NGC 663 (also known as Caldwell 10) is a young open cluster in the constellation of Cassiopeia. It has an estimated 400 stars and spans about a quarter of a degree across the sky. It can reportedly be detected with the unaided eye, although a telescope is recommended for best viewing. The brightest members of the cluster can be viewed with binoculars. Although the listed visual magnitude is 7.1, several observers have reported higher estimates.[1]
After adjusting for reddening due to interstellar dust, the distance modulus is estimated as 11.6 magnitudes. It is located about 2,100 parsecs distant with an estimated age of 20–25 million years.[2] This means that stars of spectral class B2 or higher (in the sense of higher mass), are reaching the end of their main sequence lifespan.[3] This cluster appears to be located in front of a molecular cloud, although the two are not physically associated. This cloud has the effect of blocking background stars from the visual image of the cluster as it lies at a distance of 300 parsecs.[4]
This cluster is of interest because of the high number of Be stars, with a total of about 24 discovered. These are spectral class B stars that show prominent emission lines of hydrogen in their spectrum. Most of the Be stars in the cluster lie between spectral class B0 and B3.[2] A candidate member of the cluster, LS I +61° 235, is a Be star with an X-ray binary component that has a period of about three years.[5] There are at least five blue stragglers in the cluster. These are stars that formed by the merger of two other stars.[3] Two of the cluster's star systems are likely eclipsing binaries with periods of 0.6 and 1.03 days.[6] NGC 663 also has two red supergiant stars, both located on its periphery[7][8]
^ ab Pigulski, A.; Kopacki, G.; Kolaczkowski, Z. (2001). "The young open cluster NGC 663 and its Be stars". Astronomy & Astrophysics. 376 (1): 144–153. Bibcode:2001A&A...376..144P. doi:10.1051/0004-6361:20010974.
^ ab Marco, A.; Negueruela, I.; Motch, C. (2007). "Blue Stragglers, Be Stars and X-ray Binaries in Open Clusters". ASP Conference Series. 361: 388. Bibcode:2007ASPC..361..388M.
^ Phelps, Randy L.; Janes, Kenneth A. (1993). "Young open clusters as probes of the star-formation process. 2: Mass and luminosity functions of young open clusters". Astronomical Journal. 106 (5): 1870–1884. Bibcode:1993AJ....106.1870P. doi:10.1086/116772.
^Reig, P.; Fabregat, J.; Coe, M. J.; Roche, P.; et al. (1997). (PDF). Astronomy and Astrophysics. 322 (1): 183–192. Bibcode:1997A&A...322..183R. Archived from the original (PDF) on 2016-03-04. Retrieved 2012-04-17.
^ Pietrzynski, G. (1996). "Variable Stars in the Young Open Cluster NGC 663". Acta Astronomica. 46: 357–360. Bibcode:1996AcA....46..357P.
^Mermilliod, J. C.; Mayor, M.; Udry, S. (2008). "Red giants in open clusters. XIV. Mean radial velocities for 1309 stars and 166 open clusters". Astronomy & Astrophysics. 485 (1): 303–314. Bibcode:2008A&A...485..303M. CiteSeerX10.1.1.30.7545. doi:10.1051/0004-6361:200809664.
^Pandey, A. K.; Upadhyay, K.; Ogura, K.; Sagar, Ram; et al. (2005). "Stellar contents of two young open clusters: NGC 663 and 654". Monthly Notices of the Royal Astronomical Society. 358 (4): 1290–1308. Bibcode:2005MNRAS.358.1290P. doi:10.1111/j.1365-2966.2005.08784.x.
^Negueruela, I.; González-Fernández, C.; Marco, A.; Clark, J. S. (2011). "A massive association around the obscured open cluster RSGC3". Astronomy & Astrophysics. 528: A59. arXiv:1102.0028. Bibcode:2011A&A...528A..59N. doi:10.1051/0004-6361/201016102. S2CID 53517711.
^Humphreys, R. M. (1978). "Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way". Astrophysical Journal Supplement Series. 38: 309–350. Bibcode:1978ApJS...38..309H. doi:10.1086/190559.
