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Open Star Cluster(NGC 1342) & Open Star Cluster(NGC 272)
Corry Remy & Brianna Johnson

NGC 1342 NGC 272
NGC 1342 - Corry Remy NGC 272 - Brianna Johnson

In the beginning, a Molecular Cloud created a star cluster. The Molecular Cloud said, “let there be Light, and the stars shone forth with great luminosity.” Now the star clusters were formed in community because molecular clouds are composed of a multitude of solar masses of material. After the remaining gas heated and blew away, these formed objects were joined together by gravity, and the Spirit of the Molecular Cloud was hovering over their burning surfaces. Some of these stars may have reached the escape velocity from their protocluster and fell, to be forever classified as the stars who “ran away”; the other more holy stars will be bound together by the Holy Gravity and live the duration of their existence, in union, orbiting one another. The memory of the Molecular Cloud saw this, and saw that this was good. Following, the Molecular Cloud’s spirit gave a name to the young cluster, saying that it will be named an Open Cluster because it is hot and luminous. The Molecular Cloud’s spirit placed luminous blue and yellow stars within the cluster to exemplify to the rest of the universe that the cluster was young and made up of O, B and A stars. The Molecular Cloud’s spirit saw all that it had made, and it was very good. And there were stars, and there was dark matter--for millions of years. (University of Oregon)

William Herschel discovered NGC 1342 on December 28, 1799. (Seligman) However, although it was discovered during the eighteenth century, the cluster as a whole is estimated to be around 450 millions years old. Interestingly, that is not old for a cluster; it is actually pretty young--hence why the cluster is referred to as an open cluster. It is approximately 17 arcminutes in size and is estimated to be around 1,170 light years away. The highlight of the structure is a horizontal line of prominent stars that cross through the center. (This line is constructed of stars with magnitudes of 7, 8 and 9.) This line is more prominent within other documented pictures of the cluster because the stars are bright blue and yellow, affirming that the cluster is both extremely hot and young. One significance of this horizontal line is that it proves that the cluster has no concentrated core. The cluster is located within the constellation Perseus, named after the greek hero who is most famous for slaying Medusa (through the power of eye contact, Medusa would turn people into stone).

Speaking of Perseus, later on in life he used Medusa’s head to turn a sea monster into stone in order to save the virtuous Andromeda from either being sacrificed by her parents in order to appease Neptune or being consumed by the sea monster. If you’re wondering, Andromeda married Perseus, and they lived happily ever after. Within this happy ever after, Andromeda was given a constellation to forever bear her name. Located in this constellation, interestingly, is the star cluster NGC 272 (the image located to the right). NGC 272 (also called OCL 312)  was discovered by a man named Heinrich d’Arrest, a German- Danish astronomer, on August 2, 1864. (Seligman) The cluster was found using a 27.94 cm f/17.5 Merz refractor at the Copenhagen Observatory. NGC 272 has a magnitude of 8.5 and approximately 5.0 arcminutes in size. A special feature of the cluster is that it has one very large bright blue star in its center. The rest of its cluster is made up by some less hot, bright yellow stars.  

After reading the aforementioned data, one may conclude that the clusters have similarities and differences. For starters, both clusters are alike in the facts that: (1) they both are classified as open clusters; therefore, both are constructed of mostly blue and yellow stars, affirming that both are younger clusters. (2) Both are found within constellations that are connected through their mythological ancestry.

In contrast, both vary greatly in size--NGC 1342 is three times larger than NGC 272. However, that is not the only area in which NGC 272 is lagging behind NGC 1342 in. The age of NGC 272 is unknown, making the fact that NGC is classified as 450 million years old that much cooler. However, it might not be that amazing in comparison to the ages of all open star clusters, because a study was done in 2015 (Astronomers conducted research on the ages of Red Giants in open star clusters: NGC 1342, 1662, 1912, 2354 and 2447) which concluded that the creation of star clusters was common 450 million years ago.(Reddy) Although this information may cause a loss in brownie points for NGC 1342, it still is not as bad as what is about to be revealed about NGC 272: according to a study done by a group of astronomers in 2010, NGC 272 might not properly fit the classification of a star cluster! The astronomers were doing a study on old star clusters which had begun to degenerate when they came upon NGC 272 and deduced that it might be better categorized as a “field fluctuation,” or a small part of space which varies from its surrounding environment. Accordingly, the astronomers reckon that NGC 272 might simply be a random organization of stars (most commonly referred to as an asterism). (Pavani)

References:

Ayiomamitis, Anthony. "NGC 1342 Open Cluster in Perseus ." Astronomy Magazine . N.p., 15 Nov. 2009. Web. 2 Dec. 2015. <http://cs.astronomy.com/asy/m/starclusters/432457.aspx>

Pavani, D.B. "Diagnostic Tool to Analyse Colour–magnitude Diagrams of Poorly Populated Stellar Concentrations." Web. 9 Dec. 2015.

Reddy, A. B. S., S. Giridhar, and D. L. Lambert. "Comprehensive Abundance Analysis of Red Giants in the Open Clusters NGC 1342, 1662, 1912, 2354 and 2447." Monthly Notices of the Royal Astronomical Society (2015): 4301-322. Cornell University Library. Web. 9 Dec. 2015.

Seligman, Courtney. "New General Catalog Objects: NGC 250 - 299." New General Catalog Objects: NGC 250 - 299. 2015. Web. 2 Dec. 2015.

"Star Clusters." University of Oregon . . Web. 2 Dec. 2015. <http://abyss.uoregon.edu/~js/ast122/lectures/lec15.html>.

 

 

Object NGC 1342 NGC 272
Right Ascension (J2000) 03:31:40 00:51:25
Declination (J2000) +27:22:27 +35:49:18
Filters used B (Blue), R (Red), V (Green) B (Blue), R (Red), V (Green)
Exposure time per filter B (300s x 2), V (180s x 2), and R (120s x 2) B (300s x 2), V (180s x 2), and R (120s x 2)
Image dimension 1092x736 pixels; 23.8x16.1 arcminutes 407x304 pixels; 8.8x6.5 arcminutes
Date/time observed September 29, 2015, 09:15 UT September 28, 2015, 03:26 UT

 

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