NGC 4639 (other designations are UGC 7884 , IRAS12403 + 1331 , MCG 2-32-189 , ZWG 71.8 , ZWG 70.230 , VCC 1943 , PGC 42741 ) is a spiral galaxy with a jumper in the constellation Virgo .
| NGC 4639 | |
|---|---|
| Galaxy | |
 | |
| Research history | |
| Discoverer | William Herschel |
| opening date | April 12, 1784 |
| Designations | NGC 4639 , UGC 7884 , IRAS12403 + 1331 , MCG 2-32-189 , ZWG 71.8 , ZWG 70.230 , VCC 1943 , PGC 42741 |
| Observational data ( Age J2000.0 ) | |
| Constellation | Virgo |
| Right ascension | |
| Declination | |
| Visible dimensions | 2.9 '× 2.0' |
| Apparent magnitude m V | 11,4 |
| Photographic magnitude m B | 12,2 |
| Specifications | |
| Type of | Sbbc |
| Radial velocity | |
| Redshift | +0.003269 ± 0.000053 |
| Distance | 25.1 Mpc |
| Angular position | 123 ° |
| Surface brightness | 13,2 |
This object is one of those listed in the original edition of the New General Catalog .
Content
Features
One of the weakest Seyfert galaxies ; its luminosity is 1-3 orders of magnitude smaller than the luminosity of most Seyfert galaxies [2] . A compact central source (the active core of the galaxy ) emits in the X-ray range 2-10 keV with an intensity of ~ 8.3 · 10 40 erg / s and demonstrates variability with a time scale from months to years; There are also indications of faster variability with a characteristic time of ~ 10 4 s [2] .
In 1990, a type Ia supernova was discovered in the galaxy, which was designated SN 1990N [3] [4] [5] .
See also
- List of Messier objects
- New shared directory
Notes
- ↑ R. Brent Tully, Courtois H. M., Sorce J. G. COSMICFLOWS-3 // Astron. J. / J. G. III - IOP Publishing , 2016 .-- Vol. 152, Iss. 2. - P. 50. - ISSN 0004-6256 ; 1538-3881 - doi: 10.3847 / 0004-6256 / 152/2/50
- ↑ 1 2 L. Ho et al. , 1999.
- ↑ Central Bureau for Astronomical Telegrams. Circular No. 5039. SUPERNOVA 1990N IN NGC 4639. 1990 June 26.
- ↑ A. Sandage et al. 1996.
- ↑ A. Saha et al. , 1997.
Literature
- Allan Sandage, A. Saha, GA Tammann, Lukas Labhardt, N. Panagia, and FD Macchetto. Cepheid Calibration of the Peak Brightness of Type Ia Supernovae: Calibration of SN 1990N in NGC 4639 Averaged with Six Earlier Type Ia Supernova Calibrations to Give H0 Directly // The Astrophysical Journal . - 1996. - DOI : 10.1086 / 309973 .
- A. Saha, Allan Sandage, Lukas Labhardt, GA Tammann, FD Macchetto, and N. Panagia. Cepheid Calibration of the Peak Brightness of Type Ia Supernovae. Viii. SN 1990N in NGC 4639 (Eng.) // The Astrophysical Journal . - 1997. - DOI : 10.1086 / 304507 .
- Luis C. Ho, Andrew Ptak, Yuichi Terashima, Hideyo Kunieda, Peter J. Serlemitsos, Tahir Yaqoob, and Anuradha P. Koratkar. X-Ray Properties of the Weak Seyfert 1 Nucleus in NGC 4639 (Eng.) // The Astrophysical Journal . - 1999. - DOI : 10.1086 / 307898 .
Links
- Information in English and French from the original “ New General Catalog ”
- Information (Eng.) From the Revised New General Catalog
- SIMBAD
- VizieR (English)
- NASA / IPAC Extragalactic Database
- NGC 4639 Publication List