Friday, December 26, 2014

Orion & The Seven Sisters – StarLog_12/25/2014


Over Christmas night there were clear skies in Oklahoma and I was able to try my hand at some real astrophotography.  Messier objects are famous in the world of amateur astronomy and make up the best examples of the five types of deep sky objects (DSOs): diffuse nebulae, planetary nebulae, open clusters, globular clusters and galaxies.  The French astronomer Charles Messier was a renowned comet hunter who was frustrated by objects in the night sky that were not comets, so he made a list of everything the he deemed a distraction.  His catalog was completed in the late 1700s and contains over 100 astronomical objects.  The other night I took my first pictures of M42 and M45.

M42 also known as the Orion Nebula is a diffuse nebula in the constellation Orion.  After the Big Dipper, it ranks as the second most distinctive constellation in the night sky.  During the winter Orion, the mythical hunter, takes center stage in the southern skies.  Orion’s belt is what allows the star group to be so recognizable, nowhere else in the nights sky are three bright stars so well aligned.


Orion’s Belt and the Orion Nebula (M42) shot on a tripod using my Canon EOS Rebel T5i, EF 70-300 mm f/4-5.6 IS USM, f/4.0, 15 sec, ISO 800 in southern Oklahoma.
 
My first photograph contains the lower half of the constellation Orion.  The three bright stars in alignment seen in the upper left make up Orion’s belt.  Where as the pink diffuse nebula in the center is M42, also known as the Orion Nebula. 


Close up of the Orion Nebula (M42) shot on a tripod using my Canon EOS Rebel T5i, EF 70-300 mm f/4-5.6 IS USM, f/5.6, and 6.0 sec, ISO 1600 in southern Oklahoma.

The pinkish blur in the center of Orion is the real gem.  M42 is so cool because it is in the same arm as us in the Milky Way Galaxy but happens to be 1,344 light years distant.  This diffuse nebula is a stellar nursery and is one of the best examples of star birth.  Also, this stellar nursery is BIG, 24 light years across big.  The bright center contains a very young open cluster, known as the Trapezium.  This tight cluster of stars is responsible for much of the illumination in the Nebula.  As a whole, M42 contains more than 2,000 stars.  If you let your eyes adjust on a dark night you should be able to see this great cloud of gas and dust with your naked eye.

Working your way north from Orion leads you to another stellar wonder, the Pleiades, or the Seven Sisters (M45).  This open star cluster is one of the closest to us and being so makes it the most visible to the naked eye.  The Pleiades have had some sort of impact on almost all cultures going back to antiquity.  They were even used as a sort of ancient eye exam; it was a sign of keen eyesight if you could resolve at least seven of the stars.


The Pleiades, or the Seven Sisters (M45) shot on a tripod using my Canon EOS Rebel T5i, EF 70-300 mm f/4-5.6 IS USM, f/4.5, and 10.0 sec, ISO 1600 in southern Oklahoma.
 

Motion blur of the Pleiades, or the Seven Sisters (M45) shot on a tripod using my Canon EOS Rebel T5i, EF 70-300 mm f/4-5.6 IS USM, f/4.0, and 15.0 sec, ISO 1600 in southern Oklahoma.
  
The cluster is roughly 16 light years in diameter and contains over 1,000 confirmed stars.  Forming within the last 100 million years it is thought that the cluster was formed from a compact stellar cloud of gas and dust similar to the Orion Nebula.  Located only a short 440 light years away we can expect to have a clear view of this stellar wonder for another 250 million years before they rip themselves apart under the force of their own gravity.


Basic layout and structure of our region of the Milky Way Galaxy.  The Sun is located in the outer regions of the Orion Arm and the Orion Nebula is located south east of the sun while the Pleiades is located just south of the sun. Image taken from Terence Dickinson’s Nightwatch: A practical Guide to Viewing the Universe.









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