External links
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NGC 663 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
April 30, 2023
also, known, caldwell, young, open, cluster, constellation, cassiopeia, estimated, stars, spans, about, quarter, degree, across, reportedly, detected, with, unaided, although, telescope, recommended, best, viewing, brightest, members, cluster, viewed, with, bi. NGC 663 also known as Caldwell 10 is a young open cluster in the constellation of Cassiopeia It has an estimated 400 stars and spans about a quarter of a degree across the sky It can reportedly be detected with the unaided eye although a telescope is recommended for best viewing The brightest members of the cluster can be viewed with binoculars Although the listed visual magnitude is 7 1 several observers have reported higher estimates 1 NGC 663NGC 663 in CassiopeiaObservation data J2000 epoch Right ascension01h 46 0mDeclination 61 15 Distance6 850 ly 2 100 pc Apparent magnitude V 7 1Apparent dimensions V 16 0 Physical characteristicsOther designationsCaldwell 10 Cr 20AssociationsConstellationCassiopeiaSee also Open cluster List of open clustersAfter adjusting for reddening due to interstellar dust the distance modulus is estimated as 11 6 magnitudes It is located about 2 100 parsecs distant with an estimated age of 20 25 million years 2 This means that stars of spectral class B2 or higher in the sense of higher mass are reaching the end of their main sequence lifespan 3 This cluster appears to be located in front of a molecular cloud although the two are not physically associated This cloud has the effect of blocking background stars from the visual image of the cluster as it lies at a distance of 300 parsecs 4 This cluster is of interest because of the high number of Be stars with a total of about 24 discovered These are spectral class B stars that show prominent emission lines of hydrogen in their spectrum Most of the Be stars in the cluster lie between spectral class B0 and B3 2 A candidate member of the cluster LS I 61 235 is a Be star with an X ray binary component that has a period of about three years 5 There are at least five blue stragglers in the cluster These are stars that formed by the merger of two other stars 3 Two of the cluster s star systems are likely eclipsing binaries with periods of 0 6 and 1 03 days 6 NGC 663 also has two red supergiant stars both located on its periphery 7 8 The star cluster is assumed to form part of the stellar association Cassiopeia OB8 that is located in the Perseus arm of the Milky Way along with the open clusters M103 NGC 654 NGC 659 and some supergiant stars scattered between them all of them having similar ages and distances 9 10 Image gallery Edit NGC663 LRGB Using PlaneWave CDK 12 5 from Talent ORReferences Edit O Meara S J 2002 The Caldwell objects Deep sky companions Cambridge University Press pp 50 51 ISBN 978 0 521 82796 6 a b Pigulski A Kopacki G Kolaczkowski Z 2001 The young open cluster NGC 663 and its Be stars Astronomy amp Astrophysics 376 1 144 153 Bibcode 2001A amp A 376 144P doi 10 1051 0004 6361 20010974 a b Marco A Negueruela I Motch C 2007 Blue Stragglers Be Stars and X ray Binaries in Open Clusters ASP Conference Series 361 388 Bibcode 2007ASPC 361 388M Phelps Randy L Janes Kenneth A 1993 Young open clusters as probes of the star formation process 2 Mass and luminosity functions of young open clusters Astronomical Journal 106 5 1870 1884 Bibcode 1993AJ 106 1870P doi 10 1086 116772 Reig P Fabregat J Coe M J Roche P et al 1997 The Be X ray binary LS I 61 235 RX J0146 9 6121 physical parameters and V R variability PDF Astronomy and Astrophysics 322 1 183 192 Bibcode 1997A amp A 322 183R Archived from the original PDF on 2016 03 04 Retrieved 2012 04 17 Pietrzynski G 1996 Variable Stars in the Young Open Cluster NGC 663 Acta Astronomica 46 357 360 Bibcode 1996AcA 46 357P Mermilliod J C Mayor M Udry S 2008 Red giants in open clusters XIV Mean radial velocities for 1309 stars and 166 open clusters Astronomy amp Astrophysics 485 1 303 314 Bibcode 2008A amp A 485 303M CiteSeerX 10 1 1 30 7545 doi 10 1051 0004 6361 200809664 Pandey A K Upadhyay K Ogura K Sagar Ram et al 2005 Stellar contents of two young open clusters NGC 663 and 654 Monthly Notices of the Royal Astronomical Society 358 4 1290 1308 Bibcode 2005MNRAS 358 1290P doi 10 1111 j 1365 2966 2005 08784 x Negueruela I Gonzalez Fernandez C Marco A Clark J S 2011 A massive association around the obscured open cluster RSGC3 Astronomy amp Astrophysics 528 A59 arXiv 1102 0028 Bibcode 2011A amp A 528A 59N doi 10 1051 0004 6361 201016102 S2CID 53517711 Humphreys R M 1978 Studies of luminous stars in nearby galaxies I Supergiants and O stars in the Milky Way Astrophysical Journal Supplement Series 38 309 350 Bibcode 1978ApJS 38 309H doi 10 1086 190559 External links Edit Wikimedia Commons has media related to NGC 663 NGC 663 on WikiSky DSS2 SDSS GALEX IRAS Hydrogen a X Ray Astrophoto Sky Map Articles and images Retrieved from https en wikipedia org w index php title NGC 663 amp oldid 1141285944, wikipedia, wiki, book, books, library,
