NGC 4638 is an edge-on lenticular galaxy[2] located about 50 million light-years away[3] in the constellation Virgo.[4] NGC 4638 was discovered by astronomer William Herschel on March 15, 1784.[5] The galaxy is a member of the Virgo Cluster.[6][7]

NGC 4638
Sloan Digital Sky Survey image of NGC 4638.
Observation data (J2000 epoch)
ConstellationVirgo
Right ascension12h 42m 47.4s[1]
Declination11° 26′ 33″[1]
Redshift0.003843[1]
Heliocentric radial velocity1152 km/s[1]
Distance50.77 Mly (15.565 Mpc)[1]
Group or clusterVirgo Cluster
Apparent magnitude (V)12.1[1]
Characteristics
TypeS0[1]
Size~42,800 ly (13.13 kpc) (estimated)[1]
Apparent size (V)2.17 x 1.27[1]
Other designations
NGC 4667, CGCG 70-229, CGCG 71-6, MCG 2-32-187, PGC 42728, UGC 7880, VCC 1938[1]

Structure

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At the center of NGC 4638, there is a small bulge. There is also an edge-on disk and a diffuse, boxy halo. The shallow surface brightness gradient of the halo is characteristic of a large spheroidal galaxy. This means that NGC 4638 has properties of both S0 and Sph galaxies.[8]

See also

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References

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  1. ^ a b c d e f g h i j "NASA/IPAC Extragalactic Database". Results for NGC 4638. Retrieved 2018-03-29.
  2. ^ Falcón-Barroso, Jesús; Knapen, Johan H. (2013-09-02). Secular Evolution of Galaxies. Cambridge University Press. p. 110. ISBN 978-1-107-03527-0.
  3. ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2018-03-31.
  4. ^ "Revised NGC Data for NGC 4638". spider.seds.org. Retrieved 2018-03-31.
  5. ^ "New General Catalog Objects: NGC 4600 - 4649". cseligman.com. Retrieved 2018-03-31.
  6. ^ Binggeli, B.; Sandage, A.; Tammann, G. A. (1985-09-01). "Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area". The Astronomical Journal. 90: 1681–1759. Bibcode:1985AJ.....90.1681B. doi:10.1086/113874. ISSN 0004-6256.
  7. ^ "The Virgo Cluster". www.atlasoftheuniverse.com. Retrieved 2018-03-31.
  8. ^ Kormendy, John; Bender, Ralf (2012). "A Revised Parallel-sequence Morphological Classification of Galaxies: Structure and Formation of S0 and Spheroidal Galaxies". The Astrophysical Journal Supplement Series. 198 (1): 2. arXiv:1110.4384. Bibcode:2012ApJS..198....2K. doi:10.1088/0067-0049/198/1/2. ISSN 0067-0049. S2CID 118326756.
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