Affiliation
Magyar Csillagaszati Egyesulet, Valtozocsillag Szakcsoport (Hungary) (MCSE)
Tue, 10/11/2022 - 03:53
Within the framework of the Vend-RNe programme I want to check the latest brightness of several recurrent novae or RNe candidates in ZTF, TESS, GAIA and TESS databases. I have several questions.
1) Please could anyone help me how to find the LASAIR objectIDs in order to get recent ZTF observations? (Via VSX I can see only 3-4 month old ZTF observations.
2) Is there any way to get recent observations (from the recent 24 hours) GAIA and TESS missions?
Thanx in advance for the help!
Robert
Meanwhile I found the answer for the first question: "Lasair cone sear".
Thus KT Eri can be found here:
https://lasair-ztf.lsst.ac.uk/object/ZTF18abvtcuv/
https://lasair-ztf.lsst.ac.uk/object/ZTF20aarbvog/
Now I only need to learn how to get recent GAIA and TESS data.
Robert
Hi Robert.
No, do not use Lasair to get ZTF data.
Those brokers do not include all the observations or may have a different reduction (difference magnitude instead of apparent magnitude) than the one used in the ZTF data releases available through the NASA/IPAC site.
VSX has not offered the latest releases. All the data (now DR 13) can be obtained from
https://irsa.ipac.caltech.edu/cgi-bin/Gator/nph-scan?mission=irsa&submit=Select&projshort=ZTF
Enter the object's coordinates, use a 2" radius, run the query, then select all objects in the results list and click on "To Time series tool".
Then click on the OID links to see their light curves (some links are in r and others in g, and ther emay be i band observations too). You have options to configure the data columns you want to download (e.g. HJD, mag., mag. error, flag and filter) and then you can save the data as a csv file.
TESS (and Kepler) data are available though the MAST site, also after a positional search.
Gaia observations are available only for the almost 12 million stars classified as variable in the Gaia DR3 catalogues.
They can be downloaded directly from the VizieR results page after a positional search (using the VSX external links for that is easier).
In the Gaia DR3 part 1 results, there is a table called epphot listing all the observations.
Since your targets are known variables, it is very likely that they will have Gaia DR3 data.
And no, you don't get observations up to the last night like with ASAS-SN.
You can get recent ZTF data through ALeRCE (much better than Lasair) but only for objects that were included as ZTF alerts and with the limitation of using a different reduction. Waiting for the next DR is better (they seem to be releasing new versions very often).
Gaia DR3 also is a published catalogue, it is not being updated. If the stars are Gaia Alerts objects, you can get up to date light curves from the Gaia Alert entries. BUT -once again- you have to be careful because the zero points between the Gaia DR3 published results and the Gaia Alerts results may be different.
TESS releases new datasets from time to time.
Cheers,
Sebastian