Is a star, found on one or more of those publications (see below), listed in Vizier, would be considered as an already known variable star, or is it worth working on that case ?
At first sight, I can’t find any specified variation type or period in those papers/catalogues, but I prefere to ask, rather than loosing some precious time.
Thanks for any answer and advices,
Christophe
Northern Sky Variability Survey: Public Data Release.
2004AJ…127.2436W
Chromospheric Activity of M Stars Based on LAMOST Low- and Medium-resolution Spectral Surveys.
2021ApJS…253…19Z
Reconstructing Intrinsic Stellar Noise with Stellar Atmospheric Parameters and Chromospheric Activity.
2024ApJS…272…40Z
Stellar chromospheric activity database of solar-like stars based on the LAMOST Low-Resolution Spectroscopic Survey. II. The bolometric and photospheric calibration.
Unfortunately the answer is not as simple as you might like. Stars often get mentioned as part of a survey, but that in an of itself is not really enough. If the star isn’t mentioned by name in the paper, with a variability type or further information on it, then I wouldn’t consider it to be discovered. It really just depends on what the papers actually say, and to know that you will have to look through them yourself and see.
general remarks by Bert are correct, since it will depend on each paper’s focus.
In particular, the papers you mentioned have studied stars spectroscopically and they are not focused on light variability, which is what we consider for VSX inclusion.
In the case of the NSVS catalog, it is a photometric catalog, but what you find in VizieR are the all-sky results, not a variable star listing, thus the fact that you find an NSVS entry does not mean the object is a variable star.
All NSVS variables have been incorporated to VSX several years ago so you can forget about that one in particular.
So when you check for previous publications, see if there are amplitudes, periods, variability types, and if that is the case, then you can be sure the stars have already been discovered.
Main examples of publications like that -and not yet in VSX- are the ATLAS catalog or several papers based on TESS data.
This is always work in progress…
Thanks for those important precisions, Bert and Sebastian.
My questions seems probably of little interest, but as amateur, it is not always easy to determine what is important and what is not.
I have seen a lot of papers and catalogues based on TESS data, and I eliminated some variable candidates I had on this basis.
The main part of the variables I found are EA, with a few ROT of low amplitude.
The EA are mainly of medium to long period, but some are of small period (0.5 to 50 d, and possibly more, up to 400d). But they are faint, between 15 to 17 and more.
The coming weeks will see if they are really unkown, or not.
I think I will have a few more questions to come, if you don’t mind.
Hi Christophe,
finding EA stars is not easy, the short period ones are usually already discovered and the long period ones are difficult to solve.
Long period EAs are my favourite type of stars so I am really eager to see them submitted to VSX.
But what I have learned since, and from my first submission to the VSX (an aborted submission - indeed, it was an allready known LAMOST star - I was naive at this time), is that all this stuff is a very very very very long process.
Finding a variable star candidate is quite easy in fact - there may be a lot of them lurking around at first sight - ; but the main issue, after the initial discovery is to assemble all the avaiblable data, and construct the phaseplot after having detrended the data, and found the period. A lot of copy-paste-cut clicks with a spreadsheet.
So I’m currently coding a python app so as to be able to handle all this process more easily in a few minutes max, from the initial discovery to the phaseplot, with some automated queries to get the main data from ZTF/ASAS-SN/Vizier and so on, altogether with an automated process to confirm or not the discovery by searching in the VSX, Gaia GrappaVar database, and Vizier.
Of course, that’s a long process to code such an app, but the overall process to characterize a star and submitt it to the VSX is so paintfull, that I think it’s worth spendind a few months to deal with python to automate the process.
Well, about an EA (period around 393d), I found lately, I only have to deep eclipses. The next one should occur in next december. We have to observe it before submitting anything about this star. Moreover, I don’t know if I have 2 primary eclipses, or a primary and a secondary eclipse. It may be that this sytem is an eccentric one, because the two eclipses I have found are not totally symetric. Which could render the task a little bit more complicated. Anyway, we will see.
By the way, Sebastian : when submitting a star, is there any convention to choose between the all available aliases to give a name to the star ? I suppose the oldest classic catalogues should be prefered (HD, BD, ./…) if there exists, but what about a faint stars : should I stick preferably to a Gaia name, or a TIC name, or could I add first a name like XXXX J2000, XXXX being the name of our small network of observers ?
Have you seen this paper ?
Very interesting, useful and amazing process :
( TESSELLATE: Piecing Together the Variable Sky With TESS)
In fact, to streamline my variable star data processing workflow, I previously developed a Python script.
It can handle data from ZTF, TESS, ATLAS, ASAS-SN, and other sources, supporting data merging and generating CSV files compatible with Vstar (I haven’t integrated validation features for discoveries yet, as building a comprehensive database of known objects proved too complex).
This script remains under active development and occasionally encounters edge cases. Due to various considerations, I haven’t open-sourced it on platforms like GitHub.
However, if you’re interested, I could email you the script – it might offer some inspiration for your project.
Hello Jiashuo,
Well, I can see that we followed almost the same way to solve the issues about finding and characterizing new variable stars.
It may be a good thing to share some ideas and experiences in coding a usefull app in this particular domain. I will contact you in private mail.
Many thanks for this nice proposition.
Cheers,
Christophe
I recommend submitting the 393 d. eclipsing binary anyway.
With the star already in VSX, your discovery already credited and an AUID assigned, you can start a campaign in the forum, people will be able to observe it and we will have provisional ephemeris to make the task easier. If no eclipse is seen in December, we will know it is eccentric.
Be sure to use all available data in search of another eclipse (e.g. ZTF, CRTS, TESS, ASAS, ASAS-SN, DASCH).
About star names, you are right, old-time catalogs should be included in the list of names. For those that are fainter, you just add the names in the catalogues including the star, like 2MASS, USNO (A2.0 and B1.0), UCAC4, etc.
But I think you meant the primary name. If you are data-mining a specific survey or doing a systematic search using some catalog, it is recommended to adopt that catalog name. E.g. if you do a search of variables using TESS, adopting the TIC number would be fine.
If the stars are bright, their HD identifier would be a better choice because those catalogs are very popular.
If you are doing your own systematic search of variable stars (not isolated findings) you can use your own identifiers. Usually they are made of an acronym (your observer code, your initials, your observatory or project name) and then an ordinal number (e.g. BMAM-V930) or J2000.0 coordinates (e.g. STSP J173926.62-180205.2).
I took a look at the paper. Very interesting. More work for the future for us cataloguing the variable sky! and
and 