Talk:Eta Carinae

Variability
"One remarkable aspect of Eta Carinae is its changing brightness. When it was first catalogued in 1677 by Edmond Halley, it was of the 4th magnitude, but later it brightened, reaching its greatest brightness in April 1843"

I don't know how to word it, but could the 2nd sentence be changed without getting too detailed, to indicate its varying brightness so readers don't think it only brightened from 1677 to 1843. Also, is it too fine a point to say "greatest *recorded* brightness in April 1843"? — Preceding unsigned comment added by Jeandré du Toit (talk • contribs) 11:16, 19 January 2003

Apparent magnitude out of date?
There are two conflicting magnitudes listed in the article. It appears eta car has apparent magnitude around 5.1: AAVSO — Preceding unsigned comment added by 132.206.150.195 (talk • contribs) 08:48, 30 May 2007


 * Someone should mention that this explosion is mostly harmless because main burst will not hit Earth. Even by 7500 ly we would be toasted in direct hit. Source: [here].


 * "Note that the lobes appear to be tilted away from us by about 40 degrees or so. That’s a good thing. When stars like Eta Carinae explode, they tend to shoot of beams of energy and matter that, at its distance of 7500 light years, could kill every living thing on Earth. But since it’s pointed away from us, all we’ll get is a spectacular light show." — Preceding unsigned comment added by 80.51.70.116 (talk • contribs) 13:19, 21 June 2007
 * I believe astro-physicists now give a distance of 650 light years or less to be lethal, not 7,500. — Preceding unsigned comment added by 50.111.16.144 (talk) 07:00, 12 March 2022 (UTC)

True size of Eta Carinae
Does anyone know the true size of the star? Is it likely to be closer to 60 or 881 solar radii? Is there a more recent source with a diameter? Nussun05 (talk) 06:54, 1 July 2020 (UTC)
 * Almost a meaningless question. See previous discussion about exactly this.  The wind from the star is so dense that it is effectively impossible to define where the surface is.  The traditional 2/3 Rosseland radius is definitely nowhere near anything that could be called a photosphere, it is just somewhere that the wind starts to thin out.  Wolf-Rayet researchers tend to use an opacity of 20 as an arbitrary location that can be called a surface.  The location of a surface where material is largely gravitationally bound is likely to be even deeper than that for η Car.  There are two representative values in the starbox, for a "core" and the "opaque edge of the wind", discussed in the text and explained in the reference.  Picking any other value is more a matter of semantics than a meaningful radius.  Given that we can't even define a sensible effective temperature for the star (because we can't actually see it, yet), it is all guesswork anyway.  Lithopsian (talk) 11:56, 1 July 2020 (UTC)

Page lock
XKCD is at it again. This page should probably be locked to prevent vandalism, at least temporarily. We all know why. 2601:601:1801:3FF0:2DAD:D5F1:F9EF:F332 (talk) 00:52, 17 September 2020 (UTC)
 * I'll bear it in mind. A couple of insertions of an unnecessary spammy hatnote don't yet call for page protection.  Lithopsian (talk) 14:26, 17 September 2020 (UTC)

Distance
The details of the first graphic (Homunculus Nebula) give the distance as "more than 8,000 light years"; however, Astrometry in the infobox gives the distance as "7,500 ly", as does the detail for the fourth-last graphic. The Distance paragraph has 7,600 ± 330, i.e. between 7,270 and 7,930 ly; so the first graphic would appear to be anomalous. Prisoner of Zenda (talk) 12:31, 2 May 2023 (UTC)
 * Are you just reading the 1996 NASA press release? Unfortunately, it is above my pay grade to proofread and fix everything NASA has ever published.  You could edit the image description in Wikimedia Commons, but that opens up a whole other can of worms.  Keeping it matching the original NASA text avoids issues of verification and sourcing of whatever else you might write.  Lithopsian (talk) 13:52, 2 May 2023 (UTC)