Pleiades (Messier 45)

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.a.s.l.; © 31. 8. 2006 Eduard von Bergen
Messier 45
Messier 45: Pleiades with reflection nebulae; 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: Pleiades with reflection nebulae; 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]

Subaru
Subaru: The japanese name for Pleiades. The logo of the famous car manufacturer through the years. The positions of the six stars is no longer accurate since 1980. [155]

Charles Messier added this famous open cluster on 4 March 1769 as 45th object to his famous catalogue. [281] On 19 October 1859 the German astronomer Ernst Wilhelm Leberecht Tempel discovered a nebula (NGC 1435) around the star Merope using his private 4 inch refractor in Venice. On 16 November 1885 the two French brothers Paul and Mathieu Henry found on a plate taken on November 16, 1885 with the 13 inch (f/10) photographic refractor at Paris Observatory another faint nebula around the star Maia, which later was cataloged as NGC 1432. On 14 November 1890 the American astronomer Edward Emerson Barnard noticed on a plate taken with the 36 inch Clark refractor at Lick Observatory another small nebula at 36 arc seconds distance at position 165° from the star Merope, later known as IC 349. In May 1896 the Russian astronomer Vsevolod Viktorovich Stratonov found IC 1990, a very large, much elongated pretty faint nebula of 15 arc minutes lenght. [277]

The formation looks a bit like a miniature version of the Big Dipper in the constellation Ursa Major and also Ursa Minor, which is why the cluster has been nicknamed «gummy bear» by Swiss amateur astronomers. South of the star 25 Tauri (Alcyone) is a chain of six stars nicknamed «Ally's braid» (the flowing locks of Lady Alcyone) by amateur astronomer and musician Stephen Saber. [561]

Physical Properties

Messier 45
Messier 45: Star names, nebulae and star chain «Ally's Braid». Section of the DSS2 [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 star Pleione is a variable whose brightness changes at irregular intervals from 4.83 to 5.38 mag. 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°.

Revised+Historic NGC/IC, Version 22/9, © Dr. Wolfgang Steinicke [277]
NameRADecTypebMagvMagDimDreyer DescriptionIdentification, Remarks
NGC 143203 45 49.5+24 22 06RN26 × 26eF, vL, dif (Maja Plejadum)LBN 772, Maia nebula
NGC 143503 46 10.0+23 45 54RN30 × 30vF, vL, dif (Merope)CED 19I, Merope nebula
IC 34903 46 20.0+23 56 23RN0.5 × 0.5eF, vS, Pos. 165°, Dist. 36" from MeropeCED 19I, Barnard's Merope nebula
IC 199003 47 13.8+24 20 02ENvL, mE pf, 15' lCED 19M

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 Pleiades (Messier 45)
Pleiades (Messier 45) in constellation Taurus. 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

The Pleiades are probably the most conspicuous open star cluster in the night sky. To the naked eye, six to nine stars can be seen, depending on the quality of the sky and the eyes. In binoculars or smaller telescopes they turn out to be a feast for the eyes made of sparkling jewels. With increasing aperture (e.g. from 100 mm), the delicate reflection nebulae also become visible.

More Objects Nearby (±15°)

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
155Subaru Logo; 1000logos.net/subaru-logo (2023-01-08)
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)
281«Catalogue Nébuleuses et des Amas D'Étoiles» Observées à Paris, par M. Messier, à l'Observatoire de la Marine, hôtel de Clugni, rue des Mathurins. «Connoissance des temps ou connoissance des mouvements célestes, pour l'année bissextile 1784 » Page 227; gallica.bnf.fr/ark:/12148/bpt6k6514280n/f235 (2021-02-21)
561Saber Does The Stars; saberdoesthestars.wordpress.com/2011/07/05/saber-does-the-stars (2022-10-13)