Does anyone know the current policies, status and progress of the IAU on naming variable stars ‘discovered’ by large sky surveys?
When I go to the IAU page Commission C Working Group on Star Names, I can’t see anywhere this issue is addressed.
The question was prompted by my recent serendipitous ‘re-discovery’ of an EA eclipsing binary near BF Pav, with data in both TESS and ASAS-SN. Searching in VSX using the position yields the ASAS-SN data.
Greetings,
I wouldn’t get my hopes up on any standardization of names now that there are so many!
Most of the surveys have gone to giving the coordinates as part of the name. Others have their own system naming schemes but always report the positions accurately. VSX has a, often long, list of alternate names. If publishing the common recomendation is to give several names if available and a good position.
The IAU ain’t what she used to be is all I can type.
Jim (DEY)
Indeed, with the commencement of numerous large-scale sky surveys, a vast number of new variable stars have been discovered.
For exoplanets, they might use designations like TOI, such as TOI 6883A. For variables previously listed in the GCVS, they carry established names.
For the current large-scale surveys, coordinates are typically used as names—e.g., ZTF J173841.97+703715.3, GDS_J1842008-021733, CSS_J102714.3+205943, WISEA J205237.60+742907.8. Alternatively, internal alphanumeric codes are used, like ZTF18abtvqrl.
For Gaia DR3, we use Gaia IDs, such as Gaia DR3 2148402530483653120.
For the numerous variables discovered by TESS, TIC numbers are generally adopted as prefixes, like TIC 239133160—though this isn’t absolute.
For UG-type variables reported to the CBAT, it’s customary to call them TCP (e.g., TCP J19181542+3158142). For the TNS, corresponding identifiers are used (though TNS currently seems to discourage submitting variable star discovery reports).
For new variables discovered by amateurs, practices often mirror those of projects like ZTF—e.g., my discovery STSP J020810.62+794842.2. Sometimes designations with numbers are used, like Barlad V48 or CzeV926. Occasionally, bright variables may adopt IDs from historical surveys (e.g., HD, TYC, BD, URAT), such as HD 54896, TYC 7302-850-1, SAO 59882.
However, since each variable star likely exists in multiple catalogs, they typically carry several names. For instance, HD 54896 lists 12 “Other names.”
As Jim noted earlier, given the sheer number of variables (and considering future projects like Gaia DR4, WFST, and LSST will discover many more), standardization of naming is clearly unrealistic. For such a vast quantity, specific names seem less critical.
P.S. Relevant information is noted in the VSX FAQ and Guidelines.
I may not have been specific enough. I know the IAU still names novae in the traditional format Vnnnn (Constellation) (e.g., the recent Lupus and Vela novae are now V462 Lup and V572 Vel). But what about other types of variables, abundant in the large surveys? Is the former nomenclature Vnnnn (Constellation) as a matter of policy no longer applied to new discoveries? Because there are too many of them?
As for various catalogues, each of course has its own format for object identification, but the same format may be used whether a particular star is variable or constant, i.e., the identifier itself does not tell you if the object is variable.
Hi Roy,
What you are referring to is the GCVS naming system, so it is up to them to assign those designations. Back in the day (in the pre-survey era), when the number of variable stars discovered was easier to manage, checking the literature was enough to find the most recent discoveries and assign GCVS names to them. Later on, surveys came into the picture and -since the GCVS approach is focused on quality and not quantity, checking one by one the information on the increasing number of published discoveries became impossible to manage.
Hipparcos was the last individual survey that I remember having its variable stars checked and GCVS and NSV designations assigned to them. 25 years ago things got out of control.
Right now the GCVS is naming variable stars of interest like novae or other unusual objects, usually through CBETs, and they are publishing Name Lists of variable stars in globular clusters (their last Name List is still not imported to VSX, we are working on it).
I wouldn’t expect GCVS name assignments for the millions of stars discovered by surveys.
There is a good thing about this: if the object has a GCVS designation, it is very likely that it has gone through a thorough vetting process (especially the ones published in recent decades). Most of the survey objects added to VSX (e.g. Gaia DR3), have been added but not checked. The individual approach is no longer feasible in today’s scenario.
And that is why it is important that all these millions of stars are confirmed, checked, reclassified and studied by individual observers, with their own observations or data-mining databases like TESS, ZTF, ASAS-SN, etc.
Cheers,
Sebastian
Sebastian makes some good points here. One could suspect that the usefulness of the GCVS designations has gone away. When Argelander set up the original scheme, he clearly figured there would be need only for letters P through Z in each constellation. Perhaps the Moscow folks will assign their names only to variables brighter than, say, mag 12. For instance, one could wonder whether it is helpful to know that a faint semiregular buried in the Sagittarius starcloud is V132654 Sgr versus something like the 2MASS name. I think not, since the 2MASS designation (as an example) allows direct connection to source data (JHK photometry) and has good astrometry.
\Brian
Maybe, there is a sense to mark automatically classified types with colon?