w1800 20161030 M45 A7Ra ISO3200 14x30s

The Pleiades, also known as the Seven Sisters and Messier 45, are 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 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 interstellar medium through which the stars are currently passing.
Computer simulations have shown that the Pleiades were 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.

With larger amateur telescopes, the nebulosity around some of the stars can be easily seen; especially when long-exposure photographs are taken. Under ideal observing conditions, some hint of nebulosity around the cluster may even be seen with small telescopes or average binoculars. It is a reflection nebula, caused by dust reflecting the blue light of the hot, young stars.


ObjectM45 - Pleiades incl. NGC1435/1432 Nebulae
Constellation: Taurus
Position: RA 3h 47m 24s DEC +24° 07′ 00″
Apparent Size: 110 arcmin
Apparent Magnitude: +1.6
Distance (average) 444 ly
Photo Datas 
Date 30.10.2016, 20:50 UTC
Location Knottenried/Oberallgäu, 1002m ASL
GPS: 47°36’13“ N, 10°11’24“ E
Sky darkness SQM-L Zenit 20.95mag/sqrsec, Object 20.85mag/sqrsec
Ground Temp./Air Pressure -2.0°C /1035mbar
Thermal sky temp./weather  -52.1°C Zenit
Seeing  6/10
Telescope Canon f/2.8 300mm L IS USM I
Camera Sony A7Ra mod @ T sensor=6.5°C
Expose frames ISO 3200, RAW 14x30s, 5 darks
Total expose
7 min.
Filter no
Mount HPS 10Micron GM 3000
Guiding Cam no
Software DSS 3.3.4, Photoshop CC

C 2016 Peter Cerveny