| NGC 3198 | |
|---|---|
 NGC 3198 imaged by the Nicholas U. Mayall Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Ursa Major |
| Right ascension | 10h 19m 55.0022s[1] |
| Declination | +45° 32′ 59.337″[1] |
| Redshift | 0.00227[2] |
| Distance | 47 Mly[3] |
| Apparent magnitude (V) | 10.3[4] |
| Characteristics | |
| Type | SB(rs)c[4] |
| Size | ~121,800 ly (37.33 kpc) (estimated)[1] |
| Apparent size (V) | 8.5′ × 3.3′[4] |
| Other designations | |
| IRAS 10168+4548, UGC 5572, MCG +08-19-020, PGC 30197, CGCG 240-030[2] | |
NGC 3198, also known as Herschel 146[5] is a barred spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on 15 January 1788.[6][3] NGC 3198 is located in the Leo Spur,[3] which is part of the Virgo Supercluster,[7] and is approximately 47 million light years away.[3]
NGC 3198 was one of 18 galaxies targeted by the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale, which aimed to calibrate various secondary distance indicators and determine the Hubble constant to an accuracy of 10%. The type and orientation of NGC 3198 made it suitable for these measurements.[8] The Wide Field and Planetary Camera 2 (WFPC2) of the HST was used to measure the magnitudes of 52 Cepheid variables, and the resulting distance modulus corresponded to a distance of 14.5 Mpc (47 million light years).[8]
Observations made with the Westerbork Synthesis Radio Telescope detected for the first time the presence of extraplanar gas.[9] The extraplanar gas makes up approximately 15% of the total atomic hydrogen (HI) mass of the galaxy.[9]
Supernovae
Two supernovae have been observed in NGC 3198:
- SN 1966J (Type Ia, mag. 13)[10] was discovered by Paul Wild on 18 December 1966.[11] Some sources list this supernova as a Type Ib.[3]
- SN 1999bw (type gap, mag. 17.8) was discovered by the Lick Observatory Supernova Search (LOSS) on 20 April 1999.[12] Significantly fainter than expected when discovered, it was initially classified as a Type IIn supernova.[13][14] In 2021, researchers reclassified it as a gap transient.[15][16]
Gallery
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NGC 3198 imaged by the Sloan Digital Sky Survey -
NGC 3198 imaged by the Spitzer Space Telescope -
NGC 3198 imaged by the Hubble Space Telescope -
NGC 3198 imaged by GALEX (ultraviolet)
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See also
References
- ^ a b c "Results for object NGC 3198". NASA/IPAC Extragalactic Database. NASA and Caltech. Retrieved 14 December 2024.
- ^ a b "NGC 3198". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 July 2015.
- ^ a b c d e O'Meara, Stephen James (2011). Deep-Sky Companions: The Secret Deep, Volume 4. Photographs by Mario Motta. Cambridge University Press. pp. 186–188. ISBN 978-1-139-50007-4.
- ^ a b c Bratton, Mark (2011). The Complete Guide to the Herschel Objects. Cambridge University Press. p. 440. ISBN 978-0-521-76892-4.
- ^ Clark, Maurice. "Herschel 146 / NGC 3198". Herschel 400 List Objects. Retrieved 2017-01-25.
- ^ Seligman, Courtney. "New General Catalogue Objects: NGC 3198". Celestial Atlas. Retrieved 31 August 2024.
- ^ Monks, Neale (2010). Go-To Telescopes Under Suburban Skies. Springer. p. 53. ISBN 978-1-4419-6851-7.
- ^ a b Kelson, Daniel (1999). "The Hubble Space Telescope Key Project on the Extragalactic Distance Scale. XIX. The Discovery of Cepheids in and a New Distance to NGC 3198". The Astrophysical Journal. 514 (2): 614–636. Bibcode:1999ApJ...514..614K. doi:10.1086/306989.
- ^ a b Gentile, G. (2013). "HALOGAS: Extraplanar gas in NGC 3198". Astronomy & Astrophysics. 554: A125. arXiv:1304.4232. Bibcode:2013A&A...554A.125G. doi:10.1051/0004-6361/201321116. S2CID 56047203.
- ^ "SN 1966J". Transient Name Server. IAU. Retrieved 31 August 2024.
- ^ Gingerich, Owen (22 December 1966). "Circular No. 1986". Central Bureau for Astronomical Telegrams. Smithsonian Astrophysical Observatory. Retrieved 2 December 2024.
- ^ Li, W. D. (1999). "Possible Supernova in NGC 3198". International Astronomical Union Circular (7149): 1. Bibcode:1999IAUC.7149....1L.
- ^ Filippenko, A. V.; Li, W. D.; Modjaz, M. (1999). "Supernova 1999bw in NGC 3198". International Astronomical Union Circular (7152): 2. Bibcode:1999IAUC.7152....2F.
- ^ Bishop, David. "Supernova 1999bw in NGC 3198". Astronomy Section Rochester Academy of Science. Retrieved 25 January 2017.
- ^ Ransome, C. L.; Habergham-Mawson, S. M.; Darnley, M. J.; James, P. A.; Filippenko, A. V.; Schlegel, E. M. (2021). "A systematic reclassification of Type IIn supernovae". Monthly Notices of the Royal Astronomical Society. 506 (4): 4715–4734. arXiv:2107.02179. doi:10.1093/mnras/stab1938.
- ^ "AT 1999bw". Transient Name Server. IAU. Retrieved 31 August 2024.
External links
Media related to NGC 3198 at Wikimedia Commons
