201115 - M45 "Pleiades" open star cluster ("The 7 Sisters")
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ASTRO:
type=open star cluster; const=Taurus; dist ~ 444 ly size ~ 16 ly IMAGE: location=EB Backyard, BrtlCls=4; exposure=DSLR OSC: 51x120s (1.7h), ISO1600; EQUIPMENT: camera=Nikon D90 (stk); optics=ES102 w 0.8x rdcr, F=571mm, f/5.6; filter=(none); mount=Celestron AVX EQ; guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acqusition=Stellarium, APT, PHD2, processing=Pixinsight, PhotoshopCC, LRCC |
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The Pleiades, also known as "The Seven Sisters", and Messier 45, or M45 and other names by different cultures, is an asterism and open star cluster containing middle-aged, hot blue type B stars in the north-west area of the constellation Taurus. At a distance of about 444 light years, it is among the nearest star clusters to Earth. It is the nearest Messier object to Earth, and is the most obvious cluster to the naked eye in the night sky.
The cluster is dominated by hot blue luminous stars that have formed within the last 100 million years (...being a short period of time by astronomical standards). Reflection nebulae clouds around the brightest stars were once thought to be left over material from their formation, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing. The stars in the cluster are estimated to be moving at a speed of approximately 18 km/s with respect to the clouds.
The name "Seven Sisters" comes from the fact that most naked-eye observers are able to count appx 7 of the brightest stars in the formation. (Some may count more, some less - depending on how "good" their eye-sight is.) Astronomers have actually accounted for 96 stars in the cluster.
Our global culture today is replete with examples of corporations and others seeking to identify themselves through logo's and symbols derived from objects found in the nighttime skies; and, the Pleiades resides near the top of the list. As one of the best examples of this, six (6) of this object's stars in their tightest formation are used today by Subaru Corporation as its logo both corporately and on their cars.
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 pulling in different directions by other objects in the Milky Way galaxy.
The cluster is dominated by hot blue luminous stars that have formed within the last 100 million years (...being a short period of time by astronomical standards). Reflection nebulae clouds around the brightest stars were once thought to be left over material from their formation, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing. The stars in the cluster are estimated to be moving at a speed of approximately 18 km/s with respect to the clouds.
The name "Seven Sisters" comes from the fact that most naked-eye observers are able to count appx 7 of the brightest stars in the formation. (Some may count more, some less - depending on how "good" their eye-sight is.) Astronomers have actually accounted for 96 stars in the cluster.
Our global culture today is replete with examples of corporations and others seeking to identify themselves through logo's and symbols derived from objects found in the nighttime skies; and, the Pleiades resides near the top of the list. As one of the best examples of this, six (6) of this object's stars in their tightest formation are used today by Subaru Corporation as its logo both corporately and on their cars.
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 pulling in different directions by other objects in the Milky Way galaxy.