Talk:Delta Scuti variable

The article incorrectly claims, that He ionization increasing, leads to lower opacity 24.143.65.75 (talk) 02:43, 6 August 2011 (UTC)[reply]

Vega and Altair

Hi Bob (RJHall). I don't recall seeing any suggestion that Vega is a delta Scuti. Do you have a reference? But Altair definitely is, we showed this using the WIRE satellite (Retter et al.). Timb66 23:37, 12 November 2007 (UTC)[reply]

Hi Timb66. The Vega article includes the following reference regarding its variability:

Fernie, J. D. (1981). "On the variability of VEGA". Astronomical Society of the Pacific. 93 (2): 333–337. doi:10.1086/130834. Retrieved 2007-10-30.

Of course, it is only suspected.—RJH (talk) 19:20, 27 February 2010 (UTC)[reply]

Magnitudes in V

Huh? What's V? Please add a parenthetical remark. —Preceding unsigned comment added by 80.246.32.33 (talk) 11:14, 28 May 2010 (UTC)[reply]

I have linked "V" to the colour_index article which explains the nomenclature. George Dishman (talk) 11:35, 29 June 2011 (UTC)[reply]

Apparent contradiction in the text

The article first states ".. becomes more ionised, which is more opaque." which ties up with ".. the star has highly ionised opaque helium in its atmosphere ..". However, it goes on to say "The energy .. causes the helium to heat up, expand, ionise, become more transparent .." (my emphasis). It can't ionise any more if it is already fully ionised, and if only partially ionised, further ionisation would make it more opaque according to the previous sentence. My understanding is that once fully ionised (He++), the expansion on heating reduces the opacity but can this wording be clarified by someone more familiar with the details of the mechanism. George Dishman (talk) 11:16, 29 June 2011 (UTC)[reply]

This self-contradiction is still in the article, 12 years later. I've tagged it and added a maintenance template. Modest Genius ^talk 11:44, 6 November 2023 (UTC)[reply]

I'm by no means an expert, but the reading I've done suggests that the helium is ionized when the star is at its smallest and hottest, but when at its maximal radius, the helium is de-ionized, which makes the helium transparent. I can make the necessary edits if the explanation is satisfactory? Patchworkpieces (talk) 01:43, 7 February 2024 (UTC)[reply]

https://arxiv.org/ftp/arxiv/papers/2110/2110.09806.pdf <- This is a decent source for that, I think. Patchworkpieces (talk) 23:33, 7 February 2024 (UTC)[reply]

It seems likely to me that the high heat of the opaque helium would cause it to rise rapidly. Then when it reaches the top and expands, it would cool and become transparent again. This could lead to a convection cycle which is more powerful than normal hydrogen convection. Thereaverofdarkness (talk) 05:05, 11 April 2024 (UTC)[reply]