CHANDRA & SPITZER TEAM UP TO CAPTURE STAR FORMATION IN CEPHEUS B
Image Credit & Copyright: X-ray (NASA/CXC/PSU/K. Getman et al.); IR (NASA/JPL-Caltech/CfA/J. Wang et al.). CLICK image for larger view and look below for great information and all related links.
This image is a combined Chandra X-ray Observatory/Spitzer Space Telescope image and it’s of the massive molecular cloud 2400 light years away known as Cepheus B. This mass of star forming molecular hydrogen was likely created with the formation of the galaxy and thanks to a nearby friend is pumping out stars efficiently.
Stars within this objects “inner layer” are roughly one million years old and even more amazing is that the data gleaned from Spitzer shows us that 70-80% of these stars contain protoplanetary disks around them. Protoplanetary or pre-planetary disks are young stars with disks of material left over from stellar formation. That material may be used to create planetary systems or will be blown off into the surrounding universe. Many inner layer stars haven’t had time yet to completely free themselves by blowing off the surrounding molecular cloud that created them. If you look to the bottom of this image you can see one young star beginning to clear out its surrounding area.
Just outside of the molecular cloud is the “intermediate-layer” and its stars here are roughly 2-3 million years old and thus the protoplanetary disk population is, as predicted, a much less 60% in this area. These stars have pretty much cleared the surrounding material away from themselves so they are now free to view the universe.
As you reach out away from the molecular cloud even further, stars here in the “outer-layer” these 3-5 million year old stars that were created within Cepheus B have even fewer protoplanetary disks; remaining around only about 30% pf these stars. Most star systems by the time they reach this age are well underway in the formation of planets and dispersing the excess material that the star hasn’t used up.
It’s believed that the star formation within this cloud was kicked off by the massive radiation from a star outside this region cataloged as (HD217086). The star can be seen annotated in the online version in the links below. If you would like to try your hand at a little star hopping it can be seen here too, you just have to know how to find it. Let’s start at the tip of this structure, look to your left and you can see a small triangle or pyramid of three brighter stars. The star on the left appears purple and the other two are green/white. The top star in this pyramid or the one closest to the purple looking star is HD217086. That is the more distant star that’s believed to have disrupted this cloud and caused it to then get into the business of star formation through a process known as Radiation Driven Implosion (RDI).
HD217086 is a bright blue main sequence multiple star system in Cepheus with an apparent magnitude of about 7.6.
NAME: Cepheus B.
WHAT IS IT?: Molecular cloud and star forming region.
HOW FAR AWAY IS IT?: 2400 light years.
HOW BIG IS IT?: Roughly 15’ arcminutes on the night sky.
WHERE IS IT? (General): Constellation Cepheus.
WHERE IS IT? (Exact RA/DEC J2000): RA 22h 56m 46.99s / Dec +62° 40′ 0.0012″
Chandra X-ray Observatory page for this image: http://chandra.harvard.edu/photo/2009/cepb/
Spitzer Space Telescope page for this image: http://www.spitzer.caltech.edu/images/2719-ssc2009-17a-Trigger-Happy-Cloud
SIMBAD data page on star HD217086: http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+217086