INCOMPATIBLE FILTER AND DATABASE PASSBAND
Stacking program, astrometric (plate) solver, fits file viewer
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I have been using monochrome CCD images taken with an IR passband filter. The fits header contains: FILTER = 'No filter'. So essentially this is a 'visual' observation. I guess there will be quite a number of observers who image without a filter or a so-called 'clear' filter to protect the CCD chip.
After running photometry the graphics of the AAVSO report shows magnitude values but the photometry table lists all observations as "INCOMPATIBLE FILTER AND DATABASE PASSBAND".
What should be written as 'Filter' in the fits header in order to make regular photometry possible?
Thanks for help and cs
Axel
The "Nan" is for the measured variable magnitude, Which star database did you select? I will check this afternoon how this condition can occur.
Han
If the filter was blank it would have selected CV. "No filter" is for a program difficult to understand.
In the report window the filter in the header can be overriden. But that is after the measurement. This is fine if you select the correct comparison star database in advance. But there the choice is limited. So V, B, R and SG, SR, SI.
As soon you select Gaia SI as reference database a few reference stars will have a SI magnitude and will be annotated accordingly. But Si is not the same as your your filter (I assume)
So how to we get a reference magnitude for your observation? And how does it match with the AAVSO filters?
https://www.aavso.org/filters?check_logged_in=1
Alternative would be to report pure instrumental magnitudes
For the moment I think it is better to remove the filter selection from the report. It was intended for users without a filter wheel. But you can also update the filter name in the files with the popup menu.
Han
Han,
I should have looked up first the available filter codes in the manual, sorry.
I have updated the FILTER keyword of the files with 'CV' and after running a manual star selection I receive a warning that 'documented COMP magnitudes for this filter could not be retrieved'. I guess the lack of a filter is the problem here? How could I retrieve instrumental magnitudes (which would be ok for just finding the time of maximum light)? There is also a note to use Gaia BP which however was already selected.
Running with V50 works fine .
cs Axel
Hi Axel,
I have removed the manual setting of the filter in the report window because it made it all to complicated.
So the procedure should be as follows:
1) Select all files in the photometry tab and call op the popup menu in the file list. Select "change header keyword" then enter "filter" and then the filter-name you want to add to the files.
2) Select Measure all AAVSO stars.
3) Press play button
4) Select var, one comparison star and one check star.
Then the star database is irrelevant because all measurements are related to the comparison star magnitude. So all values are then instrumental. You will not have that with an ensemble. Then the magnitudes must be absolute. The only problem is to find one comparison star with a know documented magnitude for your filter to do differential photometry.
Cheers, Han
I just installed ASTAP 25.3.03 and in the AAVSO form I noticed a dropdown box that contains a CCD/DSLR/PEP list. What is it for?
I have been checking my DSLR files and noticed that all FILTER entries are set to 'Green'. ASTAP appears to recognize that as well so that might be worth to mention that in the manual like 'V or G or TG or Green'.
cs Axel
Han,
could you please describe what the CCD/DSLR/PEP list on the AAVSO report form is for?
Thanks Axel
Yes. I should update the manual. This has to wait some time. I currently just too busy with other things.
In the past I ASTAP always reported CCD, but a user brought to my attention that also DSLR is possible. See below
Cheers, Han
https://www.aavso.org/aavso-extended-file-format
Thanks for the information. So it's just an entry for the AAVSO report. I thought it might have to do something with data reduction.
cs Axel
Yes.
Please upgrade to ASTAP version 2025.03.07. The previous version has a bug in sigma clip stacking of OSC images.
Cheers, Han
Just subscribed to sourceforge so I am automatically notified when you release a new version :-) Thanks for all your efforts!
cs Axel
Han,
I am currently preparing a report for the Journal (Rundbrief) of the German Variable Stars Association BAV about the latest changes in ASTAP. I noticed that after running a manual star selection the AAVSO report form is still labelled 'Measure all mode' rather than 'Manual Selection mode'. This might be confusing for a user. Is this just a mistake or by design? Thanks for your answer!
cs Axel
Hi Axel,
Yes the message is created when AAVSO report window is openend/created. It is not updated when you leave the AAVSO report window open. I will remove the message and release a new development version. I will add also a marker if you select manually a saturated star.
Cheers, Han
Done in development version 2025.03.17
http://www.hnsky.org/astap_setup.exe
The next two weeks I will have less time for programming.
Han,
How does this marker look like? I have a star field where some stars are saturated but I did not notice special marker after running a manual selection.
It would also be helpful if the markers in the image could somehow be linked to the comp list in the AAVSO report form. If non-AAVSO stars are selected it it time consuming to identify which star belongs to which entry in the comp list. Maybe a number related to the position in the comp list would do.
cs Axel
It just adds the word saturated. See attached. Busy here. In a week I will have much more time.
Cheers, Han