A guide to the Pleiades

A guide to M45, also known as the Pleiades, and images of the famous open star cluster.

The Pleiades Stephen Tolley, Liskeard, Cornwall, 19 January 2020 Equipment: Nikon D600 DSLR, Tamron 150-600mm lens, Celestron AVX mount

The Pleiades is probably the most famous star cluster in the sky, prominent with the naked eye and difficult to mistake.

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Located 440 lightyears away, the Pleiades is an open star cluster contained in Charles Messier’s catalogue of clusters and nebulae, the Messier Catalogue, drawn up in 1781, as M45.

In a way this is surprising, because Messier was a comet-hunter and catalogued clusters and nebulae as ‘objects to avoid’ – and there is no chance of confusing the Pleiades with a comet.

Pleiades Seven Sisters in Middlesbrough by Damo Williams, Middlesbrough, UK. Equipment: Nikon d3300, 300mm lens, EQ5 mount
Pleiades Seven Sisters in Middlesbrough by Damo Williams, Middlesbrough, UK. Equipment: Nikon d3300, 300mm lens, EQ5 mount

The nine brightest stars in the Pleiades are concentrated in a field just over one degree across, so they are splendidly shown in binoculars or in a telescope equipped with a wide-angle eyepiece.

With higher magnification only part of the cluster can be shown at any one time, so that the full beauty of the spectacle is lost.

The individual stars of the Pleiades.
The individual stars of the Pleiades.

The Pleiades myth

The Pleiades has been known from very early times and there is no shortage of legends about it.

Also known as the ‘Seven Sisters’, in Greek mythology they were the seven daughters of the giant Atlas and Pleione, daughter of the sea god Oceanus.

Alcyone, Electra, Merope, Maia, Taygete, Calaeno and Asterope (or Sterope). They were walking along, quite peacefully, when they were seen by the huntsman Orion who promptly gave chase.

Zeus, ruler of Olympus, decided to intervene, so he changed the sisters into stars and swung them into the sky, where they remain to this day.

The Pleiades (1885) by the Symbolist painter Elihu Vedder.
The Pleiades (1885) by the Symbolist painter Elihu Vedder.

In 1767, the English clergyman John Michell – a brilliant researcher, too often neglected by modern scientific historians – calculated that the probability of a chance alignment of so many bright stars was only about one in half a million.

When studies were first made of the proper motions of the stars in the Pleiades, it was found that they were all moving across the sky in the same direction at the same rate.

Yet the cluster will not survive indefinitely. Like all galactic clusters it will eventually be dispersed because of the gravitational pull of non-cluster stars.

It should remain identifiable for at least 250 million years, however, so we need be in no hurry to observe it before it merges into the general background.

Although there are only six stars easily distinguishable with the naked eye by people of average sight, the cluster has traditionally been known as the Seven Sisters.

This has led to the legend of the ‘lost Pleiad’, which faded below naked-eye visibility.

The Pleiades by Martin Campbell, Dungannon, Northern Ireland. Equipment: Canon EOS MkII DSLR, Takahashi Epsilon 180mm refractor.
The Pleiades by Martin Campbell, Dungannon, Northern Ireland. Equipment: Canon EOS MkII DSLR, Takahashi Epsilon 180mm refractor.

What type of stars are in the Pleiades?

The main cluster is about 12 lightyears in diameter and contains around 500 stars. The total mass contained is estimated to be about 800 times that of the Sun.

Hot bluish-white stars are dominant. There are no red giants, but there are a number of brown dwarfs – that is to say, objects with less than 8% the mass of the Sun, whose cores have never become sufficiently hot to trigger off nuclear reactions.

There are several white dwarfs, and there is obviously nebulosity, which is brightest in the region of the star Merope.

The nebulosity was discovered in 1859 by the German astronomer Ernst Tempel, using a 4-inch (10cm) telescope, who described it as “a faint stain like a breath on a mirror”.

