M45 - The Pleiades
M45 - The Pleiades is an open star cluster located around 444 light years away in the constellatin Taurus, the Bull. With an apparent visual magnitude of 1.6, this cluster is a prominent object in the Northern Hemisphere during the winter. Being among the nearest star clusters to us here on Earth, it is very easy to see with the naked eye in the night sky. This cluster contains middle-aged, hot, blue B-type stars that are extremely luminous and have formed over the last 100 million years. The blue reflection nebulosity associated with M45 is known to be from an unrelated dust cloud in the interstellar medium through which this cluster is actively passing. It is estimated that this cluster will stay together for about 250 million more years, then will disperse from the gravitational interactions with its galactic neighbors.
Galileo Galilei was the first astronomer to view the Pleiades through a telescope and discovered the cluster has many stars that are too dim to be seen with the naked eye. His sketch from March 0f 1610 shows 36 stars. Charles Messier measured the position of the cluster and included it in his catalogue published in 1771. In 1782, Edme-Sebastien Jeaurat drew a map showing 64 stars of the Pleiades from his 1779 observations, then published it in 1786.
Named for the Seven Sisters of Greek mythology, along with their parents, the nine brightest stars of the Pleiades are: Sterope, Merope, Electra, Maia, Taygeta, Celaeno, Alcyone, Atlas and Pleione, respectfully.
Other designations: Messier 45, Seven Sisters, Melotte 22, and Maia Nebula (lesser known)
- Telescope: Stellarvue SV80S Apo @ f/6
- Accessories: Stellarvue SFF3 flattener; Dew control by Dew Buster; Alnitak Flat-Man
- Mount: Takahashi EM-200 Temma2
- Camera: QSI683wsg-8 CCD @ -25C
- Guiding: Starlight Xpress Lodestar via PHD
- Filters: Astrodon E-Series Gen II LRGB filters
- Exposure: 14 x 15min. binned 1x1 Luminance; 6 x 10min. binned 2x2 in each R, G, & B
- Acquisition: ImagesPlus 5.0 Camera Control
- Processing: PixInsight 1.8
- Date(s): December 12 & 20, 2014
- SQM reading (begin - end): N1:20.52 – 20.64; N2:20.63 – 20.68
- Temperature (begin - end): N1:31.5ºF – 26.6ºF; N2:31.6ºF – 24.8ºF
- Capture conditions: N1: transparency = Above Avg 4/5, seeing = Good 4/5; N2: transparency = Average 3/5, seeing = Average 3/5
- Location: Portland, TN, USA
M45PleiadesSeven Sistersclusternebulareflectionopen star clusteropen clusterstar clusterMessierMessier 45
From Reflection & Emission Nebulae