Charles Messier's Butterfly Cluster - Essay Example

Charles Messier's Butterfly Cluster Introduction Our galaxy contains nearly 400 billion stars including many comets, nebulas and star clusters. Star clusters, or Messier objects, are collections of many stars in our galaxy. In the past astronomers confused them with comets; however, Charles Messier (a French scientist) observed them very carefully throughout his life and discovered 15 comets along with 103 other celestial objects which were later named Messier objects. He actually searched for comets and to avoid confusion between comets and Messier objects, he and his colleagues compiled them in a list in 1771. It was a remarkable achievement. The list is known as the Messier Catalog or Messier Object List. The list contains a total of 110 objects. The list contains nebulae, galaxies and star clusters. Body During the process of these observations, the first object they observed was the Crab Nebula (M1). A total of 103 objects were listed by Messier and his colleagues (Burnham 73). The Crab Nebula is a ball of gas left over from a supernova explosion. M2 is a globular cluster of stars in Aquarius, M3 is located in Canes Venatici, and Messier 4 to Messier 7 are located in the constellation of Scorpius. The Butterfly Cluster is Messier 6. This object can be seen by telescope clearly, and in the grayish color by naked eye. The Butterfly Cluster existence was first noticed by Giovanni Battista Hoderna in 1654. Ptolemy discovered it while he was observing M7, and declared it as a part of M7. After that, Phillips Loys de Cheseaux (1945-1946) observed it and recognized it as “a very fine star cluster.” And finally it was catalogued by Charles Messier in 1764 in the list of Messier objects (The Griffith Observer 259). The Butterfly Cluster is an open cluster of stars in the constellation of Scorpius known as Messier 6 or the Butterfly Cluster as it resembles a flying butterfly with open wings and antennae. The stars of the cluster twinkle, and it looks very beautiful in the sky. It is visually a very rewarding object; the butterfly pattern is very visible and obvious. It has been placed in the 6th position in the list of Messier objects. Scorpio is located in the Milky Way and contains many massive objects other than M6 and Messier 7. The Butterfly Cluster has a magnitude of 4.2, an angular diameter of 25 arc minutes, and lies at a distance of 1,600 light years with a luminosity of 8,300 suns. The Butterfly Cluster is about 50 million years old and can be seen in summer nights clearly with binoculars. The objects (M6 and M7) are the summer’s finest and brightest clusters. Different astronomers have different opinions about M6’s age. According to Burnham, it is 100 million years old; WEBDA estimates its age to be around 95 million years, and 51 million years according to the Sky Catalogue 2000.0. Messier objects of the “Messier Summer Chart” are clearly visible on summer nights. Messier objects help astronomers to adjust the distance scale of the universe. The above image shows the view of M6 (outcropped). The image was taken through the Astrograph, Takahashi E-180. How Can It Be Seen? It can be seen about 3/ 1-2 degrees northwest of M7 which is located near the tail of Scorpius. It appears as a hazy patch in the dark sky but it should not be confused with Messier 7. Messier 7 is brighter than Messier 6. M7 is seen in between and the Butterfly Cluster is on its lower side. Messier 6 contains many other Messier objects such as M21, M23, NGC 6167, and NGC 6193. Its magnitude is fainter than M7, and fills the field of 25 angular diameter. One of the ways to find the Butterfly Cluster is to identify the two well-known asterisms of Scorpios and Sagittarius. It has two irregular loops of blue and white stars on both wings and at 40-50x, it has three bright stars in the butterfly’s body. The Butterfly Cluster contains almost 80 stars (Plotner 400) with B type blue (hottest) and K type orange stars (BM Scorpii, HD 160371). The brightest K type orange star is a semi-regular variable star which is the brightest and changes its magnitude from 5.5 to 7 in a period of 28 days. It is in the most left of the four very bright stars and forms a quadrangle along with other stars. All the stars (blue, white and orange) together form a giant molecular cloud and have gravitational force among them, which bounds them together tightly. This cluster can be easily seen in the dark sky. Street lights make it hard to see. Conclusion Our galaxy contains billions of celestial objects which have been classified into different categories based upon their appearance, size and nature of existence. As our understanding of astronomical sciences increases, it is hoped that more and more will become clear about the nature of this cluster of stars. Messier was the first to identify M6, which is commonly known as the Butterfly Cluster. Existing in the constellation of Scorpius, the outline of this cluster of stars resembles the open wings of a butterfly, after which it is named. Containing about eighty stars, this cluster is a mixture of blue and orange type stars. The Butterfly Cluster has remained a subject of study for a considerable period of time, and a number of famous scientists have contributed towards its understanding. It is hoped that a better understanding of the nature of this cluster of stars will contribute towards a deeper insight into the astronomic science as a whole. Works Cited Burnham, Robert. Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System. Vol. 1. S.l..: Dover Publications, 1978. Print. Top of Form Bottom of Form Top of Form Plotner, Tammy. The Night Sky Companion: A Yearly Guide to Sky-Watching, 2008-2009. New York: Springer, 2007. Web. Bottom of Form Top of Form The Griffith Observer. Los Angeles: Griffith Observatory, 1937. Print. Bottom of Form Read More