Wednesday, November 30, 2011

R Leporis

I took my first visual variable star measurement of R LEP last night and was blown away by its deep red color. It was truly mesmerizing - I just wanted to keep staring at it. It was easy to see that it was dimmer than the 7.4 comp on the chart but R LEP was clearly all about R LEP.

That led me on a search to learn more about it, and found some great information posted by Jim Kaler, Professor emeritus of Astronomy at the Univeristy of Illinois [Link]. Here are some interesting tidbits from his article:

  • R LEP is a "carbon star," accounting for its deep red color. 
  • Carbon stars are among the coolest known.
  • Carbon stars are rare, and most far away. At a distance of about 1100 light years R Leporis is one of the closer. 
  • R LEP has a temperature of only 2245 to 2290 Kelvin and luminosity of between 5200 and 7000 Suns (almost all coming out in the infrared)
  • R LEP has a whopping radius between 480 and 535 times that of the Sun, or between 2.2 and 2.5 Astronomical Units.
  • Once the envelope is ejected, the hot core will light the surrounding wind in a "planetary nebula" and will then finally expire as a cooling, fairly massive white dwarf akin to Sirius B. 
  • Much of the carbon (and many other chemical elements) of the Universe came from such stars that died off long before the Sun was born 4.5 billion years ago, including that from which life is made.

No comments:

Post a Comment

Please comment - there's lots of room - after all, "The universe is a big place, perhaps the biggest." (Kilgore Trout)