photometric, observe one of the below suggested standard fields at three different air masses in the range [1,2]. NOTCam imaging is done with the WF camera and the three filters JHKs. The instrument is setup correctly from the scripts, and target is acquired. You have to verify that autoguiding is achieved, and the rest is automatic. A finding chart should pop up on the screen, but no pointing adjustment should be needed in normal cases. The standard fields are found in the TCS catalogue /catalogue/notcamstd.cat but you don't need to load it, since the script will add and goto target.

Use the sequencer scripts whose names are given in the table. The scripts make a 5-point (dice) dither for each of the three filters Ks, J, and H, and adjusts the telescope focus accordingly per filter. The total time refers to the total time spent doing all three filters.


Field	FS	Other name	RA(J2000)	Dec(J2000)	K-mag	# stars	expmode	script	Tot time
AS05	6	Feige 22	02 30 17.5	05 16 25	13.4-13.5	2	frames 3.6 5	notcam.as05-jhk	11 min
AS16	14	Rub 149	07 24 15.4	-00 32 49	11.0-14.3	5	frames 3.6 3	notcam.as16-jhk	10 min
AS19	17	M67-IV-27	08 51 20.2	11 52 43	9.7-12.4	3	expose 4	notcam.as19-jhk	9 min
AS26	23	M3-VZ193	13 41 45.4	28 29 50	11.4-12.4	2	frames 3.6 3	notcam.as26-jhk	10 min
AS33	35	.	18 27 13.6	04 03 10	11.7-13.2	3	frames 3.6 3	notcam.as33-jhk	10 min
Ser-std	143	Ser-EC68,EC84	18 29 51.2	01 11 48	11-12.9	2	frames 3.6 5	notcam.serstd-jhk	12 min
AS40	.	NGC 7790	23 58 50.2	61 10 02	9.4-10.8	6	expose 4	notcam.as40-jhk	9 min

The designation FS stands for the UKIRT Faint Standards (see Leggett et al. 2006, MNRAS 373, 781-792 for references and JHK magnitudes.) Finding charts are obtained by clicking on the field name in the table. These K-band charts have North up and East left, the FOV is about 4' x 4', and they are taken from Hunt et al., 1998, AJ 115, 2594, except for Ser-EC68,EC84 which is a NOTCam image.

The field Ser-std contains the new red standards EC68 and EC84 (see Leggett et al. 2006, MNRAS 373, 781-792 with J-K colours from 3.57 to 3.99 magnitudes.

The visibility plot of today:

Minimum observing altitude when lower hatch closed: 35 degrees.

Please wait ... Generating visibility plot

To calculate the visibility plot for any date you can cut and paste the following table into the Staralt program.

as05 02 30 17.5 +05 16 20
as16 07 24 15.4 -00 32 47
as19 08 51 20.2 +11 52 43
as26 13 41 45.4 +28 29 50
as33 18 27 13.6 +04 03 10
ser  18 29 55.4 +01 13 11
as40 23 58 50.2 +61 10 02

HR camera test of image quality

If the seeing is good (fwhm < 0.6'' in the K-band), spend 15 min on image quality tests.

There is a NOTCam staff OB group in directory ~obs/scripts/54-901/ called hr_imqual

It consists of 5 OBs, one for each of the fields 1-5 below, and uses the HR-camera and the Ks (207) filter to run a 9-point dither three tiems. One OB script takes 900s. Select the best field.

field1 19:38:23.1 +11:59:25
field2 22:29:52.6 +55:24:33
field3 00:02:14.0 +67:25:00
field4 03:29:11.9 +31:22:51
field5 06:31:53.3 +04:56:35
field6 03:56:15.1 +53:52:12

Illumination correction data

A model of the illumination correction for the H-band has already been made by Joachim Janz and is published in Janz et al. 2013, submitted. We still need to take data in photometric conditions to map the J band. Do as follows:

Point to a field in the catalogue "notcamstd.cat" at airmass < 1.5. Use preferrably AS16, AS26 or AS33. Only if fwhm > 1.2'' can you use AS40.
Use the guide area called NOTCam-Be-NS (see Cookbook for how-to).
In directory ~/scripts/staff/amanda/ use the script "fov.script" which does a 5x5 dither with two exposures per position, each with the command ''frame 3.6 2''. The script takes ~ 1000s to run. Offset ~ 5'' randomly and repeat. Repeat as many times you can. We need about 15 times per filter, which can be distributed over several nights.

For the Ks band we have a total of 4 + 2 + 7 + 2 = 15 scans.
For the J band we have a total of 5 + 4 + 3 = 12 scans.

Vignetting of narrow-band filters

Check vignetting of narrow-band filters because of the fact that they are mounted tilted and in the parallel beam. Find a star with a strong emission line in e.g. Brackett gamma, for instance:

X-Per RA=03:55:23 DEC=31:02:45 (J2000) V=6.1mag

and scan the star across the FOV using the Br gamma narrow band filter (#209). Use a 5x5 dither. A script is found in ~scripts/staff/amanda/ and it is called fov.script, but you may have to adjust to a shorter exposure time than the "frame 4 8".

Through-focus test

Check the calibration and performance of the focus pyramid by running the script:

notcam.through-focus exptime

where exptime is the suitable exposure time for the focus star you have selected high in the sky (with no pyramid in the beam). For a typical exptime of 10 seconds, the whole script takes about 30 minutes. Alternating images are taken with the focus pyramid in and out scanning the focus range of +-150 units around initial guess-focus. The exptime is multiplied by 4 for the images taken through the focus pyramid. Make sure the instrument setup is correct before starting. Use Ks filter. Set the tcs.focus-position to your initial guess and tcs.focus-delta to zero.

Last modified: June 29 2023