Globular Clusters

June 16, 2017

Thanks to Alissa Simon, HMU Tutor, for today's post.

This is the second of three posts about astronomy. (Last week's post can be found here.) In today's post, we will trace a little bit of the ideas and theories behind contemporary astronomy and also introduce a Charles Messier as well as globular cluster (M 5). Today's image depends upon equipment newly made available to amateur astronomers. In fact, much of contemporary astronomy depends upon the mechanical aid of telescopes and computers. These machines enable humans to look past what the naked eye can see. They have also greatly changed the conversation surrounding astronomy.

Astronomy has always posed questions about humanity's size and existence in comparison to the heavens. It has also consistently focused on observation. However, aside from those similarities, astronomy has greatly changed in theory, application and acceptance. We currently accept that the earth revolves around the sun, but this was not always the case. Understanding that earth is a planet with similar matter as heavenly bodies revolutionized the study of astronomy. Copernicus' proposal seemed absurd at the time, since the details did not correspond to observable reality. As humanity slowly grew to accept Copernican ideas, they also began to refute Aristotle's emphasis on sense-experience. In other words, establishing that earth is part of a much larger system that we cannot directly observe changes human understanding of truth. Sensory data is unreliable in terms of astronomy. Furthermore, Adler notes in the Syntopicon that the changing awareness of heavenly bodies was perhaps even more radical. He writes, “[T]he unification of nature which Kepler began and Newton completed, when set against Aristotle's physics, may be even more radical.” That matter on earth can correspond to the same rules as bodies in outer space simultaneously reinforced humanity's smallness while changing any understanding of space as a container for religious or spiritual beings.

These theories continued to evolve and be proven correct through data. Adler notes, “[A]stronomy has one peculiar feature which distinguishes it from other branches of mathemetical physics. It is empirical rather than experimental. The astronomer does not control the phenomena.” This important point leads us into some present-day astrological tools. As instrumentation advanced, astronomers kept copious notes and catalogs of their data. This has turned into helpful data for other astronomers and also amateur astronomers. Any interested person can now access many of these tools online. Most require a telescope, but a number of them are even visible to the naked eye.

One helpful tool comes from French astronomer Charles Messier. While, Messier was originally searching for comets, he noted over 100 objects that impeded or confused his view of comets. These objects are now labeled a variety of nebula, clusters, and galaxies. Messier (with the help from his contemporaries) took note of the placement of these anomalies in the sky. These objects have become popular viewing items and even received names and labels. In last week's post, we shared Richard Johnson's images of M 31, M 101 and M 51, which used the Messier numbering system. These items correspond to objects discovered in the Messier catalog. The accessibility and improvement of telescopes has given rise to the Messier Catalog's popularity. There is even a spring Messier marathon for the more serious astronomer. Another helpful website even organizes the catalog according to object.

The following photo is of globular cluster M 5. Merriam-Webster defines globular cluster as “any of various approximately spherical clusters of gravitationally associated stars that typically populate galactic halos.” helps ascertain the meaning and importance of globular clusters. They write, “Globular clusters are densely packed collections of ancient stars. Roughly spherical in shape, they contain hundreds if not thousands, and sometimes millions, of stars. Studying them helps astronomers estimate the age of the universe or figure out where the center of a galaxy lies.”

Globular Cluster M 5. Image credit: Richard Johnson.

Globular Cluster M 5. Image credit: Richard Johnson.

Richard Johnson, amateur astronomer, writes that, “the globular cluster M 5 (NGC 5904) is located in the constellation Serpens and is one of the finest globular clusters in the sky. M 5 is estimated to be 13 billion years old, making it one of the oldest globular clusters in the Milky Way Galaxy. M 5 is estimated to be about 24,500 light years from Earth. The cluster contains more than 100,000 stars and perhaps up to 500,000 stars according to some estimates. M 5 is one of the larger globular clusters known, spanning 165 light years across.”

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