The Star Mass Project--Desired Data

(c) 2022 by Barton Paul Levenson

In case anyone wants to contribute to this project, here's what I'm looking for:

1. New stars.
2. Reasons to remove stars already on the list.

There are four things I need to add a star to the list:

• Its identifier. Make sure it's not already in the catalog. A good source to check multiple identifiers is the on-line SIMBAD catalog, which can be found here.
• Its spectral type (preferably with a luminosity class). Be careful of sources which list only an "overall" or "system" spectral type--this means the spectral type for each component star of the binary has not been disentangled, although separate figures may be given later in the article. If no spectral type is given, but the article makes clear that the star is on the main sequence, you can send me the effective temperature (T_eff) instead. I can tell the spectral type from that.
• Its mass in terms of the sun. Some sources give masses in terms of Jupiter for very small stars--please note which is being used.
• Error bars on the mass figure. I prefer probable error, which is what is usually used, but some sources give standard deviation or weirder variance figures--again, please note what is being used. If the authors don't say what the error figures are, they're almost certainly probable errors. If more than one figure is listed next to the mass--for example, a star may be listed as having a probable error of both superscript +0.006 and subscript -0.007 Solar masses, that means the error bars are different in different directions. Use the figure of greatest magnitude.

A main sequence star paired with a non-main sequence star in a binary is okay, as long as they're not interacting. Avoid any of the following types of system:

• Algol binaries. These were either interacting in the past or are interacting now. Watch out for any article where "mass transfer" is mentioned.
• Cataclysmic variables.
• Contact binaries.
• "Interacting" or "interactive" binaries.
• "Polars" or "Polar binaries."
• Semidetached eclipsing binaries.
• W UMa binaries.

Avoid any of these types of star:

• Pre main sequence stars. These usually come in pairs. PMS stars paired with MS stars are almost nonexistent.
• Giant stars of any kind--subgiants (luminosity class IV or IV-V), giants (II, III, II-III, III-IV), supergiants (Ia-0, Ia, Iab, Ib).
• Subdwarfs. This used to mean a kind of metal-poor main sequence--luminosity class VI--and stars of that type are perfectly acceptable. 30 μ Cassiopeiae is an example. But it has come to mean post-main sequence stars of a certain type, usually of spectral class B. Avoid these.
• Don't use figures listed as M sin³ i. These are minimum masses, listed for systems where they can't tell the inclination of the orbit. They are not masses.
• Don't use figures where they estimated the masses from a mass-spectrum relation, or mass-temperature. That's what we're trying to build here, so citing these would be arguing in a circle! I only want "dynamical" masses, usually from detached eclipsing binaries or visual/astrometric binaries.
• Any star listed as filling its "Roche lobe," even partially. These stars are in very close binaries, and they could be subject to mass transfer. I just don't want to take the chance.

I have succeeded in taking some stars off the list which were subgiants, pre-main sequence, or in semidetached eclipsing binaries. Detached eclipsing binaries are very nice and useful; the majority of stars in the catalog come from that type of binary. But beware if the word "Algol" is used in an article on a DEB. That blows it.

I'd especially like to discuss this project with any actual stellar astronomers. You can reach me at this link. To anyone who participates in this, thanks in advance! I will acknowledge anyone who does so on this web site.