December 14, 2019

Astro-Event of the Week; March 2nd-8th, 2009; Hind’s Crimson Star.

The astro-challenge for this week is a very special sort of variable star… I give you Hind’s Crimson Star in the constellation Lepus, the Hare. Looking for something unique to impress folks with at the next star party? Carbon stars are the sure ticket for oohs and ahhs! In addition to crimson, the adjectives “ruddy”, “blood” and “wine” red (as in good Merlot!) come to mind when observing this star. And there are only a handful of really good ones! First noted by English variable star observer extraordinaire John Russell Hind in 1845, R Leporis (Its technical name) is also a noted to fluctuate in brightness from magnitudes +5.5 (bright enough to see with the naked eye under dark skies) to a minima of +11.7 over a period of 432 days. Currently, R Leporis is coming off of a long maximum…do you note a change in redness as it fades? Typically, a change in hue from coppery orange to ruby red is perceived… let us know what you see! At the foot of Orion, its home constellation of Lepus is well placed for evening observation in both hemispheres over the next few months. The coordinates of Hind’s Crimson Star are;

Right Ascension: 04 hours, 59.6′

Declination: -14į 48′

This weeks’ astro-term of the week is Carbon Star. These are divided into two types: Classical, C-R/C-N stars, which are large red giants of off the main sequence towards the end of their lives, and non-classical C-J/C-H stars, which are main sequence binary stars being fed by a small companion, usually a degenerate (not an implication of ones’ moral compass in astrophysics!) white dwarf. R Leporis is of the classical, C-N spectral variety; it fuses helium nuclei into beryllium and again into carbon, emitting a gamma ray and an alpha particle (another helium nucleus) in the process. All of this carbon ash accumulates in the stars’ outer atmosphere, giving it a pretty ruddy color. Soon (soon being maybe 10 million years or so!) R Leporis will undergo a catastrophic Helium flash, and then it’s all over. As it sheds copious amounts of material into space, R Leporis (and our Sun!) †is destined to spend its final days as a wispy planetary nebula with a cooling white dwarf nestled at its heart. And on goes this game of ours…

Comments

  1. mridul ganguly says:

    please give some important ideas about india astronomy

  2. webmaster says:

    Off of the top of my head, I know that India recently sent a probe to the Moon, has one of the highest observatories on Earth in Kashmir, and I believe there is one of the telescopes in the GONG network based on the subcontinent, as well. we could potentially do a post about “Indian Astronomy” if there is enough interest!

Trackbacks

  1. [...] I give you Hindís Crimson Star in the constellation Lepus, the Hare. Looking for something unique to impress folks with at the next star party? Carbon stars are the sure ticket for oohs and ahhs! In addition to crimson, the adjectives …Continue Reading… [...]

  2. [...] Notes: Hindís Crimson Star. [...]

  3. [...] Moon were all big hits. We even performed a small feat of visual athletics and successfully located Hindís Crimson Star to the delight of our [...]

  4. [...] the carbon star. Fans of this space will recall our exploits tracking down such favorites as Hindís Crimson Star, UU Aurigae, and V Hydrae. These ruddy stars come as a welcome surprise in the often monotone [...]

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