The Pleiades Stephen Tolley, Liskeard, Cornwall, 19 January 2020 Equipment: Nikon D600 DSLR, Tamron 150-600mm lens, Celestron AVX mount
The Pleiades by Stephen Tolley, Liskeard, Cornwall, 19 January 2020. Equipment: Nikon D600 DSLR, Tamron 150-600mm lens, Celestron AVX mount

The nebula is not particularly elusive – I saw it easily with my five-inch (12cm) refractor – and it is a favourite target for astrophotographers (see our gallery below).

Rather naturally, it was assumed to have been formed at the same time as the Pleiades themselves – but this cannot be so.

The cluster is of the order of 100 million years old, and a reflection nebulae of this kind would long since have been dissipated.

In fact, the explanation is that the stars are simply passing through a dust cloud which happens to lie in their path.

M45 - The Pleiades by Steve Loveridge, Wellington, Somerset, UK. Equipment: Modified Canon 1000d, Astronomik CLS CCD filter, William Optics ZS70, Flattener III, EQMOD controlled HEQ5 Pro, Skywatcher 100ED Pro, QHY5v, PHD.
M45 – The Pleiades by Steve Loveridge, Wellington, Somerset, UK. Equipment: Modified Canon 1000d, Astronomik CLS CCD filter, William Optics ZS70, Flattener III, EQMOD controlled HEQ5 Pro, Skywatcher 100ED Pro, QHY5v, PHD.

How to find the Pleiades

First look for the very familiar constellation of Orion with its two leaders, the orange-red Betelgeuse and the even brighter white Rigel.

The three stars of Orion’s Belt point upwards to Aldebaran, which like Betelgeuse is orange-red; slightly higher up, you will see the Pleiades.

At first they may look like a misty patch, but if conditions are even reasonably good it rapidly becomes evident that they are individual stars, close together.

Orions Belt by John Harding, Sheffield, S. Yorkshire, UK. Equipment: Pentax KR DLSR
Orion’s Belt by John Harding, Sheffield, S. Yorkshire, UK. Equipment: Pentax KR DLSR

Below is a selection of images of the Pleiades captured by BBC Sky at Night Magazine readers and astrophotographers from around the globe.

For advice on imaging the night sky, read our guide to astrophotography or our tutorial on how to photograph stars.

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And don’t forget to send us your images or share them with us via Facebook, Twitter and Instagram.

