AAVSO report CHART field
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Hi,
Does anyone know how in the ASTAP AAVSO report the coordinates (like' 201131.1+075125' for variable star V2013 Aql) are calculated?
I searched the ASTAP documentation, but it refers to the AAVSO extended file format:
- According to AAVSO this Chart field should be used for a chart code like 'X406151ID' or use comment code K for non-AAVSO chart. So I don't understand how this coordinate alternative works. Max 20 char, but they do not suggest to use coordinates instead.
- The value shown by ASTAP is not the position of the variable nor the center of the image, and it's not written in the FITS image file.
- It works, because the ASTAP output is obviously accepted by the AAVSO.
Thanks for clarifying
Tom
CHART: Please use the sequence ID you will find written in Bold print near the top of the photometry table in a sentence that reads "Report this sequence as [ID] in the chart field of your observation report." If you used your own comparison stars (e.g. in the case of time-sensitive alerts when the Sequence Team had no time to create a sequence), do not give a chart ID, even if you plotted the chart using VSP. Use the comment code K (non-AAVSO chart) and give a proper chart name like "APASS DR10". Then add information on the comp stars in the notes. Limit: 20 characters.
Hi Tom,
The variable position is according the AAVSO VSX: 20 11 34.49 +07 51 04.3. That matches to the coordinates you gave with a small offset. Proper motion is very small.
If the annotation is not available then ASTAP will report the measured star (Var, CNAME, KNAME) position as position label, in your case 201131.1+075125. So a substitute label for the AUID. Reporting is probably only possible if the label is used for CNAME or KNAME but not for the variable. The offset could be due to the image distortion or if it is a wide field a small error.
The chart number will be added to the report if you use the online database for annotation. Retrieving a chart label for the CNAME or KNAME stars is not possible. So only a positional label can be added as substitute for the missing AUID.
I assume that ASTAP did not match the star to a AUID or name cause it was not annotated. The star magnitude of the variable is around 13. Did you select the AAVSO annotation magnitude limit 15? If it doesn't work can you share one image? You could try to attach one image to your reply.
Cheers, Han
Last edit: han.k 2025-08-20
The label is in IAU style HHMMSS.s+DDMMSS
It's definitely not proper motion. The VSX position of the variable star is different by almost one arc minute. The label ' 201131.1+075125' also doesn't match the compstar used:
- CNAME = 'ENSEMBLE' as correctly shown in the ASTAP report.
- KNAME = AUID = 000-BMS-632 is what I used a comparison star (so '201105.2+074135')
I was hesitating to use the AAVSO chart label ('X40615ID') because the photometry is not based on APASS DR10, but on-line Gaia. AAVSO doesn't explain alternatives in this case, only allows up to 20 characters.
I didn't find a star in the image on the position label reported by ASTAP.
I did use online annotation up to mag 15
No problem to send an image, but they are 61 MB (32-bit fits) and probably too large to send here.
If I reduce them, the astrometric solution is lost, if 7-zipped, still 40 MB.
By the way: I see ASTAP is still using the FITS DATE-AVG field including download time from the ASI 6200 camera as reported by N.I.N.A. 3.1HF2. Maybe I should update my ASTAP version, or is there an option to use DATE-OBS + EXPOSURE/2 as midpoint time?
Regards,
Tom
(I add part of the ASTAP AAVSO report to show the result obtained)
It will be good to analyse the image. Upload it to this site:
https://ufile.io/
and send me the link.
You could remove the longitude & latitude for privacy reasons.
There has been several updates for photometry including a new local variable database but DATE-AVG is still preferential used. If missing ASTAP will use DATE-OBS + EXPOSURE/2. I remember vaguely this has been discussed, but I can't correct error in DATE-AVG if any. The program who produces it should write the correct value.
You should update from ASTAP, v2024.01.07 :)
I have uploaded one of the images as you indicated (site location is rounded):
https://ufile.io/99ful4ft
several AAVSO stars with AUID are available
000-BMS-632 (used as comparison star in KNAME)
000-BMS-634 (I did not use it, but maybe it's automatically included in the Gaia ensemble)
Tom
The image is proper solved since the star database annotation matches perfectly.
The variable position is according the AAVSO VSX: 20 11 34.49 +07 51 04.3.
Measured from your image 20: 11 34.48 + 7° 51 03.6 (Centroid) (without SIPS)
When I switch off the AAVSO annotation, I get for the variable 201134.5+077104. See attached In the current ASTAP version it is not possible to select individual stars as comparison /check star unless they have an annotation starting with 000-.
Rather then look back to the old version, it simpler to use the new ASTAP. The photometry has been significantly upgraded. So I would suggest you install the new ASTAP version. If the problem occurs again just tell me. Feedback is important and helps. Download also then new local variable database.
Windows program:
https://sourceforge.net/projects/astap-program/files/windows_installer/astap_setup.exe/download
Windows variable star database installer:
https://sourceforge.net/projects/astap-program/files/star_databases/variable_star_database.exe/download
Cheers, Han
Yes here are the links:
http://www.hnsky.org/astap_amd64.deb
or
http://www.hnsky.org/astap_amd64.tar.gz
ignore previous post. Posted at the wrong discussion
Today I have made a modification to add the IAU labelled stars also to the COMP & Check star list. This was missing because it wasn't reviewed for a long time. See this IAU style label as a temporary label to identify stars because there is no comparison and check star available.
I'm lost with the new version (2025.08.17) for photometry in Win 11:
- updated the version and the variable star database
- loaded calibrated images in the photometry tab
- ran analyze
- then selected proper gaia online options and other settings
- then double clicked on the first (or other) image to open in the viewing tab
- It no longer shows the familiar VAR/CHECK/3 option circles at all, so I cannot select anything
- The stacking tab cuts off setting option icons at upper right: 'AAVSO report' is almost off screen to the right, I can see only part of 'clear images' and cannot scroll any further right
Photometry first ran but couldn't make an AAVSO report because no VAR/CHECK/COMP selected but I got a very nice plot of the variable : looks much better than older ASTAP version.
Next time it complained no VAR/CHECK/COMP selected and didn't run, but I'm unable to select them in view mode (catch22). In previous versions these select circles appeared automatically at the upper left side of the viewed image.
How can you get the VAR/CHECK/COMP or 3 selection in the current ASTAP version ?
Are there more selection options in the stacking menu ? (they moved more to the right side)
Tom
(See attached screenshots)
Hi Tom,
Two settings you have to changed. See attached screenshot.
First select "Manual. star selection" Then you can click on up to ten stars. So more then one Comp and Variables * (The option you have now selected, will measure ALL stars automatically once you press the play button >|. Selection of the stars to measure is then done later in the report)
*
Secondly, you have selected for annotation "standard field" That is for measuring a "standard field" for transformation. Like M67, Mel111 cluseters. Std field accesses a different part of the AAVSO database and contains only stars for standard fields an no other stars so you see nothing in your image.
cs Han
Last edit: han.k 2025-08-22