NGC 6231
Encyclopedia
NGC 6231 is an open cluster
located near Zeta Scorpii
. Zeta1 (HR 6262)
is a member of this star cluster.
(Its brighter apparent partner, Zeta2 (HR 6271), is only 150 ly from Earth and so is not a cluster member.)
This cluster is estimated about 3.2 million years old, and is approaching the Solar System
at 22 km/s. Very young stars including it, belong to the Scorpius OB1 association. Zeta1 Scorpii (spectral type O8 and magnitude 4.71.) is the hottest star in it.
It was discovered by Giovanni Batista Hodierna before 1654. Hodierna listed it as Luminosae in his catalogue of deep sky observations. This catalogue was included in his book De Admirandis Coeli Characteribuse published in 1654 at Palermo.
It was independently observed by other astronomers after Hodierna.
Open cluster
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist...
located near Zeta Scorpii
Zeta Scorpii
The Bayer designation Zeta Scorpii is shared by two stars in the constellation Scorpius:* ζ¹ Scorpii * ζ² Scorpii...
. Zeta1 (HR 6262)
is a member of this star cluster.
(Its brighter apparent partner, Zeta2 (HR 6271), is only 150 ly from Earth and so is not a cluster member.)
This cluster is estimated about 3.2 million years old, and is approaching the Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
at 22 km/s. Very young stars including it, belong to the Scorpius OB1 association. Zeta1 Scorpii (spectral type O8 and magnitude 4.71.) is the hottest star in it.
It was discovered by Giovanni Batista Hodierna before 1654. Hodierna listed it as Luminosae in his catalogue of deep sky observations. This catalogue was included in his book De Admirandis Coeli Characteribuse published in 1654 at Palermo.
It was independently observed by other astronomers after Hodierna.
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