Pictures of the Pleiades

M45 by John Slinn, Loxwood, West Sussex, UK. Equipment: Miniborg 45ED, 0.85 reducer, unmodified Canon 550D DSLR, Vixen-The Polarie, Manfrotto tripod, 410 geared head.
M45 by John Slinn, Loxwood, West Sussex, UK. Equipment: Miniborg 45ED, 0.85 reducer, unmodified Canon 550D DSLR, Vixen-The Polarie, Manfrotto tripod, 410 geared head.
The Pleiades (M45) by Wayne Stallard, Basildon, Essex, UK. Equipment: Astro-Physics Mach1 GTO mount, William Optics FLT132, Astro-Physics Telecompressor (0.75x) (27TVPH), Starlight Xpress SXVR-M25C CCD camera, Starlight Xpress Lodestar guide camera
The Pleiades (M45) by Wayne Stallard, Basildon, Essex, UK. Equipment: Astro-Physics Mach1 GTO mount, William Optics FLT132, Astro-Physics Telecompressor (0.75x) (27TVPH), Starlight Xpress SXVR-M25C CCD camera, Starlight Xpress Lodestar guide camera
M45 Pleiades Mosiac by David Lawson, Kilgour Observatory, Cincinnati, USA. Equipment: 10
M45 Pleiades Mosiac by David Lawson, Kilgour Observatory, Cincinnati, USA. Equipment: 10″ LX200 ACF, Atik 340L+
M45 by Jamie Bowring, Devon, UK.Equipment: SW150P, HEQ5 Pro Synscan, ST80, LX modded SPC900, PHD, (Modded) EOS 30D with MPCC
M45 by Jamie Bowring, Devon, UK.Equipment: SW150P, HEQ5 Pro Synscan, ST80, LX modded SPC900, PHD, (Modded) EOS 30D with MPCC
M45 The Pleiades by Gordon Speirs, Longton, Preston, UK. Equipment: Nikon D300, Sigma 300mm f2.8 lens, Celestron SE Goto mount.
M45 The Pleiades by Gordon Speirs, Longton, Preston, UK. Equipment: Nikon D300, Sigma 300mm f2.8 lens, Celestron SE Goto mount.
Seven Sisters by Andi Turner, Leek, Staffordshire, UK. Equipment: Takahashi FSQ-85, SXV-H9 mono, HEQ5 mount.
Seven Sisters by Andi Turner, Leek, Staffordshire, UK. Equipment: Takahashi FSQ-85, SXV-H9 mono, HEQ5 mount.
Seven Sisters by Alan Wilkes, Leyland, Lancs, UK. Equipment: Sky-Watcher 114p, Fugifilm Camera
Seven Sisters by Alan Wilkes, Leyland, Lancs, UK. Equipment: Sky-Watcher 114p, Fugifilm Camera
Pleiades by Stephen Dean, Isle of Wight, UK. Equipment: Skywatcher 80mm ED, EQ5 mount, Canon EOS 1100d, CLS filter.
Pleiades by Stephen Dean, Isle of Wight, UK. Equipment: Skywatcher 80mm ED, EQ5 mount, Canon EOS 1100d, CLS filter.
Messier 45 by Bill McSorley, Leeds, UK. Equipment: SW150P, EQ5 GoTo Mount, QHY8L OSC cooled CCD.
Messier 45 by Bill McSorley, Leeds, UK. Equipment: SW150P, EQ5 GoTo Mount, QHY8L OSC cooled CCD.
M45 the Pleiades by James L McConnachie, East Ayrshire, Scotland, UK. Equipment: Williams optics zs70, CGEM mount, Synguider, Badder modded Canon EOS 400d
M45 the Pleiades by James L McConnachie, East Ayrshire, Scotland, UK. Equipment: Williams optics zs70, CGEM mount, Synguider, Badder modded Canon EOS 400d
M45 by Ian Miller, Liverpool, UK. Equipment: William Optics Zenithstar 80ED, Canon EOS 1100D, HEQ5 Pro Mount
M45 by Ian Miller, Liverpool, UK. Equipment: William Optics Zenithstar 80ED, Canon EOS 1100D, HEQ5 Pro Mount
The Seven Sisters by Tom Howard, Crawley, Sussex, UK. Equipment: Nikon D7000, TS 65mm quadruplet refractor, EQ6 mount.
