How to create "fainter than" report in VPhot

Technology VPhot
1

Is it possible to use VPhot to directly create a “fainter than” report for a target? For example, I have some AAVSONet images where the target is so faint that it shows up as red (unidentified) in the image in VPhot. (I have loaded a saved sequence that contains that star as a target.) But it only shows up in the image and not in the list of stars in the sequence on the left side of the screen. I’d like to just select it as the target somehow and have VPhot create a photometry report that shows it as fainter than the limiting magnitude. Is that possible?

Brian (SBQ)

2

Brian:

  1. In Single Image Photometry page, see the < column. Try it out and see what it does.
  2. In tools/settings, choose/set a minimum SNR to import to about 3-5, to show all your faint targets.
  3. If the target is not detectable (SNR<3), you would need to manually edit your report. Reporting such non-detect targets is not a good practice.

Ken

1 Like
3

Ken,

Thanks for the information. If it’s not best practice to report a fainter than result in cases like this I won’t worry about it. (The star in question is V381 Lac, an RCB star that has now dropped below magnitude 20, so to say the least it’s a difficult target.)

On the Single Image Photometry page I do see the check box in the ‘<’ column for any target star, but in this case V381 Lac doesn’t show up as a target and I’m not sure if it’s possible to force it to. I’ve tried setting min SNR to 1 just to see if it would show up and it still doesn’t, so it is really just not showing up at all as anything but a red, unidentified object in the image.

Brian