M45 - The Pleiades Star Cluster

In astronomy, the Pleiades or Seven Sisters (Messier 45 or M45), is an open star cluster containing middle-aged hot B-type stars located in the constellation of Taurus. It is among the nearest star clusters to Earth and is the cluster most obvious to the naked eye in the night sky. The celestial entity has several meanings in different cultures and traditions.

The cluster is dominated by hot blue and extremely luminous stars that have formed within the last 100 million years. Dust that forms a faint reflection nebulosity around the brightest stars was thought at first to be left over from the formation of the cluster (hence the alternate name Maia Nebula after the star Maia), but is now known to be an unrelated dust cloud in the interstellar medium, through which the stars are currently passing. Computer simulations have shown that the Pleiades was probably formed from a compact configuration that resembled the Orion Nebula. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighborhood.

The cluster contains over 1,000 statistically confirmed members, although this figure excludes unresolved binary stars. The distance to the Pleiades can be used as an important first step to calibrate the cosmic distance ladder. As the cluster is so close to the Earth, its distance is relatively easy to measure and has been estimated by many methods. [source wikipedia]

This picture was taken in 7th Meeting Brazilian of Astrophotography in July, 2014 - Alto Paraíso de Goiás - Chapada dos Veadeiros - Goiás - Brazil.

Technical data
ISO 800, total exposure of 02h50m (34 subs), darks, flats and biases applied.

Equipment
- Equatorial Mount Orion Atlas EQ-G
- Auto guided with Orion Starshoot and Refractor Orion 80mm
- Refractor Triplet Meade 80mm APO F6
- Canon DSLR 500D modded with Astrodon Filter
- Astro-Tech Field Flattener 2"

Software
Capture: BackyardEOS
Processing: PixInsight 1.8 and Adobe Photoshop CS5

Ps: Stars's spikes were created by crossed wire in front of refractor!