Skip to main content

Reporting GCVS and VSX variables in VPHOT

Sebastian Otero's picture
Sebastian Otero
Offline
Joined: 2010-09-19

We have found a problem with the way VPHOT handles the GCVS variables so we recommend the observers to stop using the GCVS for now to generate reports.
It looks like, due to different star name formats, the same star might be reported twice.
E.g. V0362 Her could be reported as such (VSX) but also as V362 Her (GCVS) and we would end up having a duplicate observation in the database. Actually we do have a lot of them :(

Making VSX and GCVS mutually exclusive would be a way out of this problem. If you want all variables, choose VSX. If you want GCVS-named variables, choose GCVS.
HOWEVER, the GCVS option is also giving several unwanted additional results (such as ROTSE stars with no AUID) and WebObs takes those names as valid thus generating new duplicates in the AID (Those names are alias names of other variables so the AUIDs of those other variables are assigned to them).

We need to investigate why these ROTSE stars (and maybe others) are being displayed in VPHOT as if they were GCVS stars when they are not, but until now, please, use the VSX option and not GCVS to display the variable stars in your image.

Cheers,
Sebastian

PS: Using VSX will also give you some duplicate results (specially in the case of ASAS and NSVS stars) but that is another problem that we are taking care of.

---------------
Sebastian Otero
VSX Team
American Association of Variable Star Observers

Re: Reporting GCVS and VSX variables in VPHOT
hgeagle's picture
hgeagle
Online
Joined: 2010-09-19

Hello Sebastian,

I just saw your message, but only by chance...

I think I am guilty, too, but like all others, I was unaware of those problems. I remember that I reported a ROTSE star some weeks ago that appeared unexpectedly as another reportable variable on the VPhot image. Of course I was very naively happy to get another report out of that...

Depending on how often the false reporting is happening wouldn't you think it would be worthwhile to make a more prominent announcement on the AAVSO website? I only saw your message by chance, but it appears to me to be quite important!

Just a thought...

Cheers,

Helmar

GCVS option being disabled
Sebastian Otero's picture
Sebastian Otero
Offline
Joined: 2010-09-19

Hello, Helmar,

VPhot was performing a SIMBAD query for any variable object instead of displaying only GCVS data so every wrong cross-identification (or lack of cross-identification) in SIMBAD was impacting VPhot.
Right now the VSX and GCVS options have become mutually exclusive (thanks, Geir). We will disable the GCVS option (actually a SIMBAD option) altogether to avoid problems (at least for now) as soon as possible.

Cheers,
Sebastian

--
Sebastian Otero
VSX Team
American Association of Variable Star Observers

GCVS option removed
kge's picture
kge
Offline
Joined: 2010-07-19

The GCVS option has now been removed.

Geir

The VSX/VPHOT/AID interaction
wel's picture
wel
Offline
Joined: 2010-07-26

The VSX/VPHOT/AID interaction is one where the whole is so much grreater than the sum of its parts! Well done Sebastian et al and Geir!!!!

Cheers,

Doug

Duplicate observations
BSJ's picture
BSJ
Offline
Joined: 2010-03-12

Thank you Geir for removing the "GCVS" option. I hope it doesn't inconvenience anyone not to have it, but I think it might have been causing more problems that it was solving. We now need to find a safe way to delete the duplicate observations in the database that were created as a result.

As Sebastian mentioned, there are still other ways in which duplicate observations can be introduced into the AAVSO report you create using VPHOT. Please inspect your list of target stars carefully and make sure that you are not reporting the same star twice under different names - particularly if one of them is an ASAS or NSVS star. Meanwhile, we will continue our efforts to remove these "imposters" from VSX.

AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484