HUBBLE SPOTS A NURESRY IN OUR SATELLITE GALAXY.
Photo Credit: NASA/ESA Hubble Space Telescope: CLICK photo to view larger size and see below for information and reference links.
Located 210,000 light years away in the constellation Tucana, more specifically one of our satellite galaxies, the Small Magellanic Cloud (SMC) lies this massive region of star formation known as NGC 346 as the 346th entry in the New General Catalog. When it was discovered it had been the first time a population of infant stars had been seen in the SMC. NGC 346 is in reference to the star cluster at the center though it’s often used to describe the entire region in the photo.
Many of these stars at only about half the mass of our Sun; are still undergoing accretion, compression and heating in hopes that they will eventually reach fusion and come to life. That fact is pretty significant it’s very common to see massive star formation through the spiral bands of the Milky Way but in the SMC there’s much less material from previous generations of stars to come together and form a molecular cloud with enough mass to create new stars. The brightest star in the SMC; HD 5980 resides in this region as well.
The crescent shape to this structure and the colors associated with it are a result of the stellar winds (UV radiation) heating and exiting the cloud which renders it aglow. Over time it will also disperse the cloud that birthed it. As the newer stars come to life, this region may become a great bubble of expanding gas as the stars begin to “stretch their legs” if you will. That material will then either re-form another molecular cloud or join smaller pockets of already existing clouds. Either way, that available gas appears to be destined for star creation in the extremely distant future.
In the incredible detail that only Hubble can deliver, we can look into this nebulous star forming region and see that there are approximately 70,000 stars that come in a few different generations. The oldest are second generation stars roughly 4.5 billion years old like our Sun. The younger “protostellar or pre-stellar” generation of stars is only approximately 5 million years old and still undergoing formation as the smaller, lower mass stars take longer to reach fusion. As they continue to use the intersecting dust lanes available to them they should continue to progress and in time ignite the fusion reactions that they need to survive.
NAME: NGC 346.
WHAT IS IT?: Open star cluster within a thick star forming nebula.
HOW BIG IS IT?: The image is approximately 280 light years or 87 parsecs in diameter.
HOW FAR AWAY IS IT?: 210,000 light years or 64,000 parsecs distant.
APPARENT MAGNITUDE?: Approximately 10 or +10.
WHERE IS IT? (General): Constellation Tucana.
WHERE IS IT? (Exact RA/DEC J2000): RA 0h 59m 18s / DEC −72° 10′ 48″.
NASA Hubblesite News Center page for this photo: http://hubblesite.org/newscenter/archive/releases/2005/04/image/a/
ESA Science page for this photo: http://www.esa.int/Our_Activities/Space_Science/Star-forming_region_in_nebula_NGC_346
NASA Astronomy Picture Of the Day (APOD) page for this photo: http://apod.nasa.gov/apod/ap101017.html
ADSABS data page for this object: http://adsabs.harvard.edu/abs/2011AJ….141…31C
ESA Hubble Space Telescope page for this object: http://www.spacetelescope.org/images/heic0514a/
SIMBAD data on this object: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+346
Cornell data on this object: http://arxiv.org/abs/0710.0774