Mon, 10/15/2018 - 15:58
I have written a plugin for VStar that allows you to read light curve data for any of the Gaia DR2 stars that were identified by Gaia processing as variable and therefore have photometry available. Data are accessed directly from the Gaia web service. The passbands can either be the Gaia red (RP), green (G) and blue (BP) or they can be transformed to V, Rc, Ic.
The plugin is now available with all the others on the VStar plugin page where you will find more complete documentation on it. You can also install it via the VStar plugin manager where it becomes available after a program restart.
Feel free to provide feedback and ask questions here.
The attached spreadsheet contains 5,642 objects from the VSX that have observations in the AID and also match an object Gaia found to be variable in data release 2. The Gaia source_id is provided so that you can merge the AID and Gaia light curves in VStar.
thanks for all your work developing the plugin and also for the spreadsheet, they will provide hours of cloudy-night entertainment! I hadn't realised GAIA could do useful photometry of stars as bright as mag 2.
Any hints on how I would go about generating a list of GAIA variables with VSX names but with no observations in AID? Obviously this would potentially be a huge list so I'd look at limiting it to variables with maximum magnitude of 10 and negative declinations. Even that list could be quite large.
To obtain that list, I used the Topcat application on my desktop. I took all the Gaia potential variables and all the VSX objects and performed a crossmatch on coordinates. Both of the inputs had about 0.5 million entires. The matches were in the range of 110-125,000, depending on the match limit. I then put the results in a spreadsheet and realized after the fact that the number of AID observations was going to be interesting. I added that into the spreadsheet. The full spreadsheet (with and without AID observations) does fit within this forum's limits and is attached. I suppose if ones desktop can handle gobs of FITS files it can handle a big spreadsheet. Do consider the possibility that my crossmatch may be imperfect.
Regarding the saturation limits of Gaia, it does seemto me to go brighter than many surveys. Like all surveys it takes time to understand the limitations. For Gaia, those limitations relax with the 2nd data release and likely will with the next release as well. For a quick start, the executive summary is probably key. To your point:
"The survey represented by Gaia DR2 is essentially complete between G=12 and G=17 mag. At the bright end, the completeness has improved compared to Gaia DR1. At G<7 mag, however, there are still many sources missing from the catalogue, primarily due to the difficulties of treating saturated CCD images. Fainter than G=17 mag, the completeness is affected by a combination of data processing limitations in crowded fields and the filtering applied before publication ..."
That's quite a large Excel spreadsheet. I'll extract a subset to work with. Cheers,
Would you please explain, how to get Gaia photometry for star 935768683971760128, if plugin shows server response code 503?
The Gaia folks made a change to the URL.
This has been fixed but is not yet released.