The Seven Sisters by Tom Howard, Crawley, Sussex, UK. Equipment: Nikon D7000, TS 65mm quadruplet refractor, EQ6 mount.
M45 Seven Sisters by Andy Jensen, Battisford, Suffolk, UK. Equipment: Skywatcher 120mm ED Refractor, Canon 600d Modded, NEQ6 Mount.
M45 Seven Sisters by Andy Jensen, Battisford, Suffolk, UK. Equipment: Skywatcher 120mm ED Refractor, Canon 600d Modded, NEQ6 Mount.
M45 - The Pleiades by Bob Franke, Chino Valley, AZ, USA. Equipment: Takahashi 106ED, SBIG STF-8300, Baader filters, Losmandy G11 mount
M45 – The Pleiades by Bob Franke, Chino Valley, AZ, USA. Equipment: Takahashi 106ED, SBIG STF-8300, Baader filters, Losmandy G11 mount
The Pleiades by Robin Durant, Brighton, UK. Equipment: Williams 102MM, Canon 450D.
The Pleiades by Robin Durant, Brighton, UK. Equipment: Williams 102MM, Canon 450D.
The Pleiades by Paul Hardy, Lincolnshire, UK. Equipment: Celestron C6N Reflector, CG5 goto mount, Canon 40d.
The Pleiades by Paul Hardy, Lincolnshire, UK. Equipment: Celestron C6N Reflector, CG5 goto mount, Canon 40d.
M45 Pleiades Star Cluster by Neville Fox, Powys, Wales, UK. Equipment: 12
M45 Pleiades Star Cluster by Neville Fox, Powys, Wales, UK. Equipment: 12″ GSO Newtonian Telescope @ F2.9, focal reducer/coma corrector, EQ6 mount, Fuji S5 Pro.
M45 LRGB by Andy Jensen, Battisford, Suffolk, UK. Equipment: Skywatcher 80mm Equionox, Atik 383l, Neq6
M45 LRGB by Andy Jensen, Battisford, Suffolk, UK. Equipment: Skywatcher 80mm Equionox, Atik 383l, Neq6
NGC1432 Maia Nebula by Mark Griffith, Swindon, UK. Equipment: GSO 8
NGC1432 Maia Nebula by Mark Griffith, Swindon, UK. Equipment: GSO 8″ Richey-Chretien Optical tube, Skywatcher NEQ6 pro mount, Atik 383L+ camera, motorised filter wheel, Astronomik filters.
Blue Birth by Jim Thurston, SE London, UK. Equipment: Canon 5D, 100-400mm lens @ 400mm, guided EQ6.
Blue Birth by Jim Thurston, SE London, UK. Equipment: Canon 5D, 100-400mm lens @ 400mm, guided EQ6.
Pleiades by Chris Isherwood, Kent, UK. Equipment: Skywatcher Evostar 80ED, Canon 1000D
Pleiades by Chris Isherwood, Kent, UK. Equipment: Skywatcher Evostar 80ED, Canon 1000D
M45 - The Pleiades by Trevor Nicholls, Chelmsford, UK. Equipment: QHY8L OSC camera, TS 65 Quad APO, iOptron iEQ45 mount.
M45 – The Pleiades by Trevor Nicholls, Chelmsford, UK. Equipment: QHY8L OSC camera, TS 65 Quad APO, iOptron iEQ45 mount.
Pleiades - M45 by Alastair Woodward, Derby, UK. Equipment: Skywatcher 6
Pleiades – M45 by Alastair Woodward, Derby, UK. Equipment: Skywatcher 6″, unmodded Canon 1000d, CLS clip filter.
M45 Pleiades by Andrea Pistocchini, Germignaga, VA, Italy. Equipment: Tecnosky 80/480, 0,8x reducer, Canon 450D, Neq6-PRO, Skywatcher 70/500, qhy5 II Mono.
M45 Pleiades by Andrea Pistocchini, Germignaga, VA, Italy. Equipment: Tecnosky 80/480, 0,8x reducer, Canon 450D, Neq6-PRO, Skywatcher 70/500, qhy5 II Mono.
M45 Pleiades Seven Sisters by Mark Griffith, Swindon, Wiltshire, UK. Equipment: Teleskop service 8
M45 Pleiades Seven Sisters by Mark Griffith, Swindon, Wiltshire, UK. Equipment: Teleskop service 8″ Boren simon power newtonian, Skywatcher NEQ6 pro mount, Atik 383L+ camera, motorised filter wheel and Astronomik filters.
