Globular Star Cluster Messier 3

Messier 3 (credit: telescope.org - the Autonomous Robotic Telescope- The Galaxy Camera COAST BVR Filters - The Open University).

Regular visitors to my Blog will remember that, from time to time, I have posted astronomical images I have had taken using a robotic telescope located on Tenerife at altitude on Mount Teide - the third highest volcano on earth. The telescope was formerly managed by Bradford University but is now operated by the Open University. For some time the telescope has been out of operation and the subject of substantial maintenance and replacement. The telescope, camera and mount are being tested and systems refined. About a week ago I found that my requests for imaging objects in the night sky were being actioned and the above image of Messier 3 was in my 'inbox'. The image is a little soft, possibly a focussing error, there were a number of hot pixels and no flat frame was provided but hopefully these issues will be addressed in the near future.

In the meantime I posted this image as I regard Messier 3 one of the most beautiful globular star systems of them all. Can you imagine what it would be like to live on a planet revolving around one of the stars in this cluster?  At night the sky would be bright with  more stars than the eye could resolve or the mind could count.. At the core of the cluster, perhaps day and night would merge?

 Messier 3 -NGC5272- is located in the constellation Canes Venatici (the hunting dogs). It is visible, from a dark sky location through binoculars, as a small blurry patch of light. It can  be found midway on a line drawn between the bright star Arcturus and the less bright but naked eye visible Cor Caroli. I have to say that I find this globular difficult to see through my binoculars from my backyard!  Tripod mounting the binoculars helps!


This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is estimated to be 8 billion years old. It is located at a distance of about 33,900 light-years away from Earth.
Messier 3 is located 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars; by far the highest number found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of –1.34 to –1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered "metal-rich". That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements. Credit Wikipedia