NGC 684 is a spiral galaxy approximately 135 million light-years away from Earth in the constellation of Triangulum.[1] It was discovered by William Herschel on October 26, 1786.[3] Edward Swift, Lewis' son, found this galaxy again on 18 Jan 1890 while "searching for Swift's Comet." and it was reported as a new object in list IX-6.[3]
NGC 684 Group
NGC 684 is the largest member of a group of galaxies named after it (also known as LGG 32), which includes the galaxies NGC 670 and IC 1731.[4]
Supernovae
Two supernovae have been observed in NGC 684:
- SN 2021ass (type II, mag. 18.1122) was discovered by the Zwicky Transient Facility on 18 January 2021.[5]
- SN 2025aml (type II, mag. 18.1168) was discovered by the Zwicky Transient Facility on 31 January 2025.[6]
See also
References
- ^ a b c d e f g h i j "Results for object NGC 0684". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 4 December 2017.
- ^ a b "Revised NGC Data for NGC 684". spider.seds.org. Retrieved December 9, 2017.
- ^ a b "Data for NGC 684". www.astronomy-mall.com. Retrieved December 9, 2017.
- ^ Garcia, A. M. (1993). "General study of group membership. II. Determination of nearby groups". Astronomy and Astrophysics Supplement Series. 100: 47. Bibcode:1993A&AS..100...47G.
- ^ "SN 2021ass". Transient Name Server. IAU. Retrieved 4 September 2024.
- ^ "SN 2025aml". Transient Name Server. IAU. Retrieved 31 January 2025.
External links
Media related to NGC 684 at Wikimedia Commons- NGC 684 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- SEDS
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