Open cluster

An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud, and are still gravitationally bound to each other. Open clusters are found only in spiral and irregular galaxies, in which active star formation is occurring. They are usually less than a few hundred million years old: they become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic centre, as well as losing cluster members through internal close encounters.

References

• {{note|Michell}} Michell J. (1767), An Inquiry into the probable Parallax, and Magnitude, of the Fixed Stars, from the Quantity of Light which they afford us, and the particular Circumstances of their Situation, Philosophical Transactions, v. 57, p. 234-264
• {{note|Battinelli}} Battinelli P., Capuzzo-Dolcetta R. (1991), Formation and evolutionary properties of the Galactic open cluster system, Monthly Notices of the Royal Astronomical Society, v. 249, p. 76-83
• {{note|Battinelli2}} also see Battinelli P as previous reference.
• {{note|Eggen}} Eggen O. J. (1960), Stellar groups, VII. The structure of the Hyades group, Monthly Notices of the Royal Astronomical Society, v. 120, p.540
• {{note|Subramaniam}} Subramaniam A., Gorti U., Sagar R., Bhatt H. C. (1995), Probable binary open star clusters in the Galaxy, Astronomy and Astrophysics, v.302, p.86
• {{note|Nilakshi}} Nilakshi S.R., Pandey A.K., Mohan V. (2002), A study of spatial structure of galactic open star clusters, Astronomy and Astrophysics, v. 383, p. 153-162
• {{note|Trumpler}} Trumpler R.J. (1930), Preliminary results on the distances, dimensions and space distribution of open star clusters, Lick Observatory bulletin no. 420, Berkeley : University of California Press, p. 154-188
• {{note|Dias}} Dias W.S., Alessi B.S., Moitinho A., Lépine J.R.D. (2002), New catalogue of optically visible open clusters and candidates, Astronomy and Astrophysics, v. 389, p. 871-873
• {{note|Janes}} Janes K.A., Phelps R.L. (1980), The galactic system of old star clusters: The development of the galactic disk, The Astronomical Journal, v. 108, p. 1773-1785
• {{note|van_den_Bergh}} van den Bergh S., McClure R.D. (1980), Galactic distribution of the oldest open clusters, Astronomy & Astrophysics, v.88, p.360
• {{note|Andronov}} Andronov N., Pinsonneault M., Terndrup D. (2003), Formation of Blue Stragglers in Open Clusters, American Astronomical Society Meeting 203
• {{note|Fellhauer}} Fellhauer M., Lin D.N.C., Bolte M., Aarseth S.J., Williams K.A. (2003), The White Dwarf Deficit in Open Clusters: Dynamical Processes, The Astrophysical Journal, v. 595, pp. L53-L56
• {{note|de_La_Fuente}} de La Fuente M.R. (1998), Dynamical Evolution of Open Star Clusters, Publications of the Astronomical Society of the Pacific, v. 110, pp. 1117-1117
• {{note|VandenBerg}} VandenBerg, D.A., Stetson P.B. (2004), On the Old Open Clusters M67 and NGC 188: Convective Core Overshooting, Color-Temperature Relations, Distances, and Ages, Publications of the Astronomical Society of the Pacific, v. 116, pp. 997-1011
• {{note|Brown}} Brown A.G.A. (2001), Open clusters and OB associations: a review, Revista Mexicana de Astronomía y Astrofísica, v. 11, p89-96
• {{note|Hanson}} Hanson R.B. (1975), A study of the motion, membership, and distance of the Hyades cluster, Astronomical Journal, v. 80, p. 379-401
• {{note|Bragaglia}} Bragaglia A., Held E.V., Tosi M. (2005), Radial velocities and membership of stars in the old, distant open cluster Berkeley 29, Astronomy and Astrophysics, v. 429, p. 881-886