NGC 4638

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)
Constellation	Virgo
Right ascension	12^h 42^m 47.4^s[1]
Declination	11° 26′ 33″[1]
Redshift	0.003843[1]
Helio radial velocity	1152 km/s[1]
Distance	50.77 Mly (15.565 Mpc)[1]
Group or cluster	Virgo Cluster
Apparent magnitude (V)	12.1[1]
Characteristics
Type	S0[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

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

• List of NGC objects (4001–5000)
• Lenticular galaxy

References

1. "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.

External links

• NGC 4638 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images