Hi everyone,
I'm trying to use VPHOT to get some magnitude estimates for ASASSN-18dg. It is a faint target, and it does not show up automatically in VPHOT when I load target stars. So, I'm trying to create my own sequence by hand. After selecting the target and giving it its name, I selected a couple of comp stars (000-BPL-668 and 000-BPC-845) as well as a check star (000-BPL-669). After that, when I click "View Photometry Report", I am presented with the following error page:
Server Error in '/app' Application.
Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidOperationException: Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.
Source Error:
Line 352: stack = ex.InnerException.StackTrace Line 353: End If Line 354: MessageBox.Show(ex.Message & vbCrLf & vbCrLf & stack) Line 355: End Sub Line 356:
Source File: C:\projects\VphotGit\Logic\BL\Util.vb Line: 354
Stack Trace:
[InvalidOperationException: Showing a modal dialog box or form when the application is not running in UserInteractive mode is not a valid operation. Specify the ServiceNotification or DefaultDesktopOnly style to display a notification from a service application.] System.Windows.Forms.MessageBox.ShowCore(IWin32Window owner, String text, String caption, MessageBoxButtons buttons, MessageBoxIcon icon, MessageBoxDefaultButton defaultButton, MessageBoxOptions options, Boolean showHelp) +3221368 BL.Util.HandleError(Exception& ex) in C:\projects\VphotGit\Logic\BL\Util.vb:354 BL.Analysis.CreateSingleImageReport(FITSWrapper& FITS, Hashtable& activeMeasurements, Int32 selectedSequence, Int32 minSNR, Int32 searchRad, String chartID, Single aperture, Boolean transformed) in C:\projects\VphotGit\Logic\BL\Analysis.vb:293 SingleImageReport.CreateReport() +348 SingleImageReport.Page_Load(Object sender, EventArgs e) +1122 System.Web.UI.Control.OnLoad(EventArgs e) +97 System.Web.UI.Control.LoadRecursive() +61 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +693
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4110.0
I've also noticed that all the comp/check stars in my sequence disappear if I leave the page (even though I made sure to save the sequence). Any idea as to what is going on? VPHOT has been working fine for my other sequences.
Thanks,
jf
I've never seen this error before.
Please share the image and the sequence with SGEO and I will investigate
George
Thank you George,
I've shared my images and sequence with you. Please note that the stacked image is best visualized with levels set at low = ~20,000 and high = ~30,000.
Note also that these images are not calibrated, I need to re-take my darks tonight.
jf
Jean-Francois:
1. I'm making a guess from your use of the word 'faint' but take a look at the Tools>Settings and make sure that your
'Sequence file and catalog import
Only import stars with SNR > is something like 5 rather than 20+'.
2, After creating and saving your manual sequence, log out of vphot and log back in. See if the sequence appears. (This should not be necessary but try anyway.)
Ken
Thank you Ken, that's a great suggestion. Unfortunately, even after lowering the minimum SNR (I tried 5, then 3, then 1 and finally 0) I could not import comp stars. The target does get located automatically when I select "GCVS" in the 'catalog' menu.
The sequence does not disappear when I log out and log back in. However, the comp and check star which I manually add seem to randomly disappear when I go back to the images list and then back to the image.
jf
JF:
So you are now able to see the target on your images? What is the SNR and ADU for the target? What filter(s) are you using for the images?
There are several comps shown in the VSP. The brightest is 151. So why do you need to manually add comps? They should show up when you click load aavso comps under catalog?
I assume that each time you open an image, you do select your saved sequence and at least the target is identified with an aperture or a small red circle (unidentified)?
Edit: I guess the answer to these last questions is NO? The comps do not consistently show up? Could you also share images to MZK?
