Talk:Rigel

Absolute magnitude

Rigel is actually a multi star system. But the energy output of its components other than the main star are negligable. Its average apperent magnitude is m=0.13 and the distance is d=860 ly. With these figures its absolute magnitude should be M= -6.97 . But the article gives the figure as M= -7.84. Have I missed something? Nedim Ardoğa (talk) 14:42, 6 January 2021 (UTC)

Yes, you missed something. First, the references given for the apparent magnitude, the distance, and the absolute magnitude are not the same, so they are not necessarily consistent. In fact the reference for the absolute magnitude (which I just changed to the original paper that derived the value instead of one that was just quoting it) assumed a distance of 360 pc. There is also extinction, which many people forget about. In this case it isn't obvious how many magnitudes of extinction have been included in the calculation because the paper goes directly from the distance modulus and colour excess to the absolute magnitude. However, the difference between the distance modulus and the absolute magnitude makes it fairly clear that there are about 0.16 magnitudes of extinction in there. That is consistent with the E(B-V) of 0.05. Lithopsian (talk) 17:27, 6 January 2021 (UTC)

Distance

The first paragraph gives a distance of 860 light-years (260 pc) from Earth. Yet the sidebar lists Distance 1,010 ± 20 ly (309 ± 5 pc). KevinTernes (talk) 14:15, 15 September 2021 (UTC)

Thanks for pointing that out. I took a look and it seems that the infobox value was obtained using another method, but the value of 860 ly (863, to be exact) is the more widely accepted value. I have updated the infobox and added a reference. -Pax Verbum 18:54, 15 September 2021 (UTC)

The distance isn't consistent now to the measured parallax - which i think is a pretty accurate method for this distance. The simbad database also states that the Parallax is actually 3.78 (compare: https://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Rigel). Should the parallax be changed to reflect this value? Or is the gaia data which was used for the 3.2 value more accurate? 194.113.40.61 (talk) 07:18, 13 February 2023 (UTC)

The parallax in the starbox is for Rigel B. It should probably have a note to that effect since it isn't obvious from the reference. Yes, it is fairly accurate, but it is also somewhat indirect and potentially doesn't reflect the actual distance of Rigel. The parallax shown at Simbad for Rigel A is the old Hipparcos parallax because Gaia can't yet provide a useful parallax for such bright stars. The Hipparcos value is still widely-used as the "reference" distance for Rigel. Lithopsian (talk) 14:51, 13 February 2023 (UTC)

Pronunciation

I would rhyme this with Nigel, but is that correct? Would it be a hard G? — Preceding unsigned comment added by 2A01:4C8:1428:C467:F0B7:ED5:AF2E:FE81 (talk) 07:12, 2 January 2022 (UTC)

I rhyme it with Nigel, the 'g' as in jam. Some pronunciation guides give a hard 'g', but I haven't heard this actually being used. Lithopsian (talk) 17:38, 2 January 2022 (UTC)

And that corresponds to the tri-literal root RJL of the Arabic name (ar-Rijl al-Jauza, the foot of the giant). -- Elphion (talk) 18:27, 2 January 2022 (UTC)

Evolutionary stage

The sidebar says that Rigel is on the main sequence but the text says that it has evolved away from the main sequence. Presumably the text is correct 155.137.25.15 (talk) 11:20, 21 March 2022 (UTC)

The sidebar says that the faint companion, or at least one component of it if it is a binary, is on the main sequence. It describes the primary star (component A) as being a blue supergiant. Lithopsian (talk) 20:36, 21 March 2022 (UTC)