Messier 52 or M52, also known as NGC 7654 or the Scorpion Cluster, is an open cluster of stars in the highly northern constellation of Cassiopeia. It was discovered by Charles Messier in 1774.[3][a] It can be seen from Earth under a good night sky with binoculars. The brightness of the cluster is influenced by extinction, which is stronger in the southern half.[6] Its metallicity is somewhat below that of the Sun, and is estimated to be [Fe/H] = −0.05 ± 0.01.[7]

Messier 52
Open cluster Messier 52 in Cassiopeia
Observation data (J2000 epoch)
Right ascension23h 24m 48.0s[1]
Declination+61° 35′ 36″[1]
Distance4.6 kly (1.4 kpc)[1]
Apparent magnitude (V)7.3[2]
Apparent dimensions (V)13.0[3]
Physical characteristics
Mass1,200 M[4] M
Radius9.5 ly[3]
Estimated age158.5 Myr[1]
Other designationsNGC 7654, Cr 455, C 2322+613, OCl 260[5]
Associations
ConstellationCassiopeia
See also: Open cluster, List of open clusters

R. J. Trumpler classified the cluster appearance as II2r, indicating a rich cluster with little central concentration and a medium range in the brightness of the stars.[8] This was later revised to I2r, denoting a dense core.[6] The cluster has a core radius of 2.97 ± 0.46 ly (0.91 ± 0.14 pc) and a tidal radius of 42.7 ± 7.2 ly (13.1 ± 2.2 pc).[4] It has an estimated age of 158.5 million years[1] and a mass of 1,200 M.[4]

The magnitude 8.3 supergiant star BD +60°2532 is a probable member of the cluster,[4] so too 18 candidate slowly pulsating B stars, one being a Delta (δ) Scuti variable, and three candidate Gamma Doradus (γ Dor) variables.[9] There may also be three Be stars.[10] The core of the cluster shows a lack of interstellar matter, which may be due to supernovae explosion(s) early in the cluster's history.[6]

See also

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References and footnotes

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  1. ^ a b c d e 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, arXiv:0909.3737, Bibcode:2009MNRAS.399.2146W, doi:10.1111/j.1365-2966.2009.15416.x, S2CID 6066790.
  2. ^ "Messier 52". SEDS Messier Catalog. Archived from the original on 1 July 2022. Retrieved 29 April 2022.
  3. ^ a b c Adam, Len (2018), Imaging the Messier Objects Remotely from Your Laptop, The Patrick Moore Practical Astronomy Series, Springer, p. 241, Bibcode:2018imor.book.....A, ISBN 978-3319653853
  4. ^ a b c d Bonatto, C.; Bica, E. (September 2006), "Methods for improving open cluster fundamental parameters applied to M 52 and NGC 3960", Astronomy and Astrophysics, 455 (3): 931–942, arXiv:astro-ph/0608022, Bibcode:2006A&A...455..931B, doi:10.1051/0004-6361:20065315, S2CID 16118935
  5. ^ "M 52". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 28, 2018.
  6. ^ a b c Pandey, A. K.; et al. (August 2001), "NGC 7654: An interesting cluster to study star formation history", Astronomy and Astrophysics, 374 (2): 504–522, Bibcode:2001A&A...374..504P, doi:10.1051/0004-6361:20010642.
  7. ^ Akbulut, B.; Ak, S.; Yontan, T.; Bilir, S.; Ak, T.; Banks, T.; Kaan Ulgen, E.; Paunzen, E. (2021). "A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data". Astrophysics and Space Science. 366 (7). arXiv:2107.03462. doi:10.1007/s10509-021-03975-x. S2CID 235765696.
  8. ^ Trumpler, Robert Julius (1930), "Preliminary results on the distances, dimensions and space distribution of open star clusters", Lick Observatory Bulletin, 420: 154–188, Bibcode:1930LicOB..14..154T, doi:10.5479/ADS/bib/1930LicOB.14.154T.
  9. ^ Luo, Y. P.; et al. (February 2012), "Discovery of 14 New Slowly Pulsating B Stars in the Open Cluster NGC 7654", The Astrophysical Journal Letters, 746 (1): 5, Bibcode:2012ApJ...746L...7L, doi:10.1088/2041-8205/746/1/L7, L7.
  10. ^ Bond, Howard E. (August 1973), "Be Stars in the Galactic Cluster M 52", Publications of the Astronomical Society of the Pacific, 85 (506): 405, Bibcode:1973PASP...85..405B, doi:10.1086/129477.
  1. ^ September 7
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