Talk:Rigel

Rigel and Rigel A

Lithopsian and Casliber, Hello, I would say that terms need to be defined before they are used. So, while "Rigel" might be the same, in some sense, with "Rigel A", at least when talking about the primary, we need to let the reader know (who is not likely to be an astronomer) that "Rigel A" is the primary, at least when we start using the term "Rigel A". That "Rigel" has been previously mentioned does not help the reader when, all of sudden, we start referring to "Rigel A" without defining it. Let us please fix things in the third paragraph of the lede. Thank you. Attic Salt (talk) 13:50, 5 June 2020 (UTC)

We screwed up - the IAU defined "Rigel" as the main component/primary. The whole is just "the (Rigel) system". and "Rigel" is the name of the main component, sometimes called Rigel A in that context, though it remains to be seen what happens as the IAU's definitions of names take hold. Cas Liber (talk · contribs) 14:01, 5 June 2020 (UTC)

Well, we all do sometimes. The last paragraph of the lede, where "Rigel A" is mentioned, needs repair. I am not happy with the convoluted nature of the first sentence of this paragraph either. Attic Salt (talk) 14:06, 5 June 2020 (UTC)

I trimmed it as it is obvious what it is 1/400th times as bright as. Cas Liber (talk · contribs) 14:08, 5 June 2020 (UTC)

That remains a problematic first sentence. I can't seem to figure out how to fix it, but the reference to 1/400th as bright leaves it confusing (to the non-astronomer reader) as to what comparison is being made. 1/400th as bright as Rigel, we know that, but the sentence is not clear. Attic Salt (talk) 14:13, 5 June 2020 (UTC)

My original wording was "400 times fainter" which is more obvious but a reviewer didn't like it. I thought it was obvious that it was referring to comparison with Rigel as what else would it be? The Sun? Cas Liber (talk · contribs) 14:16, 5 June 2020 (UTC)

"A faint companion of Rigel, referred to as Rigel B or Rigel BC, is 9.5 arc seconds away. It has an apparent magnitude of 6.7, making it 400 times dimmer." Or "400 times less bright." (Legit usage, albeit older.) Is that better? Fowler&fowler«Talk» 17:39, 5 June 2020 (UTC) Updated. Fowler&fowler«Talk» 18:00, 5 June 2020 (UTC)

FYI, this wasn't a concern of mine. My concern was about use of "away from" and "bright as" where, the association, though obvious to us, wasn't being expressed clearly (the association was with Rigel primary). I restructured the first part of the paragraph to attend to my concerns. I'm okay with either "fainter" or "brighter" since we have the association clear. My horse is now dead, Attic Salt (talk) 18:37, 5 June 2020 (UTC)

Are we all good? Just to throw a cat among the pigeons, do you think we need all the detail about component designations in the lead? As we've seen, it is difficult to express it all both clearly and concisely. It occurs to me that we could describe that there is a companion, itself triple, etc., in a lot less words and it would be easier to understand. Lithopsian (talk) 20:38, 5 June 2020 (UTC)

I'm always interested in brevity. Noting that much of our concentration has been applied to the lede, if we shorten the lede text, perhaps phrases that are removed can be used to improve text in the body. Attic Salt (talk) 20:43, 5 June 2020 (UTC)

Certainly, anything that is in the lead now should be in the body in at least as much detail. After that, possibly the lead can be simplified. Lithopsian (talk) 10:38, 6 June 2020 (UTC)

I think all the designation information is explained in the body of the article already. I edited the lead and removed all the multiple star designations. That paragraph is now slightly shorter, definitely starts out simpler, but becomes a little convoluted towards the end addressing the various orbits. See if you think it is an improvement. Lithopsian (talk) 13:52, 7 June 2020 (UTC)

Rigel /ˈraɪdʒəl/, designated β Orionis ... That makes me itch. My understanding is that the IAU decision is that Rigel refers to the A component, but β Orionis refer to the whole system - am I correct? If so, perhaps Rigel /ˈraɪdʒəl/ designates the brightest and only visible component of the β Orionis system...? That way the second sentence isn't necessary? Tarl N. (discuss) 00:23, 9 June 2020 (UTC)

I'm not sure the IAU has pronounced on Bayer designations, but certainly they tend to be used to refer to all the components of close multiple stars. For example, I don't think anyone would disagree with the designation β Orionis B, likewise β Orionis A. However, plain β Orionis is frequently used for the primary component alone, including by Simbad. I think we would be creating a precedent by insisting that it applies formally or exclusively to a system of however-many stars. The fact that you need to say "β Orionis system" suggests that it is not clear that β Orionis is the whole system. Your wording has an additional problem: "only visible" to who? I've seen Rigel B. Lithopsian (talk) 15:01, 9 June 2020 (UTC)

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)

Should we add an image showing Rigel components?

Found this image in commons: https://commons.wikimedia.org/wiki/File:Rigel.png This article mentions Rigel components lots of times but they are never shown visually. I think we should add this image. It was removed on the basis that it misleads making the user think the stars are actually that close to each other. That claim is valid but if the image were to scale it would be all points and features of each star as size and color would not be appreciated. I don't know. Milkayaculturekeep (talk) 02:20, 8 January 2021 (UTC)

No, I don't think it adds anything of accuracy. Attic Salt (talk) 02:22, 8 January 2021 (UTC)

See WP:ASTROART for the consensus policy on artistic representations in articles about astronomical objects. The key takeaway is that they must be from a reputable scientific source (although even some of those are wildly speculative and even outright misleading) and must be clearly identified as artistic impressions. This source doesn't seem to fit that criterion. See also the discussions on the talk page, there can be exceptions, for example for images clearly based on known scientific data without embellishment; much of the discussion is about how to represent exoplanets, but you get the idea. I don't think this one makes the cut. Lithopsian (talk) 18:04, 8 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)

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)