Galaxy in the constellation Virgo
NGC 4639 is abarred spiral galaxy located in theequatorial constellation ofVirgo . It was discovered by German-born astronomerWilliam Herschel on 12 April 1784.John L. E. Dreyer described it as "pretty bright, small, extended, mottled but not resolved, 12th magnitude star 1 arcmin to southeast".[ 7] [ 8] light-years away from theMilky Way .[ 3] NGC 4654 , and the two appear to haveinteracted roughly 500 million years ago.[ 9] 4639 is a member of theVirgo Cluster .[ 10]
Themorphological classification of this galaxy is SAB(rs)bc,[ 5] spiral arms (bc). NGC 4639 has a mildlyactive galactic nucleus of theSeyfert type 1 ; one of the weakest known. The compact central source has been detected by itsX-ray emission , and is variable on timescales of months to years.[ 8] supermassive black hole at the core[ 11] × 106 M ☉ [ 12]
Twosupernovae have been observed in NGC 4639:
SN 1990N (type Ia , mag. 15.5) was discovered by E. Thouvenot on 22 June 1990, two weeks before reaching peak brightness.[ 13] [ 14] [ 15] ″ [ 13] standard candle .[ 15] SN 2018imf (type IIP , mag. 15.8) was discovered byKōichi Itagaki on 14 November 2018.[ 16] VCC 1931 .] ^ "Elegant spiral hides a hungry monster" .Hubble Space Telescope . ESA. Retrieved13 October 2015 .^a b Brown, A. G. A. ; et al. (Gaia collaboration) (August 2018)."Gaia Data Release 2: Summary of the contents and survey properties" .Astronomy & Astrophysics 616 . A1.arXiv :1804.09365 Bibcode :2018A&A...616A...1G doi :10.1051/0004-6361/201833051 Gaia DR2 record for this source atVizieR .^a b c Tully, R. Brent; et al. (October 2013), "Cosmicflows-2: The Data",The Astronomical Journal ,146 (4): 25,arXiv :1307.7213 Bibcode :2013AJ....146...86T ,doi :10.1088/0004-6256/146/4/86 ,S2CID 118494842 , 86 ^a b c "NASA/IPAC Extragalactic Database" .Results for NGC 4639 . Retrieved2007-04-01 .^a b Graham, Alister W.; et al. (March 2019)."Expected intermediate-mass black holes in the Virgo cluster - II. Late-type galaxies" .Monthly Notices of the Royal Astronomical Society .484 (1):814– 831.arXiv :1811.03232 Bibcode :2019MNRAS.484..814G .doi :10.1093/mnras/sty3068 S2CID 119303249 . ^ "NGC 4639" .SIMBAD Centre de données astronomiques de Strasbourg . Retrieved2020-09-21 .^ Seligman, Courtney."New General Catalogue objects: NGC 4600 - 4649" .cseligman.com . Retrieved2020-09-19 . ^a b Ho, Luis C.; et al. (November 1999). "X-Ray Properties of the Weak Seyfert 1 Nucleus in NGC 4639".The Astrophysical Journal .525 (1):168– 175.arXiv :astro-ph/9905013 Bibcode :1999ApJ...525..168H .doi :10.1086/307898 .S2CID 14517224 . ^ Vollmer, B. (February 2003). "NGC 4654: Gravitational interaction or ram pressure stripping?".Astronomy and Astrophysics .398 (2):525– 539.arXiv :astro-ph/0211321 Bibcode :2003A&A...398..525V .doi :10.1051/0004-6361:20021729 .S2CID 7265130 . ^ "Detailed Object Classifications" .ned.ipac.caltech.edu . Retrieved2017-08-29 .^ Botkin-Kowacki, Eva (13 October 2015)."Spectacular Hubble photo: A bright galaxy holds a hidden secret" .The Christian Science Monitor . Retrieved14 October 2015 . ^ Chiaraluce, E.; et al. (May 2019)."From radio-quiet to radio-silent: low-luminosity Seyfert radio cores" .Monthly Notices of the Royal Astronomical Society .485 (3):3185– 3202.arXiv :1902.10670 Bibcode :2019MNRAS.485.3185C .doi :10.1093/mnras/stz595 S2CID 119089306 . ^a b Maury, A.; et al. (June 1990). Green, D. W. E. (ed.). "Supernova 1990N in NGC 4639".IAU Circular .5039 : 1.Bibcode :1990IAUC.5039....1M . ^ "SN 1990N" .Transient Name Server .IAU . Retrieved6 December 2024 .^a b Saha, A.; et al. (September 1997). "Cepheid Calibration of the Peak Brightness of Type Ia Supernovae. VIII. SN 1990N in NGC 4639".The Astrophysical Journal .486 (1):1– 20.Bibcode :1997ApJ...486....1S .doi :10.1086/304507 . ^ "SN 2018imf" .Transient Name Server .IAU . Retrieved6 December 2024 .NGC 4639 at Wikimedia Commons
Media related toNGC 4639 at Wikimedia Commons
