NGC 991 explained

NGC 991
Epoch:	J2000
Constellation Name:	Cetus
Z:	0.005126
H Radial V:	1532.8 km/s
Dist Ly:	^[1]
Type:	SAB(rs)c
Appmag B:	12.36
Names:	^[2]

NGC 991 is an intermediate spiral galaxy the constellation Cetus. This galaxy was discovered by astronomer William Herschel in 1785.^{[3] [4] [5]}

A type Ib supernova designated SN 1984L was discovered in this galaxy in late August 1984 by R. Evans.^[6] SN 1984L (type II, mag. 13.5),^[7]

Notes and References

1. Web site: Results for object NGC 0991 (NGC 991). NASA/IPAC Extragalactic Database. California Institute of Technology. 2020-06-03.
2. NGC 991. 2020-06-03.
3. Web site: Your NED Search Results. ned.ipac.caltech.edu. 2020-03-24.
4. Web site: Revised NGC Data for NGC 991. spider.seds.org. 2020-03-24.
5. Web site: The galaxy NGC 991 - In-The-Sky.org. Ford. Dominic. in-the-sky.org. en. 2020-03-24.
6. The peculiar type I supernova in NGC 991 . Wheeler . J. C. . Levreault . R. . Astrophysical Journal . 294. L17–L20 . July 1985 . 10.1086/184500 . 1985ApJ...294L..17W .
7. https://www.wis-tns.org/object/1984L Transient Name Server entry for SN 1984L.