Talk:List of largest stars

I've seen a few people say the star CI Cephei (which isn't on the list) is the largest known star. Does anyone have any information on this? LobedHomunculus (talk) 21:27, 3 March 2025 (UTC)

:Unlikely. It isn't even a supergiant. Some semi-automated survey may have published a very large radius, although I can't find it. Otherwise, someone may have combined a very low temperature (this is a cool star) with a high luminosity and come up with an answer. The wrong answer. Lithopsian (talk) 21:31, 3 March 2025 (UTC)

:A Mira variable according to SIMBAD. Mira variables can't have sizes over 1,500 times larger than the Sun, they are usually between 100 and 1000 solar radii, so i doubt this size is real. 21 Andromedae (talk) 21:40, 3 March 2025 (UTC)

:ok LobedHomunculus (talk) 16:27, 4 March 2025 (UTC)

:Never mind, they were talking about CU Cephei, not CI Cephei. LobedHomunculus (talk) 17:51, 30 April 2025 (UTC)

According to NGC 2403 V14's Vizier, Gaia DR3 1089775697125470080 (which has the same exact coordinates of NGC 2403 V14) is listed being only about 2,400 parsecs away, meaning it would certainly be in the Milky Way not NGC 2403. It even has a similar magnitude of NGC 2403 V14.

Is this right or wrong?

Source: https://vizier.cds.unistra.fr/viz-bin/VizieR-S?Gaia%20DR3%201089775697125470080 https://simbad.cds.unistra.fr/simbad/sim-id?Ident=EV*+N2403+V0014 Orangefanta120 (talk) 03:04, 30 March 2025 (UTC)

:This distance is based on low-resolution spectra and hence unreliable. A similar example is HV 888, which was reported as a foreground star in the Gaia database, but it was a false alarm because the distance implied would make it a halo star, a region where red supergiants do not form. Also, the parallax in the Gaia database is negative, already suggesting this star is distant... 21 Andromedae (talk) 11:03, 30 March 2025 (UTC)

::Thanks for the clarification! Orangefanta120 (talk) 12:50, 30 March 2025 (UTC)

As mentioned in the stars notes, the radii listed for them may be overestimated due to TiO lines being used for temperatures leading to possibly underestimated temperatures. The paper also gives a scaling relation to get 'better' temperatures, which can be used to recalculate the radii of the stars. Should I add these new radii or leave it as is due to WP:SYNTHESIS ? Infa 65 (talk) 16:00, 4 April 2025 (UTC)

:It's better to use the radii already in the reference (i.e. not recalculated by us), so no. 21 Andromedae (talk) 17:06, 4 April 2025 (UTC)

:I would be in favour if the scaling relation wasn't extremely uncertain, which it unfortunately is. I would rather leave them as they are or simply remove them as a whole. SpaceImplorerExplorerImplorer 10:08, 5 April 2025 (UTC)

:See WP:SYNTHESIS. Using any algorithm other than the most universal and exact (eg. diameter = 2x radius) from one source to transform a radius from another source just isn't allowed. For a less arbitrary reason why we shouldn't do this, how are we to be sure which published sizes should be transformed? Are there cases where a radius is derived from a combination of methods, and should only be partially transformed? The whole thing just isn't something we are competent to "fix". Lithopsian (talk) 16:56, 6 April 2025 (UTC)

This article https://iopscience.iop.org/article/10.3847/2515-5172/aba3cf seems to show a lot of red supergiants, even a {{solar radius|1,708}} red supergiant. I am just wondering if this article is accurate or not, if it is, I will add all these stars. Orangefanta120 (talk) 21:48, 5 April 2025 (UTC)

:Most of the RSGs are unconfirmed members of IC 10 and are only classified by magnitude and colour index, so no. SpaceImplorerExplorerImplorer 10:16, 6 April 2025 (UTC)

::Alright. Orangefanta120 (talk) 15:46, 6 April 2025 (UTC)