Astronomy:NGC 2997
| NGC 2997 | |
|---|---|
NGC 2997 | |
| Observation data (J2000 epoch) | |
| Constellation | Antlia |
| Right ascension | 09h 45m 38.75379s[1] |
| Declination | −31° 11′ 27.3570″[1] |
| Helio radial velocity | 1,088±2 km/s[2] |
| Distance | 39.8 megalight-years (12.2 Mpc)[3] |
| Group or cluster | NGC 2997 group |
| Apparent magnitude (V) | 10.1[2] |
| Characteristics | |
| Type | SAB(rs)c[4] or Sc(s)I.3[5] |
| Size | 120,000 ly (36.65 kpc) (estimated)[2] |
| Apparent size (V) | 8′.9 × 6′.8[2] |
| Other designations | |
| ESO 434-35, AM 0943-305, NGC 2997[6], MCG-05-23-012, PGC 27978 [2] | |
NGC 2997 is a face-on unbarred spiral galaxy about 40[3] million light-years away in the faint southern constellation of Antlia.[3] It was discovered by German-born astronomer William Herschel on 4 March 1793. J. L. E. Dreyer described it as, "a remarkable object, very faint, very large, very gradually then very suddenly bright middle and 4 arcsec nucleus.[7] This is the brightest galaxy of the NGC 2997 group of galaxies, and was featured on the cover of the first edition of Galactic Dynamics by James Binney and Scott Tremaine.[8]
This is a grand-design galaxy with a symmetrical, two-armed form.[5] The morphological classification of NGC 2997 is SAB(rs)c,[4] indicating a weakly-barred spiral galaxy (SAB) with an incomplete ring around the bar (rs) and loosely-wound spiral arms (c). It is inclined at an angle of 40° to the line of sight from the Earth, with the major axis aligned along a position angle of 110°.[9] The arms host a series of dusty knots that are star-forming regions being generated through gas compression from density waves.[5] At the core, the arms converge to form a circumnuclear ring with symmetrically-placed hot spots containing super star clusters.[4]
Supernovae
Two supernovae have been detected in NGC 2997.
- SN 2003jg (Type Ib/c, mag. 17) was discovered by the Perth Automated Supernova Search using CCD images taken on 24 October 2003.[10][11] The supernova was positioned 11″ east and 6″ north of the galactic nucleus.[12]
- SN 2008eh (type unknown, mag. 15.1) was discovered by Berto Monard (it) on 21 July 2008, reaching maximum magnitude 15.0.[13][14] It was positioned 123″ east and 34″ north of the galactic core.
See also
References
- ↑ 1.0 1.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 "NASA/IPAC Extragalactic Database". Results for NGC 2997. http://nedwww.ipac.caltech.edu/.
- ↑ 3.0 3.1 3.2 Hess, K. M. et al. (2009). "Anomalous HI in NGC 2997". The Astrophysical Journal 699 (1): 76–88. doi:10.1088/0004-637X/699/1/76. Bibcode: 2009ApJ...699...76H.
- ↑ 4.0 4.1 4.2 Elmegreen, Debra Meloy et al. (August 1999). "Near-Infrared Observations of Hot Spots in the Circumnuclear Rings of NGC 2997 and NGC 6951". The Astronomical Journal 118 (2): 777–784. doi:10.1086/300970. Bibcode: 1999AJ....118..777E.
- ↑ 5.0 5.1 5.2 Grosbøl, P.; Dottori, H. (June 2009). "Pattern speed of main spiral arms in NGC 2997. Estimate based on very young stellar complexes". Astronomy and Astrophysics 499 (3): L21–L24. doi:10.1051/0004-6361/200911805. Bibcode: 2009A&A...499L..21G.
- ↑ "NGC 2997". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=NGC+2997.
- ↑ Seligman, Courtney. "NGC Objects: NGC 2950 - 2999". Celestial Atlas. https://cseligman.com/text/atlas/ngc29a.htm#2997.
- ↑ Binney, J.; Tremaine, S.. "Galactic Dynamics". Princeton University Press. http://press.princeton.edu/titles/2537.html.
- ↑ Ho, I. -Ting et al. (October 2018). "Azimuthal variations of gas-phase oxygen abundance in NGC 2997". Astronomy & Astrophysics 618: 13. doi:10.1051/0004-6361/201833262. A64. Bibcode: 2018A&A...618A..64H.
- ↑ Martin, R.; Biggs, J. (October 2003). Green, D. W. E.. ed. "Supernova 2003jg in NGC 2997". International Astronomical Union Circular (8235): 1. Bibcode: 2003IAUC.8235....1M. http://www.cbat.eps.harvard.edu/iauc/08200/08235.html#Item1.
- ↑ "SN 2003jg". IAU. https://www.wis-tns.org/object/2003jg.
- ↑ Kuncarayakti, H. et al. (May 2018). "Constraints on core-collapse supernova progenitors from explosion site integral field spectroscopy". Astronomy & Astrophysics 613: 18. doi:10.1051/0004-6361/201731923. A35. Bibcode: 2018A&A...613A..35K.
- ↑ Monard, L. A. G. (July 2008). Green, D. W. E.. ed. "Supernova 2008eh in NGC 2997". Central Bureau Electronic Telegrams (1445): 1. Bibcode: 2008CBET.1445....1M. http://www.cbat.eps.harvard.edu/cbet/001400/CBET001445.txt.
- ↑ "SN 2008eh". IAU. https://www.wis-tns.org/object/2008eh.
External links
- NASA Astronomy Picture of the Day: Grand Design Spiral Galaxy NGC 2997 (30 October 1996)
- NGC 2997 in Antlia
- NGC 2997 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
Coordinates:
09h 45m 38.8s, −31° 11′ 28″
Template:NGC objects:2001-3000
