NGC 4638 explained

NGC 4638
Epoch:	J2000
Type:	S0^[1]
Dist Ly:	15.565Mpc
Group Cluster:	Virgo Cluster
H Radial V:	1152 km/s
Z:	0.003843
Appmag V:	12.1
Size V:	2.17 x 1.27
Constellation Name:	Virgo
Names:	NGC 4667, CGCG 70-229, CGCG 71-6, MCG 2-32-187, PGC 42728, UGC 7880, VCC 1938
Size:	~13.13kpc (estimated)

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]}

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)

Notes and References

1. Web site: NASA/IPAC Extragalactic Database . Results for NGC 4638 . 2018-03-29.
2. Book: Secular Evolution of Galaxies. Falcón-Barroso. Jesús. Knapen. Johan H.. 2013-09-02. Cambridge University Press. 978-1-107-03527-0. 110.
3. Web site: Your NED Search Results. ned.ipac.caltech.edu. 2018-03-31.
4. Web site: Revised NGC Data for NGC 4638. spider.seds.org. 2018-03-31.
5. Web site: New General Catalog Objects: NGC 4600 - 4649. cseligman.com. en-US. 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.. 1985AJ.....90.1681B. The Astronomical Journal. 90. 1681–1759. 10.1086/113874. 0004-6256.
7. Web site: The Virgo Cluster. www.atlasoftheuniverse.com. 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. en. 198. 1. 2. 10.1088/0067-0049/198/1/2. 0067-0049. 1110.4384. 2012ApJS..198....2K. 118326756.