by APOD Robot » Tue Apr 03, 2012 4:06 am
M46 and M47: Star Clusters Young and Old
Explanation: Many stars form in
clusters. Galactic or
open star clusters are relatively young swarms of bright stars
born together near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two
nice examples are M46 (upper left) 5,400 light-years in the distance and M47 (lower right) only 1,600 light-years away toward the nautical constellation
Puppis. Around 300 million years
young M46 contains a few hundred stars in a region about 30 light-years across. Aged 80 million years,
M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. But
this portrait of stellar youth also contains an ancient
interloper. The small, colorful patch of glowing gas in
M46 is actually the
planetary nebula NGC 2438 - the final phase in the life of a sun-like star
billions of years old.
NGC 2438 is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46.
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[url=http://apod.nasa.gov/apod/ap120403.html][img]http://apod.nasa.gov/apod/calendar/S_120403.jpg[/img] [size=150]M46 and M47: Star Clusters Young and Old[/size][/url]
[b] Explanation: [/b] Many stars form in [url=http://asterisk.apod.com/viewtopic.php?f=24&t=18009]clusters[/url]. Galactic or [url=http://www.seds.org/messier/open.html]open star clusters[/url] are relatively young swarms of bright stars [url=http://universe-review.ca/F06-star-cluster.htm]born together[/url] near the plane of our Milky Way Galaxy. Separated by about a degree on the sky, two [url=http://apod.nasa.gov/apod/ap111007.html]nice examples[/url] are M46 (upper left) 5,400 light-years in the distance and M47 (lower right) only 1,600 light-years away toward the nautical constellation [url=http://hawastsoc.org/deepsky/pup/index.html]Puppis[/url]. Around 300 million years [url=http://www.seds.org/messier/m/m046.html]young M46[/url] contains a few hundred stars in a region about 30 light-years across. Aged 80 million years, [url=http://www.seds.org/messier/m/m047.html]M47 is a[/url] smaller but looser cluster of about 50 stars spanning 10 light-years. But [url=http://www.baskies.com.ar/PHOTOS/M46%20M47%20LRGB%20HR.htm]this portrait[/url] of stellar youth also contains an ancient [url=http://icanhascheezburger.files.wordpress.com/2010/01/funny-pictures-cat-has-an-intruder.jpg]interloper[/url]. The small, colorful patch of glowing gas in [url=http://apod.nasa.gov/apod/ap090326.html]M46[/url] is actually the [url=http://apod.nasa.gov/apod/ap030614.html]planetary nebula[/url] [url=http://apod.nasa.gov/apod/ap110407.html]NGC 2438[/url] - the final phase in the life of a sun-like star [i]billions[/i] of years old. [url=http://www.seds.org/messier/xtra/ngc/n2438.html]NGC 2438[/url] is estimated to be only 3,000 light-years distant and likely represents a foreground object, only by chance appearing along our line of sight to youthful M46.
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