Thursday, November 7, 2013

ω Centauri Globular Cluster

Beyond the Milky Way

There are few clear nights in Bogotá, and the nights of this sketch were some of those. Until these nights I had not explored the southern skies much, but a few nights before this sketch, I had noticed a bright spot of considerable size close to the area of the Southern Cross.
The nights of December 21 and 22 of 2012 I decided to sketch.  It was not difficult to find it with the binoculars (they provide a fantastic field of view of 4.4° enough to perform a quick scan of the area in a few minutes) and thanks to the good apparent magnitude of 3.7 and very dense core (the visible part from LP skies) size of approximately 1/2 of the full moon or about 15 arc min. the cluster was easy to spot.  Going from Gacrux to the east for ±13 degrees, I found a bright oval considerable in size so then I started to sketch, but knowing nothing about this DSO that I could perceive as a very tiny star just visible with the naked eye.
Until now, together with M42 and M45, this is the only DSO visible to the naked eye in my light polluted skies (I have never seen the megallenic clouds from the latitude I live in). Also this is the brightest and largest DSO I have ever seen from Bogotá and even if it only rises at 25° above the horizon and is severely affected by the LP, It shines as the Andromeda Galaxy which goes beyond 40° above the horizon and therefore is less affected by the LP.

After I had performed this sketch based on a raw sketch of pencil on yellow notebook paper, I read some information about it. Previously, described in Ptolomeo’s Almagesto as a star and posteriorly (designed in Bayer’s star atlas Uranometria, omnium asterismorum with the Greek letter Ω, this DSO became part of the “stars” in Centauri just as any naked eye observer would see it. It was rediscovered by Edmund Halley in 1677 who for the first time described its nature as non-stellar. Most of the information about it says that Omega Centauri is a cluster orbiting our milky way and could be the “leftovers” of a dwarf galaxy disrupted and absorbed by our galaxy, but in some way it is ironic to say that Omega Cluster is not part of our Galaxy because it has been part of our galaxy from Ptolomeo and the stargazers of his time and even before.

Enjoy the sketch!


Edited by Jennifer Steinberg (editor in chief)


1 comment:

  1. I think it is really neat to sketch first and research later. It makes the second look at the object even better! Great drawing and representation!