SN 1917A is a supernova event in the Fireworks Galaxy (NGC 6946),[2] positioned 37″ west and 105″ south of the galactic core.[1] Discovered by American optician George Willis Ritchey on 19 July 1917, it reached a peak visual magnitude of 13.6.[1] Based on a poor quality[5] photographic spectrum taken at least a month after peak light by F. G. Pease and Ritchey, it was identified as a type II core-collapse supernova.[6][7]
| Event type | Supernova |
|---|---|
| Type II[1] | |
| Date | 19 July 1917[2] |
| Instrument | G. W. Ritchey[1] |
| Constellation | Cepheus[2] |
| Right ascension | 20h 34m 46.9s[1] |
| Declination | +60° 07′ 29″[1] |
| Distance | 22 Mly (6.8 Mpc)[3] |
| Host | NGC 6946[1] |
| Peak apparent magnitude | 13.60[1] |
| Preceded by | SN 1916A[4] |
| Followed by | SN 1919A[4] |
A 2018 analysis of the surrounding stellar population by B. F. Williams suggests the progenitor star was most likely 13+13
−1 million years old with 15+1
−5 times the mass of the Sun (M☉).[3] B. Koplitz and associates in 2021 inferred a progenitor mass estimate of 9.3+16.7
−0.7 M☉.[8] A 2020 search for light echoes from the supernova was unsuccessful.[9]
References edit
- ^ a b c d e f g h Barbon, R.; et al. (2008), "Asiago Supernova Catalogue", CDS/ADC Collection of Electronic Catalogues, Bibcode:2008yCat....1.2024B.
- ^ a b c Frommert, Hartmut; Kronberg, Christine (9 March 2009), "NGC 6946", SEDS, retrieved 2021-12-02.
- ^ a b Williams, Benjamin F.; et al. (June 2018), "Constraints for the Progenitor Masses of Historic Core-collapse Supernovae", The Astrophysical Journal, 860 (1): 10, arXiv:1803.08112, Bibcode:2018ApJ...860...39W, doi:10.3847/1538-4357/aaba7d, S2CID 250890969, 39.
- ^ a b "List of Supernovae", Central Bureau for Astronomical Telegrams, International Astronomical Union, retrieved 2021-12-02.
- ^ Baade, W. (October 1938), "The Absolute Photographic Magnitude of Supernovae", Astrophysical Journal, 88: 285, Bibcode:1938ApJ....88..285B, doi:10.1086/143983.
- ^ Fesen, Robert A.; Weil, Kathryn E. (February 2020), "Detection of Late-time Optical Emission from SN 1941C in NGC 4136", The Astrophysical Journal, 890 (1): 6, arXiv:1910.07723, Bibcode:2020ApJ...890...15F, doi:10.3847/1538-4357/ab67b7, S2CID 204743687, 15.
- ^ Schlegel, E. M. (November 1994), "X-Ray Emission From the Historical Supernovae in the Spiral Galaxy NGC 6946: SN 1980K and 1968D Recovered", Astronomical Journal, 108: 1893, Bibcode:1994AJ....108.1893S, doi:10.1086/117202.
- ^ Koplitz, Brad; et al. (July 2021), "The Masses of Supernova Remnant Progenitors in NGC 6946", The Astrophysical Journal, 916 (1): 18, arXiv:2104.11118, Bibcode:2021ApJ...916...58K, doi:10.3847/1538-4357/abfb7b, S2CID 233347129, 58.
- ^ Radica, M. C.; et al. (September 2020), "A search for supernova light echoes in NGC 6946 with SITELLE", Monthly Notices of the Royal Astronomical Society, 497 (3): 3297–3305, arXiv:2007.02778, Bibcode:2020MNRAS.497.3297R, doi:10.1093/mnras/staa2006.
 | This variable star–related article is a stub. You can help Wikipedia by expanding it. |