M45 (The Pleiades) by Trevor Nicholls, Chelmsford, UK. Equipment: TS65 Quad APO, iOptron iEQ45 mount, QHY8L OSC, HuTech IDAS LP filter, OAG, Loadstar X2
M45 (The Pleiades) by Trevor Nicholls, Chelmsford, UK. Equipment: TS65 Quad APO, iOptron iEQ45 mount, QHY8L OSC, HuTech IDAS LP filter, OAG, Loadstar X2
M45 the Pleiades by Chris Duffy, Consett, Co. Durham, UK. Equipment: Canon 1100d, Skywatcher 200p, EQ5 PRO, unguided
M45 the Pleiades by Chris Duffy, Consett, Co. Durham, UK. Equipment: Canon 1100d, Skywatcher 200p, EQ5 PRO, unguided
M45, Pleiades (Merope Nebula) by Chris Heapy, Macclesfield, UK. Equipment: NP127is, 0.8x focal reducer, Losmandy G11, Atik490EX, TV Pronto, SX Lodestar
M45, Pleiades (Merope Nebula) by Chris Heapy, Macclesfield, UK. Equipment: NP127is, 0.8x focal reducer, Losmandy G11, Atik490EX, TV Pronto, SX Lodestar
M45, Pleiades (Merope Nebula) by Chris Heapy, Macclesfield, UK. Equipment: NP127is, 0.8x focal reducer, Losmandy G11, Atik490EX, TV Pronto, SX Lodestar
M45, Pleiades (Merope Nebula) by Chris Heapy, Macclesfield, UK. Equipment: NP127is, 0.8x focal reducer, Losmandy G11, Atik490EX, TV Pronto, SX Lodestar
M45 - The Pleiades by Gavin James, Marlborough, UK. Equipment: Skywatcher 80ED, QSI 683-WSG.
M45 – The Pleiades by Gavin James, Marlborough, UK. Equipment: Skywatcher 80ED, QSI 683-WSG.
M45 by Mariusz, Crawley, UK. Equipment: Pentax K-5, Skywatcher Evostar 80ED Fluorite, Field flattener/reducer, HEQ5Pro unguided
M45 by Mariusz, Crawley, UK. Equipment: Pentax K-5, Skywatcher Evostar 80ED Fluorite, Field flattener/reducer, HEQ5Pro unguided
The Pleiades by David Slack, Prudhoe, Northumberland, UK. Equipment: Revelation ED66 refractor, 0.6 reducer, HEQ5 pro mount, SXV-H9 CCD, ZWO IR block filter 1.25
The Pleiades by David Slack, Prudhoe, Northumberland, UK. Equipment: Revelation ED66 refractor, 0.6 reducer, HEQ5 pro mount, SXV-H9 CCD, ZWO IR block filter 1.25″, Asi120mm finder guider, Canon EOS1100d.
M45 by Colin Thomas. Equipment: Atik camera, Williams Optics telescope
M45 by Colin Thomas. Equipment: Atik camera, Williams Optics telescope
Ice and Fire by Ivaylo Stoynov, Bulgaria. Equipment: Canon 6D (unmodified), Samyang 85mm at f/4, Tak EM-200.
Ice and Fire by Ivaylo Stoynov, Bulgaria. Equipment: Canon 6D (unmodified), Samyang 85mm at f/4, Tak EM-200.
The Pleiades and Hundreds of Galaxies by Ron Brecher, Guelph, Ontario, Canada. Equipment: Moravian G3-16200 EC, Optolong RGB filters, 10
The Pleiades and Hundreds of Galaxies by Ron Brecher, Guelph, Ontario, Canada. Equipment: Moravian G3-16200 EC, Optolong RGB filters, 10″ f/3.6 ASA astrograph, Paramount MX, QHY5, Lumicon 500mm f.l. Achromat, SkyX, FocusMax.
Seven Sisters by Mark Pringle, Northumberland, UK. Equipment: Canon 70D (unmodded), Canon 200mmf2.8, Skywatcher Star Adventurer (no guide).
Seven Sisters by Mark Pringle, Northumberland, UK. Equipment: Canon 70D (unmodded), Canon 200mmf2.8, Skywatcher Star Adventurer (no guide).
Pleiades by Bob Ford, Salisbury, UK. Equipment: SW ED80, HEQ5 Pro Mount (pier mounted), LRGB Baader filters.
