Talk:Przybylski's Star

Hi, I wanted to help with something in the astronomy section. I found this one on the pages needing attention. Being new to this, what can I do to help, and shouldn't this be in the astronomy category, and not just physics? Thanks, Megalodon99 Talk 22:00, 14 April 2008 (UTC)

Transuraniums

Tc and Other Unstable Elements in Przybylski's Star by a W P Bidelman, claims presence of transuraniums up to Einsteinium detected in the spectrum of our oddball star. Rursus dixit. (^mbork³!) 13:02, 15 February 2012 (UTC)

Yes: Ac, Pa, Np, Pu, Am, Cm, Bk, Cf, and Es are all present. See for example [1]. Double sharp (talk) 02:52, 7 July 2014 (UTC)

Nuclear waste/weapons disposal?

Hi, just a possibility but could this system be a dumping area for alien WMDs?

Stranger things have happened, if you think about it a star is the ideal place. No risk of bad things happening, if it does go wrong then eventually any material will end up in the star though it may take a few centuries.

I would say that this is worth investigating. Look for a nearby (<25LY) system with unusual radio signals. — Preceding unsigned comment added by 88.81.156.165 (talk) 03:35, 5 September 2020 (UTC)

Update: as of yet this isn't an active SETI candidate but advances in optics may allow a possible neutron star nearby to be resolved. — Preceding unsigned comment added by 78.111.195.1 (talk) 15:46, 31 August 2023 (UTC)

Mass and age

For a long time the article has used the Tetzlaff catalog for the star's mass (4.0 Ms) and age (56 Myr) values. Some catalogs or scientific papers offer substantial different values, however. I added one (Mkrtichian 2008) but there are more: for example, the Catalog of Earth-Like Exoplanet Survey Targets (Chandler+, 2016) gives a mass of 1.3 Ms, and the asPIC1.1 catalogue (Montalto+, 2021) gives a mass of 1.416 Ms.

Any idea why the value reported by Tetzlaff is so different from the others? And should it still appear in the article if it's an outlier? It might come from spectral misclassification, since 4.0 Ms would be unusually large for an F-type star (and ~6.9 Ls for luminosity, if radius/surface temperature is even approximately correct, would be unusually dim for a star of four solar masses - it's rather similar to Procyon A). Daydreamers (talk) 13:06, 8 May 2022 (UTC)

Bulk catalogues like this tend to blindly calculate properties based on certain inputs with little or not sanity-checking. Different inputs can produce wildly different values, or the algorithms used may simply not be appropriate for a non-typical stars. Chandler, for example, tends to just repeat values from other catalogues, so look at the underlying source for an indication of how reliable it might be. A paper dedicated to the star would generally have more reliable properties, provided it was reasonably recent and not just repeating extremely old data, but be careful that underlying assumptions such as the distance haven't radically changed since the publication. Anders et al (2019 and 2022) give a mass of about 1.5 M_☉, as does Kervella based on Gaia DR2 or Gaia EDR3 parallaxes, and the TESS Input Catalog is even lower around 1.2 M_☉. I would suggest that is the right sort of mass to include in the article, just pick a suitable source. Lithopsian (talk) 16:52, 8 May 2022 (UTC)

Reasonable. I edited accordingly. I used the Anders et al. 2021 figure since it's recent and also very close to the value from Mkrtichian et al.'s dedicated paper, even if it seems it might be a bit on the higher end compared to some other recent (ie, not going off the B5 spectral classification) catalogs. Daydreamers (talk) 11:05, 24 May 2022 (UTC)

Eisteinium or not

There is a at least one possible source expressing caution about the identification of Es, and the reference already in the article discusses the caveats on the identification. Lithopsian (talk) 11:06, 29 May 2022 (UTC)

References