The Jewel Box, Kappa Crucis Cluster, NGC 4755, is an open cluster in the constellation Crux, originally discovered by Nicolas Louis de Lacaille during 1751-1752. This famous cluster was later named the Jewel Box by Sir John Herschel when he described its telescopic appearance as "a casket of variously coloured precious stones." It is easily visible to the naked eye as a hazy star some 1.0° southeast of the first-magnitude star Beta Crucis. This hazy star (the core of the cluster) was assigned the Bayer star designation Kappa Crucis, from which the cluster takes one of its common names. The modern designation Kappa Crucis has been assigned to one of the stars in the central A-shaped asterism of the cluster, the third brightest cluster star (HD 111973, HIP 62931, HR 4890), located at the base of the right leg of the A. This is a blue supergiant of spectral type B3Iae, shining at the apparent visual magnitude of 5.94. Two other cluster stars are brighter than ? Cru, namely, 5.77 magnitude star HD 111904 (HIP 62894), at the tip of the A, and HD 111613 (HIP 62732) at 5.75, which is 15 arc minutes beyond the asterism toward Beta Crucis.
This cluster is one of the youngest known, with an estimated age of 14 million years. It has a total integrated magnitude of 4.2, is located 6,440 light years from Earth, and contains around 100 stars.
Discovery and observation
The Jewel Box as a star cluster was first determined by Nicolas Louis de Lacaille while he was doing his South African astrometric observations for his star catalogue. He saw the object as a nebulous cluster due to the small aperture of his telescope, but was the first to recognize it as consisting of many stars. The name "Jewel Box" comes from John Herschel's description of it: "...this cluster, though neither a large nor a rich one, is yet an extremely brilliant and beautiful object when viewed through an instrument of sufficient aperture to show distinctly the very different colour of its constituent stars, which give it the effect of a superb piece of fancy jewellery"
Herschel recorded the positions of 100 members of the cluster in 1834-1838.
Cluster In A Box Video
Physical characteristics
The Jewel Box cluster is one of the youngest known open clusters. The mean radial velocity of the Jewel Box cluster is -21 kilometres per second (-13 mi/s). The brightest stars in the Jewel Box cluster are supergiants, and include some of the brightest stars in the Milky Way galaxy.
Calculating its distance is difficult due to the proximity of the Coalsack Nebula, which obscures some of its light.
Observation
The Jewel Box cluster is regarded as one of the finest objects in the southern sky. It is visible to the naked eye as a hazy object of the fourth magnitude. It can be easily located using the star Beta Crucis as a guide, and appears as a fourth magnitude object. It is impressive when viewed with binoculars or a small or large telescopes. The three brightest members of the cluster lie in a straight line known as the 'traffic lights' due to their varying colours.
Gallery
Are You Looking for Products
Here some products related to "Jewel Box (star Cluster)".
Supermicro 2U Cluster-in-..
Amazon.com - Structured W..
Rite Lite LPL641MW Motion..
Amazon.com : HiPo Gen I H..
Get these at Amazon.com* amzn.to is official short URL for Amazon.com, provided by Bitly
Source of the article : here
EmoticonEmoticon