The Small Sagittarius Star Cloud
|Field of View:||25.1° x 37.7°|
|Exposure:||4 x 30sec, f1.8, ISO4000.|
|Camera:||Canon 60D, 35mm lens.|
This is Messier 24, which is the only star cloud in the Messier List. It can be seen in the above image of the galactic centre, which I took with my DSLR camera in 2014. It’s somewhat of a mystery why Messier included this star cloud on his 18th century list of fuzzy objects which were not comets. Most of them are globular clusters, galaxies, planetary nebulae or open star clusters.
My Sky Safari app describes M24 as “a pseudo-cluster of stars spread thousands of light years along our line of sight, perceived through a ‘tunnel’ in the Milky Way’s interstellar dust.”
It is actually “a section of a far interior spiral arm of our galaxy, the Norma Spiral Arm, which we see framed by the dust clouds of the nearer Sagittarius-Carina Spiral Arm.”
The following wonderful public domain map of the Milky Way Galaxy, by Cmglee, shows where we are (red dot) and shows the two above-mentioned spiral arms located between us and the central galactic bar. Note that the coordinates in the diagram are based on the Solar System, not the Milky Way.
After amateur astronomers acquire their first serious telescope, many become a bit obsessed with picking out as many of the Messier objects visible from their latitude as possible. Most could be viewed through an eyepiece within the first twelve months.
I followed the same path – but since I stopped using an eyepiece and moved into astro-imaging, I found that ticking objects off a list by imaging them is a much slower business!
I’ve set myself an eventual target of posting images on Cosmic Focus all of the Messier and Caldwell objects that I can, a total of 219 objects (not all of which are visible here).
This image from six years ago brings me up to 72 Messier/Caldwell objects imaged. 🙃