Pleiades by Bob Ford, Salisbury, UK. Equipment: SW ED80, HEQ5 Pro Mount (pier mounted), LRGB Baader filters.
M45 - 15MP Mosaic by Simon Todd, Haywards Heath, UK. Equipment: Sky-Watcher EQ8 Pro, Sky-Watcher Quattro 8-CF @ F4, Atik Cameras 383L+ Cooled to -20C, Starlight Xpress Ltd 7x36mm EFW, Baader Planetarium 36mm unmounted LRGB, Celestron Telescopes C80ED, Qhyccd QHY5L-II
M45 – 15MP Mosaic by Simon Todd, Haywards Heath, UK. Equipment: Sky-Watcher EQ8 Pro, Sky-Watcher Quattro 8-CF @ F4, Atik Cameras 383L+ Cooled to -20C, Starlight Xpress Ltd 7x36mm EFW, Baader Planetarium 36mm unmounted LRGB, Celestron Telescopes C80ED, Qhyccd QHY5L-II
M45 - Pleiades by Álvaro Ibáñez Pérez, Las Inviernas, Guadalajara, Spain. Equipment: Takahashi FSQ106EDX refractor, Takahashi EM-400 Temma2, CCD Atik 460EX mono, Baader LRGB, Lunático EZG-60, SXLodestar, RoboFocus, AstroMatic (ftorrev).
M45 – Pleiades by Álvaro Ibáñez Pérez, Las Inviernas, Guadalajara, Spain. Equipment: Takahashi FSQ106EDX refractor, Takahashi EM-400 Temma2, CCD Atik 460EX mono, Baader LRGB, Lunático EZG-60, SXLodestar, RoboFocus, AstroMatic (ftorrev).
M45 - Pleiades - 15MP Mosaic in LRGB by Simon Todd, Haywards Heath, UK. Equipment: SkyWatcher Quattro 8
M45 – Pleiades – 15MP Mosaic in LRGB by Simon Todd, Haywards Heath, UK. Equipment: SkyWatcher Quattro 8″ F/4 Carbon Fibre Newtonian, Skywatcher EQ8 Pro, Celestron C80ED, QHYCCD QHY5II-L, Baader Red 36mm, Baader Luminance 36mm, Baader Blue 36mm, Baader Green 36mm, Starlight Xpress EFW 7x36mm
The Seven Sisters by Rad Djeliov, Northamptonshire, UK. Equipment: Celestron C80ED, Advanced VX mount, Nikon D600.
The Seven Sisters by Rad Djeliov, Northamptonshire, UK. Equipment: Celestron C80ED, Advanced VX mount, Nikon D600.
The Pleiades (M45) by Anne Startup, Carmarthenshire, Wales, UK. Equipment: SXH694 mono CCD, RGB filters, Altair Astro Lightwave 0.6 focal reducer, Altair Astro Wave 102mm triplet refractor, EQ6 mount.
The Pleiades (M45) by Anne Startup, Carmarthenshire, Wales, UK. Equipment: SXH694 mono CCD, RGB filters, Altair Astro Lightwave 0.6 focal reducer, Altair Astro Wave 102mm triplet refractor, EQ6 mount.
M45 Pleiades by Andrew McNaught, Gloucestershire, UK. Equipment: Sky-Watcher ED80, focal reducer, QHY10 CCD, SW EQ8 mount, PhD, SW ST102, Altair mono GPcam.
M45 Pleiades by Andrew McNaught, Gloucestershire, UK. Equipment: Sky-Watcher ED80, focal reducer, QHY10 CCD, SW EQ8 mount, PhD, SW ST102, Altair mono GPcam.
Pleiades Star Cluster by Roger Nicholson, Worthing, UK. Equipment: SkyWatcher 120ED, Canon EOS 750D, Modded, Skywatcher EQ6-R PRO, Synscan Skywatcher 9x50 Finderscope, Skywatcher 0.85x Focal Reducer/Corrector, Evostar-120ED, Incanus Ltd. Astro Photography Tool, Luc Coiffier Deep Sky Stacker 3.3.4, QHYCCD PoleMaster
Pleiades Star Cluster by Roger Nicholson, Worthing, UK. Equipment: SkyWatcher 120ED, Canon EOS 750D, Modded, Skywatcher EQ6-R PRO, Synscan Skywatcher 9×50 Finderscope, Skywatcher 0.85x Focal Reducer/Corrector, Evostar-120ED, Incanus Ltd. Astro Photography Tool, Luc Coiffier Deep Sky Stacker 3.3.4, QHYCCD PoleMaster