Messier 47 is an open cluster in the Puppis constellation named after Charles Messier. The two types of star clusters are Globular clusters and Open clusters. While Globular clusters are located in the halo of a galaxy, Open clusters are generally located in the disk. Also, Open clusters only contain up to thousands of stars while Globular clusters can contain hundreds of thousands. M47 only contains about 50 stars within a region with a diameter of 12 light years and it has a distance of approximately 1,600 light years. The brightest star in the cluster is of spectral class B2 and mag 5.7. Also, according to The Sky Catalog 2000 it is approximately 78 million years old and is receding from us at 9 km/sec. M47 was first discovered by Giovanni Batista Hodierna before 1654 but this fact remained unknown until 1984. Charles Messier then discovered M47 on February 19, 1771. However, Messier made a mistake when computing its position and it was considered missing until 1959 when it was identified by T.F. Morris.
The M47 cluster was initialy too large to be captured in a single photo and the image above is actually a mosaic of four black and white photos blended together to make a single clear image. In the image the six largest stars as well as a large number of smaller stars are grouped together to form a clear cluster. These are the brighter stars in the image but there are a multitude of even smaller stars which fill the background. On account of the nature of the image, it difficult to tell exactly which of these smaller stars are part of the cluster. Even though M47 is a very young star cluster it is still fairly old as is evident by the lack of dust which exists around newly formed clusters. M47 has a linear size of approximately 15 lightyears. Although a large amount of information can be taken from just a rudimentary overview of this image of M47, it is difficult to note certain facts because of the deceptive nature of two-dimensional images.
Frommert, Hartmut and Kronberg, Christine. "Messier 4.7" seds.org. 2007 Aug. 30. Accessed 19 Apr. 2011. <http://seds.org/messier/m/m047.html>
Bennet, Jeffrey, Donahue, Megan, Schneider, Nicholas, Voit, Mark. the essential Cosmic Perspective. pp. 326-328. 2007. Pearson Addison-Wesley. 1301 Sansome St., San Francisco, CA 94111. Accessed 19 Apr. 2011.
|Right Ascension (J2000)||07:36:36|
|Filters used||C (Clear)|
|Exposure time per filter||C (5s x 10) in each quadrant|
|Date observed||March 25, 2011 UT|