Astronomy:NGC 7380

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Short description: Open cluster in the constellation Cepheus
NGC 7380
Wizard Nebula.jpg
NGC 7380 in classic Hubble Palette (Ha/OIII/SII) by amateur astronomer Chuck Ayoub
Observation data (J2000.0 epoch)
ConstellationCepheus
Right ascension 22h 47m 21.0s[1]
Declination+58° 07′ 54[1]
Distance8.5 ± 1.3 kly (2.6 ± 0.4 kpc)[2]
Apparent magnitude (V)7.2
Apparent dimensions (V)25
Physical characteristics
Radius~20 ly (6 pc)
Estimated age4[2] to 11.9 Myr[1]
Other designationsNGC 7380,[3] Sh2-142, Cr 452
See also: Open cluster, List of open clusters

NGC 7380 is a young[4] open cluster of stars in the northern circumpolar constellation of Cepheus, discovered by Caroline Herschel in 1787. The surrounding emission nebulosity is known colloquially as the Wizard Nebula, which spans an angle of 25. German-born astronomer William Herschel included his sister's discovery in his catalog, and labelled it H VIII.77. The nebula is known as S 142 in the 1959 Sharpless catalog (Sh2-142).[2] It is extremely difficult to observe visually, usually requiring very dark skies and an O-III filter. The NGC 7380 complex is located at a distance of approximately 8.5 kilolight-years from the Sun, in the Perseus Arm of the Milky Way.[2]

The cluster spans ~20 light-years (6 pc) with an elongated shape and an extended tail.[2] Age estimates range from 4[2] to 11.9[1] million years. At the center of the cluster lies DH Cephei, a close, double-lined spectroscopic binary system consisting of two massive O-type stars. This pair are the primary ionizing source for the surrounding H II region, and are driving out the surrounding gas and dust while triggering star formation in the neighboring region.[4] Of the variable stars that have been identified in the cluster, 14 have been identified as pre-main sequence stars while 17 are main sequence stars that are primarily B-type variables.[4]

Gallery

References

  1. 1.0 1.1 1.2 1.3 Wu, Zhen-Yu et al. (November 2009), "The orbits of open clusters in the Galaxy", Monthly Notices of the Royal Astronomical Society 399 (4): 2146–2164, doi:10.1111/j.1365-2966.2009.15416.x, Bibcode2009MNRAS.399.2146W. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Chen, W. P. et al. (September 2011), "A Kinematic and Photometric Study of the Galactic Young Star Cluster NGC 7380", The Astronomical Journal 142 (3): 15, doi:10.1088/0004-6256/142/3/71, 71, Bibcode2011AJ....142...71C. 
  3. "NGC 7380". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+7380. 
  4. 4.0 4.1 4.2 Lata, Sneh et al. (March 2016), "Variable stars in young open star cluster NGC 7380", Monthly Notices of the Royal Astronomical Society 456 (3): 2505–2517, doi:10.1093/mnras/stv2800, Bibcode2016MNRAS.456.2505L. 

External links

Coordinates: Sky map 22h 47m 00s, +58° 06′ 00″