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Deneb Is a neat star. Most of the 30 brightest stars in the sky are bright because they're close to us. Not Deneb. (lemmy.dbzer0.com)
submitted 2 months ago by Melatonin@lemmy.dbzer0.com to c/casualconversation@lemm.ee
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Hey, my eye just captured some light that, depending on whose measurements are correct, is either as old as the Middle ages, or predates the Christian era.

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[-] mossy_@lemmy.world 4 points 2 months ago

So it's really bright and really far? Presumably 2k+ light years away? I'm more of a "space enthusiast" than a proper astronomer so my knowledge is limited

[-] Melatonin@lemmy.dbzer0.com 3 points 2 months ago

Yeah. It's big and bright and far. There's one other "naked eye" star that's further away, but it's a lot dimmer. Deneb is unique in a lot of ways.

  • Since 1943, its spectrum has served as one of the stable references by which other stars are classified.
  • Deneb is the prototype of the Alpha Cygni (α Cygni) variable stars, whose small irregular amplitudes and rapid pulsations can cause its magnitude to vary anywhere between 1.21 and 1.29.
  • Identifying whether Deneb is currently evolving towards a red supergiant or is currently evolving bluewards again would place valuable constraints on the classes of stars that explode as red supergiants and those that explode as hotter stars.
  • Deneb spent much of its early life as an O-type main-sequence star of about 23 M☉, but it has now exhausted the hydrogen in its core and expanded to become a supergiant.
  • It is one of the largest white 'A' spectral type stars known.

See for yourself!

https://en.wikipedia.org/wiki/Deneb?wprov=sfla1

[-] mossy_@lemmy.world 2 points 2 months ago

Wait how would a star "evolve bluewards again"? I thought when a star fuses all of its smaller elements into heavier ones, it's a one way trip

[-] shinigamiookamiryuu@lemm.ee 2 points 2 months ago

True, but it's Betelgeuse that might go supernova in our lifetime.

And there better not be clouds in the sky like there is any other time there's a show in the sky here, or I might be investing in weather modification.

this post was submitted on 25 Mar 2025
36 points (100.0% liked)

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