Messier 26
| Messier 26 | |
|---|---|
 Open cluster Messier 26 Credit: Hillary Mathis, Vanessa Harvey, REU program/NOIRLab/NSF/AURA | |
| Observation data (J2000.0epoch) | |
| Right ascension | 18h45m18.0s[1] |
| Declination | −09° 23′ 00″[1] |
| Distance | 5,160ly(1,582pc)[2] |
| Apparent magnitude(V) | 8.0[3] |
| Apparent dimensions (V) | 14′[3] |
| Physical characteristics | |
| Radius | 11 ly[4] |
| Estimated age | 85.3[1]million years |
| Other designations | Messier 26,NGC6694,[5]Cr389, C 1842-094 |
| Associations | |
| Constellation | Scutum |
Messier 26,also known asNGC 6694,is anopen clusterofstarsin the southernconstellationofScutum.It was discovered byCharles Messierin 1764.[a]This 8th magnitude cluster is a challenge to find in ideal skies with typicalbinoculars,where it can be, with any modern minimum 3-inch (76 mm)aperturedevice. It is south-southwest of the open clusterMessier 11and is14′across.[3]About 25 stars are visible in a telescope with a 150–200 mm (6–8 in) aperture.[6]
M26 spans a linear size of 22[4]light yearsacross with atidal radiusof 25 light-years,[7]and is at a distance of 5,160[2]light yearsfrom theEarth.The brightest star is ofmagnitude11[6]and the age of this cluster has been calculated to be 85.3[1]million years. It includes one knownspectroscopic binarysystem.[8]
An interesting feature of M26 is a region of lowstardensity near the nucleus. A hypothesis was that it was caused by an obscuring cloud ofinterstellar matterbetween us and the cluster, but a paper byJames Cuffeysuggested that this is not possible and that it really is a "shell of low stellar space density".[9]In 2015, Michael Merrifield of the University of Nottingham said that there is, as yet, no clear explanation for the phenomenon.[10]
Gallery
[edit]-
Map showing the location of M26 (Roberto Mura)
See also
[edit]Footnotes and references
[edit]Footnotes
[edit]- ^On June 20
References
[edit]- ^abcdWu, 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,S2CID6066790.
- ^abKharchenko, N. V.; et al. (2005), "Astrophysical parameters of Galactic open clusters",Astronomy and Astrophysics,438(3): 1163–1173,arXiv:astro-ph/0501674,Bibcode:2005A&A...438.1163K,doi:10.1051/0004-6361:20042523,S2CID9079873.
- ^abcThompson, Robert; Thompson, Barbara (2007),Illustrated Guide to Astronomical Wonders: From Novice to Master Observer,DIY science, O'Reilly Media, Inc., p. 431,ISBN978-0596526856
- ^abKharchenko, N. V.; et al. (March 2009), "Shape parameters of Galactic open clusters",Astronomy and Astrophysics,495(3): 807–818,arXiv:0812.3542,Bibcode:2009A&A...495..807K,doi:10.1051/0004-6361/200810407,S2CID2196805.
- ^"M 26".SIMBAD.Centre de données astronomiques de Strasbourg.RetrievedNovember 15,2018.
- ^abBurnham, Robert (1978),Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System,Dover books on astronomy, vol. 3, Courier Corporation, p. 1756,ISBN978-0486236735
- ^Piskunov, A. E.; et al. (January 2008), "Tidal radii and masses of open clusters",Astronomy and Astrophysics,477(1): 165–172,Bibcode:2008A&A...477..165P,doi:10.1051/0004-6361:20078525.
- ^Mermilliod, J. -C.; et al. (October 2007), "Red giants in open clusters. XIII. Orbital elements of 156 spectroscopic binaries",Astronomy and Astrophysics,473(3): 829–845,Bibcode:2007A&A...473..829M,doi:10.1051/0004-6361:20078007.
- ^Cuffey, James (1940). "The Galactic Clusters NGC 6649 and NGC 6694".Astrophysical Journal.92:303.Bibcode:1940ApJ....92..303C.doi:10.1086/144220.
- ^Merrifield, Michael (Oct 2, 2015)."M26 - Open Cluster".Deep Sky Videos.University of Nottingham/University of Sheffield.RetrievedMarch 29,2016.
External links
[edit]
- Messier 26, SEDS Messier pages
- Messier 26 onWikiSky:DSS2,SDSS,GALEX,IRAS,Hydrogen α,X-Ray,Astrophoto,Sky Map,Articles and images
| List |
|  |
|---|---|---|
| See also | ||
