M45 – Pleiadi
The Pleiades (also known as the Seven Sisters and Messier 45, are an open star cluster containing middle-aged, hot starts 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 cluster is dominated by hot blue and luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from the formation of the cluster, but are now considered likely to be an unrelated dust cloud in the intersellar medium through which the stars are currently passing.
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 name of the Pleiades comes from Ancient Greek. It probably derives from plein (“to sail”) because of the cluster’s importance in delimiting the sailing season in the Mediterranean Sea: “the season of navigation began with their heliacal rising”. However, in mythology the name was used for the Pleaides, seven divine sisters, the name supposedly deriving from that of their mother Pleione and effectively meaning “daughters of Pleione”. In reality, the name of the star cluster almost certainly came first, and Pleione was invented to explain it.
- Costellation: Tourus
- AR: 03h 47m 00s – DEC: +24° 07′ 00″
- Distance: 443 ly
- Age: 100 Ml years
- Optics: Takahashi FSQ85ED
- Mount: EQ6 Skywatcher
- Camera: QSI 683 WSG-5
- Accessories: Lodestar, USB_Focus V3
- Cooling: -20°C
- Filters: Astrodon Tru-Balance E-Series Gen 2 HaLRGB
- Exposure: LRGB bin1 600″x300″x300″x300″x300″ [23x17x15x14]
- Flat-Dark-Bias: 15-19-201
- Integration: 7.7 h
- Date: December 10/12th, 2018
- Location: Own remote observatory
- SQM-L: 21.10
- Software: PHD2, Voyager, Pixinsight, PS