Ken
When I load the…
Ken,
When I load the stacked image and I choose 'GCVS' from the 'Catalog' menu, VPHOT finds my target and a bunch of other stars (30 targets and 57 comps). The SNR for the target is 17. I'm not sure exactly what you need for the ADU value, so here is a screenshot of the measurement details: https://photos.smugmug.com/photos/i-PdBq32N/0/692e196b/O/i-PdBq32N.png
This looked like a good start, but when I click on 'View Photometry Report', all the targets have a magnitude of zero (0.0). When I try to load AAVSO comp stars, I get an error message saying: "Comp stars/sequence exist, but none was imported due to no photometry for this particular filter, or too faint to be detected." and when I try to add comp stars by hand, the server send the error message (the one in my first message) every time I click the 'View Photometry Report' button.
I also shared the images and list with MZK.
Thanks again for your help and sorry for all the trouble.
jf
JF:
Sorry, I've never seen as many issues with a set of images. What software did you use to collect the images and process them?
I was able to load APASS comps. However, every APASS comp and most targets were saturated (gray aperture), (ADU>60,000 (?) in star profile), even though they were not very bright. What gain do you have listed in your processing software and in your VPhot telescope settings?
When comps do exist, the comp table at the bottom of the photometry page were probably not activated? Thus, all magnitudes were zero! If you click activate and then refresh, you will get target magnitudes. However, not sure I would trust them?
Between faint comps and saturated comps, I think no comps were found even though the FILTER=V, which is a standard filter.
Not sure this is going to be easy to fix?? Is this your first time processing images for vphot?
Ken
Good point about the gain setting! I actually did increase it up to 320 because the target is really faint (magnitude ~21) while I normally use gain zero (for bright targets) or 110 (which is just above unity gain).
Regarding the software, these were acquired with Kstars/Ekos. The only post-processing done was to plate-solve the files (with the offline astrometry.net program on Linux Ubuntu), which should not affect the actual image data.
I understand that this target will be challenging and the magnitude estimates will have huge error bars, but I still would like to get some estimate :)
I've been using vphot for a few months now and it is working great for plenty of other images taken with the exact same telescope/camera.
jf
Hi JF,
The error you are seeing is a secondary error: In faulted when it tried to display the error in a message box.
The image with the gain pushed like this has a sky background of about 20k. None the less, the Single Image Report for the stacked image is showing a reasonable result.
Note VPhot is not showing the target because it is not in VSX. Which will mean the data cannot be submitted to the AID until you send a request to the VSX team to add the target.
And Comps are not being displayed because for a fov of 1.2 deg only comps down to mag 15 are being shown. There are comps there, as you have found.
George
George,
So, out of curiosity, I gave it another try. After loading my sequence onto the stacked image, I was pleased to see that my comp and check were still there. With renewed hope, I clicked on the 'View Photometry Report' button and this time it worked!!! I got a magnitude estimate of 18.5 (if I remember correctly). But then, I got greedy... I decided to add more comp stars to the sequence. After adding these new comp stars, I'm back to the original error message :(
The target is in VSX (ASASSN-18dg). I was not aware of the limitation for magnitude of comp stars with large FOV. Is there any way to bypass this restriction? Should I crop my images to allow loading fainter comp stars?
Thanks,
jf
JF;
You should be able to select faint comps on your image manually and put them in your sequence. You just need to add/edit the filter magnitudes (edit sequence) for each comp in the saved sequence. Gather the magnitudes from the photometry page of the VSP. Make sense?
Ken
PS: I'd recommend using 3 as the min SNR in vphot settings to make sure you can identify all the available faint comps. Use the brightest of these faint comps first to make sure you can identify them.
JF:
The gain you mentioned is in decibel units. The gain you want to list in your software and vphot telescope settings is in units of electrons per adu unit (e/adu).
Ken
Thank you Ken. I've updated my telescope configuration(s) to provide the correct gain values.
I don't know if that's what made the difference, but this time, after deleting and re-uploading all my files, I managed to use my custom sequence for ASASSN-8dg and I have a magnitude estimate to report :)
Thank you all for your help!
jf