Bellatrix Orionis

Image Credits X-ray: NASA/CXC/PSU/K. Getman et al.; IRL NASA/JPL-Caltech/CfA/J. Wang et al.

This fantastic image of Cepheus B is a composite of data from the Chandra X-ray Observatory and the Spitzer Space Telescope.  It shows a molecular cloud within our galaxy which is  about 2,400 light years from Earth.  Within this region there is cool interstellar gas and dust which was left over from the formation of the galaxy and mostly contains molecular hydrogen.

The data from Chandra has enabled astronomers to find young stars near and within Cepheus B as they were able to identified them by their strong x-ray emissions.  The data gleaned from Spitzer further enabled the astronomers to ascertain if any of the young stars had proto-planetary disks around them.  Such disks only exist in very young systems where planets are still forming, therefore there presence can be used as an indication of the age of a star system.

The current thinking is that star formation in Cepheus B is triggered by radiation for one bright massive star (HD217086), which is outside the molecular cloud. For further information visit Chandra

Image Credit: NASA/JPL-Caltech

The image on the right of comet Holmes was taken by the Spitzer Space Telescope in March 2008.  5 months previously the comet had brightened incredibly.

Once very 6 years comet 17P/Holmes travels towards the Sun from the area of Jupiter.  It always follows the same route and usually this occurs without incident.  But during the last 116 years comet Holmes has twice exploded, once in November 1892 and the second time in October 2007.  On both occasions it exploded as it reached the asteroid belt.  As yet astronomers have offered no explanation as to why this happened.