American Association of Variable Star Observers (AAVSO)
Tue, 12/13/2016 - 00:13

AAVSO Alert Notice 564 announces an urgent campaign to obtain single images of 21 CVs over the nights of December 14-15 UT and December 15-16 UT and submit those images to this forum thread no later than December 16. Full instructions, timeline details, and the list of targets are given in the notice.

Many thanks for your assistance, and Good observing!

Elizabeth Waagen, AAVSO HQ

Vereniging Voor Sterrenkunde, Werkgroep Veranderlijke Sterren (Belgium) (VVS)
CVs I observe during several nights



I am observing AY Psc since long and also the past nights and coming nights (weather permitting). Last night is was at about mag 14.5 CV hence at its maximum.

I also started observations of LT Eri for CBA. Last night I got it at about mag 15-17 depending on the time of exposure. There seems to be an eclipse as the minimum brightness went below 17 but SNR was too small to be counted as good observation.

Data will be uploaded to the AAVSO database.




American Association of Variable Star Observers (AAVSO)
A few results (faint ones)

I was able to get very faint results on all but AR Cnc, HT Cas, PTFS1201n, PTFS1204h, and PTFS1508bh. In all but a couple the target star is barely detectable, and half have one offset star visible and the other half have 2 or 3 offset stars visible (all images have the full field of view). I'll increase exposure times tonight to see if I can get better data. All images are stacked to get this final exposure, and the exposure time for each target is in the FITS header. All images are taken with the R filter. Hopefully I'll get something more useful the second night around, I haven't tried targets this faint before so apologies for the initial quality.

The reduced images are available here:



21 PTF CVs campaign

Hi all,

Thank you so much for your interest in this campaign! 

Just a quick comment, all of the targets are eclipsing. If you happen to catch them in mid-eclipse, they can be very faint. Nevertheless, even non-detections are useful for me because I need to know if they are in outburst or not and non-detections point in the quiescence direction. 

I appreciate all your contributions. I am observing myself as well at the Isaac Newton Telescope at La Palma (for a different project), and weather is holding nice here. I hope you also have clear skies!

Good observing and thanks again.


American Association of Variable Star Observers (AAVSO)
2nd night

Got some more data last night, longer exposures got much better results. Weather was also slightly better as well. Images have been added to (R filter, exposure times in the FITS header) and I looked at them with VPhot to see the magnitude ranges I was getting compared to the given offset stars. Error ranges were higher than what I usually end up with since a lot of the stars had a low SNR, definitely challenging targets for my setup.

VPhot results:
PTFS1523ak - 17.385 +-0.035
PTFS1500w - 16.240 +-0.055
PTFS1500bs - 17.871 +-0.083
HT Cas? no offset stars
PTFS1501br - 17.877 +- -.516, not sure what happened here to get the high error
PTFS1201n - no image
PTFS1402x - 17.115 +- 0.081
PTFS1504k - 15.658 +- 0.019 using 1 offset star (brightest)
PTFS1604m - ? unable to read image in VPhot but it looked ok in MaximDL
PTFS1204h - not detected (offset stars were all detected)
PTFS1606dc - 16.169 +- 0.054 using 1 offset star (brightest)
PTFS1508bh - not detected (offset stars were all detected but the one at 18.24 had an SNR of 9 and 17.5 had an SNR of 17)
PTFS1509n - not detected (offset stars were all detected)
PTFS1109e - 16.161 +- 0.101, 16.104 +- 0.032 without the weakest offset star
AR Cnc - not detected
PTFS1609t - 18.396 +- 0.122
PTFS1509ao - 17.749 +- 0.106
PTFS1509as - not detected (2/3 offset stars detected)
PTFS1510aw - 18.222 +- 0.143
PTFS1310as - 17.163 +- 0.251, 17.082 +- 0.099 using 1 of the offset stars (brightest)

Hope this is helpful.


American Association of Variable Star Observers (AAVSO)
Folder update

Great! Really glad they worked out! I had to make a change to the folder's security to prevent any bots from eating my bandwidth so if you still need to access that directory the username is "aavso" and the password is "21_ptf_cv" minus the underscores. Let me know if there are any problems accessing it if needed.