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Messier 38

Open cluster in the constellation Auriga

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Messier 38 or M38, also known as NGC 1912 or Starfish Cluster, is an open cluster of stars in the constellation of Auriga. It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Guillaume Le Gentil in 1749. The open clusters M36 and M37, also discovered by Hodierna, are often grouped together with M38. Distance is about 1.066 kpc (3,480 ly) away from Earth. The open cluster NGC 1907 lies nearby on the sky, but the two are most likely just experiencing a fly-by, having originated in different parts of the galaxy.

01Description

The cluster's brightest stars form a pattern resembling the Greek letter Pi or, according to Webb, an "oblique cross". Walter Scott Houston described its appearance as follows:

Photographs usually show a departure from circularity, a feature quite evident to visual observers. Older reports almost always mention a cross shape, which seems more pronounced with small instruments. A view with a 24-inch reflector on a fine Arizona night showed the cluster as irregular, and the host of stars made fruitless any effort to find a geometrical figure.

At its distance of 1066 pc., its angular diameter of about 20 arc minutes corresponds to about 4.0 parsecs (13 light years), similar to that of its more distant neighbor M37. It is of intermediate age at about 290 million years. From the population of about 100 stars, this open cluster features a prominent yellow giant with the apparent magnitude +7.9 and spectral type G0 as its brightest member. This corresponds to an absolute magnitude of -1.5, or a luminosity of 900 Suns. For comparison, the Sun would appear as a faint magnitude +15.3 star from the distance of M38.

02Components

NAMERight
ascension
DeclinationSpectral
Type
HD 3551905h 26m 54.32s+35° 27' 26.2K2
NGC 1912 HOAG 2B5II-III
NGC 1912 HOAG 3
NGC 1912 HOAG 405h 28m 35.39s+35° 52' 51.2'A0V
NGC 1912 HOAG 505h 28m 50.73s+35° 46' 47.2A0Vn
NGC 1912 HOAG 605h 28m 10.46s+35° 55' 26.0A0:V
NGC 1912 HOAG 705h 28m 34.25s+35° 53' 29.7A2V
NGC 1912 HOAG 11
NGC 1912 HOAG 19K2IIIb
NGC 1912 HOAG 104G5III
NGC 1912 SS G2
NGC 1912 HOAG 128K0III
NGC 1912 SS G4A5:V
NGC 1912 HOAG 153K0V
NGC 1912 SS G3A3V
NGC 1912 HOAG 160K1IV
NGC 1912 HOAG 161G5V
NGC 1912 HOAG 171G7IV
NGC 1912 HOAG 172
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Sources and credits

This article is adapted from the Wikipedia article Messier 38, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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