| 词条 | Messier 41 | |||
| 释义 |
| name = Messier 41 | image = |caption= Messier 41 is seen 4 degrees south of Sirius in Canis Major | epoch = J2000 | class = Open cluster | ra = {{RA|06|46.0}}[1] | dec = {{DEC|-20|46}}[1] | dist_ly = 2,300 ly[3] | dist_pc = 710 pc | appmag_v = 4.5[1] | size_v = 38 arcmin[1] | mass_kg = | mass_msol = | radius_ly = 12.5 ly | v_hb = | age = 190 million yrs[2] | constellation = Canis Major | notes = | names = M41,[1] NGC 2287[1] }}Messier 41 (also known as M41 or NGC 2287) is an open cluster in the constellation Canis Major. It was discovered by Giovanni Batista Hodierna before 1654 and was perhaps known to Aristotle about 325 BC.[3] M41 lies about four degrees almost exactly south of Sirius, and forms a triangle with it and Nu2 Canis Majoris—all three can be seen in the same field in binoculars. The cluster itself covers an area around the size of the full moon.[4] It contains about 100 stars including several red giants, the brightest being a spectral type K3 giant of apparent magnitude 6.3 near the cluster's center, and a number of white dwarfs.[5][6][7] The cluster is estimated to be moving away from us at 23.3 km/s.[8] The diameter of the cluster is between 25 and 26 light years. 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.[2]Walter Scott Houston describes the appearance of the cluster in small telescopes:[9]
See also
References1. ^1 {{cite web |title=Messier Object 41 |work=SEDS |url=http://messier.seds.org/m/m041.html |accessdate=2009-12-10}} 2. ^1 {{cite book|last1=Stoyan|first1=Ronald|title=Atlas of the Messier Objects: Highlights of the Deep Sky|date=2008|publisher=Cambridge University Press|isbn=9780521895545|page=171|url=https://books.google.com/?id=x2VuBAAAQBAJ&pg=PT559&dq=messier+41+age#v=onepage&q=messier%2041%20age&f=false|accessdate=9 July 2015}} 3. ^M41 possibly recorded by Aristotle 4. ^{{cite book|last=Kambic|first=Bojan |title=Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore|publisher=Springer|location=New York, New York|date=2009|pages=230|isbn=978-0387853550|url=https://books.google.com/?id=3vxLNPNHOcwC&pg=PA230&dq=Sirius+%22M+41%22#v=onepage&q=Sirius%20%22M%2041%22&f=false}} 5. ^Koester, D. Reimers, D. (1981), "Spectroscopic identification of white dwarfs in Galactic Clusters I. NGC2287 and NGC3532", Astronomy & Astrophysics, 99, L8-11 6. ^{{cite book|last=De Laet|first=Rony |title=The Casual Sky Observer's Guide: Stargazing with Binoculars and Small Telescopes|publisher=Springer|location=New York, New York|date=2011|pages=95–97|isbn=978-1461405955|url=https://books.google.com/?id=3fhBelJk-30C&pg=PA95&dq=Messier+41#v=onepage&q=Messier%2041&f=false}} 7. ^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 8. ^1 2 3 4 5 {{cite simbad | title=M 41 | accessdate=2006-12-21}} 9. ^{{cite book | last = Houston | first = Walter Scott | date = 2005 | title = Deep-Sky Wonders | pages= | publisher = Sky Publishing Corporation | isbn = 978-1-931559-23-2}} External links{{WikiSky}}
6 : Open clusters|Canis Major|Messier objects|NGC objects|Orion–Cygnus Arm|Astronomical objects known since antiquity |
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