BEAUTIFULLY DYING STAR ORANGE LIKE A FALL LEAF: WITH A MYSTERY.
Photo credit: Gemini North & South Observatory/AURA: CLICK for large size photo and look below for related link.
Like the dying leaves of a New England Fall; so to do dying stars call our attention to them. This is a photograph of planetary nebula Sh 2-71 and though it’s beautiful, it carries with it a mystery of sorts.
Discovered in 1946 by Rudolph Minkowski, it’s long been believed that the progenitor star to this nebula is the bright star at its center. New data is suggesting that this just might not be the case. The only issue with that is they now don’t know what star created this structure at all.
Let’s start at start: Why is it NOT the bright star in the center? Well, they never said it isn’t….it’s just unlikely. The reason for this is because the star doesn’t appear to be radiating enough high energy ultraviolet light to render the structure aglow as brightly as it is. Then again it’s been determined that a nebula with a structure we see here was likely formed by a binary star system…..which the bright star happens to be. The problem with that is there’s no data on its binary partner. If its partner doesn’t radiate UV radiation at the needed level even this would not suffice. Certainly a little confusing, for sure.
So what are our options for a progenitor if not the bright central star? Well, if you look ever so slightly down and to the right of the bright star you will see a small dim blue star. This star DOES radiate enough high energy ultraviolet light to create the amount of flow in this structure and it’s approximately the right brightness for a star of this nature. However, it does not appear to be a binary system of any sort which is also required to create what we see.
Latest research has suggested that the bright star at center is quite uncommon in that it radiates a strong broad hydrogen-alpha emission which is commonly seen in bright nebula such as this. It has also been determined that the bright star is likely not a chance alignment with the nebula. Conclusion….there isn’t one, but now there’s a suggestion that the whole thing may be a three star system thus, potentially solving the riddle of this odd but beautiful structure.
Gemini North and South Telescopes are twin (Get it?) 8.1 meter ground telescopes; One positioned in Chile and one positioned in Hawaii.
NAME: Sharpless 2-71, SH 2-71.
WHAT IS IT?: Planetary Nebula.
HOW BIG IS IT?: Approximately 230’ X 140” arcseconds on the night sky.
HOW FAR AWAY IS IT?: 1 kiloparsec or approximately 3200 light years distant.
APPARENT MAGNITUDE: A pretty dim 13 or +13.
WHERE IS IT? (General): Constellation Aquila.
WHERE IS IT? (Exact RA/DEC J2000): RA 19h 01m 59.4s / DEC +02d 09’ 19’.
Gemini Observatory page for this object: http://www.gemini.edu/node/11815