About: |
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 right)
5,400 light-years in the distance and M47 (mid-lower left)t 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. [Text from APOD]
|