| NGC 1637 | |
|---|---|
 Very Large Telescope image of NGC 1637. | |
| Observation data (J2000 epoch) | |
| Constellation | Eridanus |
| Right ascension | 04 41 28.229 |
| Declination | −02° 51′ 28.94″ |
| Redshift | 0.00239 |
| Heliocentric radial velocity | 717.1±1.2 km/s |
| Distance | 9.77 ± 1.82 Mpc (31.9 ± 5.9 Mly) 9.18 Mpc (29.9 Mly) h 0.73 |
| Apparent magnitude (V) | 11.5 |
| Apparent magnitude (B) | 11.25 |
| Characteristics | |
| Type | SAB(rs)c or SBc(s)II.3 |
| Size | ~57,000 ly (17.48 kpc) (estimated) |
| Apparent size (V) | 4.0′ × 3.2′ |
| Other designations | |
| AGC 440323, IRAS 04389-0257, UGCA 93, MCG +00-12-068, PGC 15821, CGCG 393-066 | |
NGC 1637 is an isolated, non-interacting intermediate spiral galaxy in the constellation Eridanus, about a degree to the WNW of the star Mu Eridani. It was discovered by German-British astronomer William Herschel on 1 February 1786. It is located at a distance of about 9.77 ± 1.82 Mpc (31.9 ± 5.9 Mly) from the Milky Way. The galaxy is inclined at an angle of 31.1° to the line of sight from the Earth and the long axis is oriented along a position angle of 16.3°.
In 1991, Gérard de Vaucouleurs and associates assigned a morphological classification of SAB(rs)c to NGC 1637, indicating a spiral galaxy with a weak bar structure (SAB) across the nucleus, surrounded by a partial ring (rs) and somewhat loosely-wound arms (c). While the inner section of the galaxy shows a symmetrical two-arm structure, it has a single outer spiral arm that wraps 180° around the nucleus, giving the galaxy an overall asymmetric, lopsided appearance. The outer spiral arm has a red component that indicates a significant age. However, the existence of this structure is difficult to explain. The galaxy shows indications of recent starburst activity that may have terminated around 15 million years ago.
The active central nucleus shows weak LINER behavior, and it may be an intermediate form between a LINER and an H II region. The luminosity of the X-ray source at the nucleus is 1.2×10 ergs s in the 0.3–7 keV band.
Supernova
One supernova has been observed in NGC 1637. SN 1999em (type II-P, mag. 13.5) was discovered by the Lick Observatory Supernova Search (LOSS) on 29 October 1999, at an angular separation of 24″ to the southwest of the galaxy center. It was the brightest supernova discovered that year, reaching magnitude 13.1. The location corresponds to a deprojected galactocentric separation of 1.3 kpc (4.2 kly).
Image and Video Gallery
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NGC 1637 imaged by the Hubble Space Telescope
- Video showing the location of NGC 1637
See also
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.
- ^ Haynes, Martha P.; et al. (January 1998). "Asymmetry in High-Precision Global H i Profiles of Isolated Spiral Galaxies". The Astronomical Journal. 115 (1): 62–79. Bibcode:1998AJ....115...62H. doi:10.1086/300166. S2CID 123380349.
- ^ Crowther, Paul A. (January 2013). "On the association between core-collapse supernovae and H ii regions". Monthly Notices of the Royal Astronomical Society. 428 (3): 1927–1943. arXiv:1210.1126. Bibcode:2013MNRAS.428.1927C. doi:10.1093/mnras/sts145.
- "NASA/IPAC Extragalactic Database". Results for NGC 1512, Co-Moving Radial Distance. Retrieved 2014-12-18.
- ^ "NASA/IPAC Extragalactic Database". Results for NGC 1637. Retrieved 2006-11-25.
- ^ Immler, Stefan; et al. (October 2003). "A Deep Chandra X-Ray Observation of NGC 1637". The Astrophysical Journal. 595 (2): 727–742. Bibcode:2003ApJ...595..727I. doi:10.1086/377474.
- ^ Sohn, Young-Jong; Davidge, T. J. (January 1998). "VRI CCD Photometry of Supergiant Stars in the Barred Galaxies NGC 925 and NGC 1637". The Astronomical Journal. 115 (1): 130–143. Bibcode:1998AJ....115..130S. doi:10.1086/300163.
- Sinnott, Roger W.; Perryman, Michael A. C. (1997). Millennium Star Atlas. Vol. 1. Sky Publishing Corporation and the European Space Agency. ISBN 0-933346-84-0.
- Seligman, Courtney. "New General Catalogue Objects: NGC 1637". Celestial Atlas. Retrieved 30 November 2024.
- Li, W. D. (1999). "Supernova 1999em in NGC 1637". International Astronomical Union Circular (7294): 1. Bibcode:1999IAUC.7294....1L.
- "SN 1999em". Transient Name Server. IAU. Retrieved 30 November 2024.
- Bishop, David. "Bright Supernovae - 1999 : SN 1999em". Astronomy Section, Rochdale Academy of Science. Retrieved 2024-11-30.
External links
Media related to NGC 1637 at Wikimedia Commons
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