NGC 1502 (also known as the Golden Harp Cluster) is a young

open cluster An open cluster is a type of star cluster made of tens 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 ...

of approximately 60 stars in the constellation

Camelopardalis Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative form ...

, discovered by

William Herschel Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover ...

on November 3, 1787. It has a

visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of 6.0 and thus is dimly visible to the naked eye. This cluster is located at a distance of approximately from the Sun, at the outer edge of the Cam OB1 association of co-moving stars, and is likely part of the

Orion Arm The Orion Arm, also known as the Orion–Cygnus Arm, is a minor spiral arm within the Milky Way Galaxy spanning in width and extending roughly in length. This galactic structure encompasses the Solar System, including Earth. It is sometimes r ...

. The asterism known as

Kemble's Cascade Kemble's Cascade (designated Kemble 1) is an asterism located in the constellation Camelopardalis. It is an apparent straight line of more than 20 colourful 5th to 10th magnitude stars over a distance of approximately 3 degrees (five moon diamete ...

appears to "flow" into NGC 1502, but this is just a chance alignment of stars. The

Trumpler class An open cluster is a type of star cluster made of tens 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 ...

of NGC 1502 is II3p, indicating poorly populated cluster of stars (p) with a wide brightness range (3). The

main sequence In astronomy, the main sequence is a classification of stars which appear on plots of stellar color index, color versus absolute magnitude, brightness as a continuous and distinctive band. Stars on this band are known as main-sequence stars or d ...

turnoff point The turnoff point for a star refers to the point on the Hertzsprung–Russell diagram where it leaves the main sequence after its main fuel is exhaustedthe main sequence turnoff. By plotting the turnoff points of individual stars in a star clust ...

is not well-defined, so the age estimates range from five to fifteen million years. It is heavily reddened due to

interstellar dust Cosmic dustalso called extraterrestrial dust, space dust, or star dustis dust that occurs in outer space or has fallen onto Earth. Most cosmic dust particles measure between a few molecules and , such as micrometeoroids (30 μm). Cosmic dust can ...

. One of the brightest candidate members of the cluster is the

eclipsing binary A binary star or binary star system is a Star system, system of two stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved ...

SZ Cam, which is a component of a visual

double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a ...

ADS 2984. There are eleven

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

s and four candidate variables among the cluster members, including a β Cep, two periodic B-type variables, 2–3 eclipsing variables, and an RR Lyrae star. Five members of the cluster are chemically peculiar.

References

External links

* * __NOTOC__ {{DEFAULTSORT:NGC 1502

1502 Year 1502 ( MDII) was a common year starting on Saturday of the Julian calendar. Events January–March * January 1 – Portuguese explorers, led by Gonçalo Coelho, sail into Guanabara Bay, Brazil, mistaking it for the mouth of ...

Camelopardalis Discoveries by William Herschel Open clusters

See also

References

External links