THE DECEPTIVE NGC 411.
Image Credit & Copyright: NASA/ESA Hubble Space Telescope. CLICK photo for larger view and look below for information and links.
If it looks like a duck and quacks like a duck…….it may still not be a duck?!! That’s the case here with NGC 411; a globular….well, an open star cluster roughly 200,000 light years distant in the Small Magellanic Cloud (SMC). Ya, that’s fooled quite a few people over the last year or so because this object looks like one of the 150-ish globular star clusters in the Milky Way galaxy. It’s got the shape (roughly), size, ancient star color etc. but not only is this object not in our galaxy; the stars aren’t even old. Most globular clusters contain stars from 10 to 12 billion years old but the stars here are roughly 1.5 billion years old. That means they aren’t even half the age of the Sun, not even close.
There are exceptions to most rules but in the life of globular star clusters there are simply too many young blue stars here to be a globular. Blue stars are much larger thus burn through their fuel and die quickly. If this were a globular there simply wouldn’t be enough fuel left after the billions of years to create the masses of blue stars here. This is also where the age of this cluster comes is determined as well. By studying the bluest stars in the cluster it’s been determined that an age of 1.5 billion years seems genuine. Which, for all intents and purposes is pretty old for an open cluster.
NAME: NGC 411.
WHAT IS IT?: Open star cluster.
HOW FAR AWAY IS IT?: 200,000 light years.
HOW OLD IS IT?: Approximately 1.5 billion years old.
APPARENT MAGNITUDE?: 12 or +12.
WHERE IS IT? (General): Small Magellanic Cloud (SMC) in the constellation Tucana the toucan.
WHERE IS IT? (Exact RA/DEC J2000): RA 01h 07m 55,95s / DEC -71° 46′ 04,5″.
NASA page on this object: http://www.nasa.gov/mission_pages/hubble/science/ngc411.html
ESA Hubble page on this object: http://www.spacetelescope.org/images/potw1303a/
SIMBAD data page on this object: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+411