Messier 45, Pleiades

History

The Pleiades are the closest to us and therefore the largest appearing galactic star cluster. The six, seven or sometimes more stars visible to the naked eye have been known since the Stone Age. One of the earliest depictions is a cave painting in the «Hall of the Bulls» in the Lascaux cave in France: six points above the neck of an aurochs, estimated age 21'000 to 22'000 years. Also worth mentioning is a representation on the «Nebra Sky Disc», a bronze disc found in Germany from around 1600 BC. Chr. [266]

Messier 45
Messier 45: Pleiades with reflection nebulae; Vixen ED-Apochromat 115 mm, Reducer f/5.2; 3 x 302 s, ISO 1600; Langis 1460 m ü. M.; © 31. 8. 2006 Eduard von Bergen
Messier 45
Messier 45; TEC 140 ED with 0.9x flattner on a AOK Herkules V12 mount, Canon 6D (not modified); 15 x 6 min; Lü Stailas; © 8. 1. 2021 Stefan Berchten
Messier 45
Messier 45: Pleiaden mit Reflexionsnebel; Celestron RASA 11" f/2.22; ZWO ASI6200 Pro; Tentlingen; © 2020 Peter Kocher
Messier 45
Messier 45: Pleiades with reflection nebulae; 500 mm Cassegrain 3625 mm f/7.2; SBIG STL11K; 30+15+15+15 min LRGB; Bernese Highlands; © 2011 Radek Chromik

The star cluster, also known as the «seven stars», has found its way into numerous myths. The best known comes from Greek mythology. The brightest stars are named after the seven daughters of Pleione, the wife of the heavens-bearing titan Atlas: Alkyone, Asterope, Celaeno, Elektra, Maia, Merope and Taygete. They were loved and persecuted by Orion, but never matched. To this day he hurries through the sky night after night without ever catching up with her. [20]

Physical Properties

Messier 45
Messier 45: In visible light (DSS2, top) and infrared (allWISE, bottom) [147]

The star cluster M 45 is about 410 light years away and has at least 250 stars whose affiliation has been confirmed. There are probably many more. The age is estimated to be 20 million years. [4] The whole cluster covers around 2°, about four times the full moon diameter. The nine brightest stars are of type B and enveloped in several reflection nebulae. They focus on an area of just over 1°. The formation looks a bit like a miniature version of the Big Dipper in the constellation Ursa Maior, which is why the cluster has been nicknamed «gummy bear» in the Swiss astronomy scene.

«Revised New General Catalogue and Index Catalogue», «Historically Corrected New General Catalogue», Dr. Wolfgang Steinicke, 2021 [277]
NameRADecTypeBmagVmagDimDreyer DescriptionIdentification
NGC 1432 03 45 49.5+24 22 06RN26.00 × 26.0eF, vL, dif (Maja Plejadum)LBN 772, Maia nebula
NGC 1435 03 46 10.0+23 45 54RN30.00 × 30.0vF, vL, dif (Merope)CED 19I, Merope nebula
IC 349 03 46 20.0+23 56 23RN0.50 × 0.5eF, vS, Pos. 165°, Dist. 36" from MeropeCED 19I, Barnard's Merope nebula

Finder Chart

M 45 is located in the constellation Taurus between the bull's head and the constellation Perseus. The best observation time for this is September to February.

Chart Messier 45
Chart created using SkySafari 6 Pro and STScI Digitized Sky Survey. [149, 160]

Visual Observation

M 45
M 45: Pencil drawing; Borg 125/800 f/6.4 ED Apo; © Jozef Cukas

References

4«Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System» by Robert Burnham; Dover Publications, Inc.; Voume I: ISBN 0-486-23567-X; Volume II: ISBN 0-486-23568-8; Volume III: ISBN 0-486-23673-0
20«Sternbilder und ihre Mythen» von Gerhard Fasching; Zweite, verbesserte Auflage; Springer Verlag Wien, New York; ISBN 3-211-82552-5 (Wien); ISBN 0-387-82552-5 (New York)
147Aladin Lite; aladin.u-strasbg.fr/AladinLite (2020-12-23)
149SkySafari 6 Pro, Simulation Curriculum; skysafariastronomy.com
155PNG Egg; pngegg.com
160The STScI Digitized Sky Survey; archive.stsci.edu/cgi-bin/dss_form
266«The Pleiades: the celestial herd of ancient timekeepers» Amelia Sparavigna; arXiv:0810.1592
277«Historische Deep-Sky Kataloge» von Dr. Wolfgang Steinicke; klima-luft.de/steinicke (2021-02-17)