Astronomy:Messier 41

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Short description: Open cluster in the constellation Canis Major
Messier 41
M41-noao.jpg
Open cluster Messier 41 in Canis Major
Observation data (J2000 epoch)
ConstellationCanis Major
Right ascension 06h 46.0m[1]
Declination−20° 46′[1]
Distance2,300 ly[2] (710 pc)
Apparent magnitude (V)4.5[1]
Apparent dimensions (V)38 arcmin[2]
Physical characteristics
Radius12.5 ly
Estimated age190 million yrs[3]
Other designationsM41,[1] NGC 2287[1]
See also: Open cluster, List of open clusters

Messier 41 (also known as M41 or NGC 2287) is an open cluster in the constellation Canis Major, sometimes referred to as The Little Beehive Cluster.[4] It was discovered by Giovanni Batista Hodierna before 1654 and was perhaps known to Aristotle about 325 BC.[5] It lies about four degrees almost exactly south of Sirius, with which it forms a roughly equilateral triangle with Nu2 Canis Majoris to the west—all three figure in the same field in binoculars.[6]

The cluster covers an area about the size of the full Moon.[6] It contains about 100 stars, including several red giants the brightest of which has spectral type K3, apparent magnitude 6.3 and is near the center, and some white dwarfs.[7][8][9] The cluster is estimated to be moving away from us at 23.3 km/s.[1] The diameter of the cluster is 25–26 light-years (7.7–8.0 pc). It is estimated to be 190 million years old, and cluster properties and dynamics suggest a total life expectancy of 500 million years for this cluster, before it will have disintegrated.[3]

Walter Scott Houston describes the appearance of the cluster in small telescopes:[10]

Many visual observers speak of seeing curved lines of stars in M41. Although they seem inconspicuous on photographs, the curves stand out strongly in my 10-inch [reflecting telescope], and the bright red star near the center of the cluster is prominent.

The bright red/orange star near the center is HIP 32406, a giant star of spectral type K2, about 1500 ly away of magnitude 6.9.

Gallery

  • Center 2MASS/NASA

  • M41 in an 8" telescope

  • Sirius and M41 (lower right), M50 (upper left), and NGC 2360 (lower left)

  • M41 finder chart

  • Open cluster M41 taken from a 12-inch Dobson telescope in Viña del Mar

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "M 41". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=M+41. 
  2. ↑ 2.0 2.1 "Messier Object 41". SEDS. http://messier.seds.org/m/m041.html. 
  3. ↑ 3.0 3.1 Stoyan, Ronald (2008). Atlas of the Messier Objects: Highlights of the Deep Sky. Cambridge University Press. p. 171. ISBN 9780521895545. https://books.google.com/books?id=x2VuBAAAQBAJ&pg=PT559. 
  4. ↑ The Dog Star and the Little Beehive Cluster
  5. ↑ M41 possibly recorded by Aristotle
  6. ↑ 6.0 6.1 Kambic, Bojan (2009). Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore. New York, New York: Springer. pp. 230. ISBN 978-0-387-85355-0. https://books.google.com/books?id=3vxLNPNHOcwC&pg=PA230. 
  7. ↑ Koester, D. Reimers, D. (1981), "Spectroscopic identification of white dwarfs in Galactic Clusters I. NGC2287 and NGC3532", Astronomy & Astrophysics, 99, L8-11
  8. ↑ De Laet, Rony (2011). The Casual Sky Observer's Guide: Stargazing with Binoculars and Small Telescopes. New York, New York: Springer. pp. 95–97. ISBN 978-1-4614-0595-5. https://books.google.com/books?id=3fhBelJk-30C&pg=PA95. 
  9. ↑ Dobbie, P, Day-Jones, A, Williams, K, Casewell, S, Burleigh, M, Lodieu, N, Parker, Q, Baxter, R, (2012), "Further investigation of white dwarfs in the open clusters NGC2287 and NGC3532", Monthly notices of the Royal Astronomical Society, 423, 2815–2828
  10. ↑ Houston, Walter Scott (2005). Deep-Sky Wonders. Sky Publishing Corporation. ISBN 978-1-931559-23-2. 

External links


Coordinates: Sky map 06h 46.0m 00s, −20° 46′ 00″



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