A STAR SENDING SMOKE SIGNALS OF ITS OWN DEMISE
Photo By: NASA/ESA Hubble Space Telescope. CLICK photo for full size and see below for links.
Ok so maybe smoke signals is stretching it too far, but for this near death carbon star it may as well be its last breaths. Star U-Camelopardalis or “U-Cam” for short is a star that’s nearing the end of the road in its journey of existence. Quickly becoming more and more unstable as it uses up its fusion resources it had started coughing up spherical shells of material out into the surrounding cosmos. Data suggests that this event is taking place every few-thousand years or so. This shell that we see here was created approximately 700 years ago and is expanding at approximately 45 meters per second.
What you are looking at in this Hubble photo is a bright central star surrounded by a beautifully spherical shell of its own material. To me it almost resembles an evolved dandelion before the wind blows away its seeds into the air. You may have picked up on the term carbon star so let me explain. A carbon star is a star whose atmosphere contains higher quantities of carbon than oxygen. You see, in the core hydrogen to helium fusion has ceased and helium is fusing to create carbon. The massive pressure and heat in the core now interacts with the helium outside the core (Yep, even in dying stars there’s hydrogen and helium left in the star, unusable to the core to continue its life though). And fusion of helium into carbon is taking place outside of the core, creating these beautiful shell-like structures.
NAME: U Camelopardalis, U Cam, SAO 12870, HD22611.
WHAT IS IT?: Red Giant & Carbon Star near death.
HOW FAR AWAY IS IT?: Approximately 1400 light years distant.
APPARENT MAGNITUDE?: About 7.35 so just beyond naked eye viewing.
WHERE IS IT? (General): Northern constellation of Camelopardalis, the “Giraffe” and along side the un-official asterism of Kemble’s Cascade.
WHERE IS IT? (Exact RA/DEC J2000): RA 03h 41m 48.17s / DEC +62° 38′ 54.39”.
ESA Hubble Space Telescope page for this image: http://www.spacetelescope.org/images/potw1227a/
Star Observer page for U Cam: http://www.starobserver.eu/multiplestars/ucamelopardalis.html
AAVSO Star Plotter: http://www.aavso.org/vsp
Carbon Star Observing Program: http://www.astroleague.org/content/carbon-star-observing-program
AstroSurf carbon stars list: http://www.astrosurf.com/buil/us/peculiar2/carbon.htm