| NGC 5557 | |
|---|---|
 SDSS image of NGC 5557 | |
| Observation data (J2000 epoch) | |
| Constellation | Boötes |
| Right ascension | 14 18 25.708 |
| Declination | +36° 29′ 37.28″ |
| Redshift | 0.010764 |
| Heliocentric radial velocity | 3210 ± 28 km/s |
| Distance | 127 Mly (38.8 Mpc) |
| Apparent magnitude (V) | 12.2 |
| Absolute magnitude (V) | −22.39 |
| Characteristics | |
| Type | E1 |
| Other designations | |
| UGC 9161, MCG +06-31-093, PGC 51104 | |
NGC 5557 is an elliptical galaxy in the constellation Boötes. It was discovered by William Herschel on May 1, 1785. The distance to NGC 5557 is not well known, but it is estimated to be about 127 million light-years (38.8 megaparsecs) away.
NGC 5557 is quite massive, with a K-band absolute magnitude of −24.8, and is a slow rotator, which suggests it gained mass through dry mergers (galaxy mergers involving galaxies significant amounts of gas). However, it has a faint tidal tail to its east, as well as a more complex structure to the west. This structure, if found to be connected to NGC 5557, would one of the largest around a galaxy, spanning about 1.1 million light-years (350,000 parsecs). This filamentary structure suggests that NGC 5557 may have formed from a more gas-rich galaxy merger a couple billion years ago. This implies that the galaxy merger would need to have a low impact parameter.
NGC 5557 is part of a galaxy group, and is the largest such galaxy in the group by far. Surrounding the galaxy near the eastern filament are several small bluish objects, which are possibly tidal dwarf galaxies.
Supernovae
Two supernovae have been observed in NGC 5557:
- SN 1996aa (type Ia, mag. 17) was discovered by Wayne Johnson on 16 May 1996.
- SN 2013gn (type Ia, mag. 15.3) was discovered by Kōichi Itagaki on 16 November 2013.
References
- ^ Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi:10.1086/498708. ISSN 0004-6256. S2CID 18913331.
- ^ "NGC 5557". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-04-17.
- ^ Duc, Pierre-Alain; Cuillandre, Jean-Charles; Serra, Paolo; Michel-Dansac, Leo; Ferriere, Etienne; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frédéric; Bureau, Martin; Cappellari, Michele; Davies, Roger L.; Davis, Timothy A.; De Zeeuw, P. T.; Emsellem, Eric; Khochfar, Sadegh; Krajnović, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; McDermid, Richard M.; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Weijmans, Anne-Marie; Young, Lisa M. (2011). "The ATLAS project - IX. The merger origin of a fast- and a slow-rotating early-type galaxy revealed with deep optical imaging: First results". Monthly Notices of the Royal Astronomical Society. 417 (2): 863–881. arXiv:1105.5654. Bibcode:2011MNRAS.417..863D. doi:10.1111/j.1365-2966.2011.19137.x. S2CID 6762647.
- ^ Seligman, Courtney. "New General Catalogue objects: NGC 5550 - 5599". cseligman.com. Retrieved 2021-04-17.
- ^ Bonfini, Paolo (2014). "GALFIT-CORSAIR: Implementing the Core-Sérsic Model into GALFIT". Publications of the Astronomical Society of the Pacific. 126 (944): 935–947. arXiv:1408.6846. Bibcode:2014PASP..126..935B. doi:10.1086/678566. S2CID 119256809.
- Johnson, W.; Garnavich, P.; Riess, A.; Kirshner, R.; Barton, E. (1996). "Supernova 1996aa in NGC 5557". International Astronomical Union Circular (6403): 1. Bibcode:1996IAUC.6403....1J.
- "SN 1996aa". Transient Name Server. IAU. Retrieved 9 December 2024.
- Nakano, S.; Yusa, T.; Ueno, I.; Itoh, R.; Kawabata, K. S.; Yamanaka, M.; Ayani, K.; Yamaoka, H. (2013). "Supernova 2013gn in NGC 5557 = PSN J14182850+3630244". Central Bureau Electronic Telegrams. 3727: 1. Bibcode:2013CBET.3727....1N.
- "SN 2013gn". Transient Name Server. IAU. Retrieved 9 December 2024.
External links
Media related to NGC 5557 at Wikimedia Commons
| Astronomical catalogs | |
|---|---|
| NGC | |
