DDO 190 ( UGC 9240 ) is a dwarf irregular galaxy in the vicinity of the Milky Way , relatively small and without a clear structure. The galaxy is located at a distance of 2.79 Mpc from the Sun and lies outside the Local Group ; the distance was determined by the top of the branch of the red giants . [6] Older and red stars are observed on the periphery of the galaxy, and young blue stars are in the center. In some areas, heated gas is observed. [7] DDO 190 shows signs of star formation. The galaxy is classified as a morphological type of Magellanic dwarf galaxies, a subtype of irregular galaxies. The metallicity is [Fe / H] = −1.55 ± 0.12. [6]
| DDO 190 | |
|---|---|
| Galaxy | |
 | |
| Research history | |
| Discoverer | |
| opening date | |
| Designations | , , , , , , , and |
| Observational data ( Age J2000.0 ) | |
| Constellation | Bootes |
| Right ascension | |
| Declination | |
| Apparent magnitude m V | 13.25 |
| Specifications | |
| Type of | IAm |
| Radial velocity | |
| Redshift | |
| Distance | 2.8 Mpc h −1 0.73 |
| Absolute magnitude (V) | -14.5 [3] |
| Weight | 5⋅10 7 M ☉ |
DDO 190 is a small galaxy, but not extremely: the diameter is about 15,000 light years, which is approximately 1/6 of the size of the Milky Way. Also, the galaxy is located outside the Local Group containing the nearest galaxies (the Andromeda Galaxy is located less than 3 million light-years from the Sun) and is considered part of the galaxy group M94 . However, DDO 190 is far from the rest of its group facilities; The nearest neighbor is another galaxy, DDO 187 , at a distance of about 0.92 Mpc. [7]
History
The galaxy was discovered by Canadian astronomer Sidney van den Berg in 1959 and placed it in the catalog of the David Dunlap Observatory . [7]
Notes
- ↑ NED results for object UGC 09240 (English) . Date of treatment August 18, 2012.
- ↑ Third reference catalog of bright galaxies, version 9, 1991, New York: Springer-Verlag - 1991.
- ↑ The C star population of DDO 190 (English) , S. 473-480.
- ↑ Giovanelli R. , Haynes M. P. A Digital Archive of H i 21 Centimeter Line Spectra of Optically Targeted Galaxies // The Astrophysical Journal : Supplement Series - 2005.- T. 160, no. 1. - S. 149–162. - ISSN 0067-0049 ; 1538-4365 - doi: 10.1086 / 431550
- ↑ 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 Battinelli, P. The C star population of DDO 190 (PDF). ESO (2006). doi : 10.1051 / 0004-6361: 20052829 . - "The HI mass of DDO 190, estimated at 5 × 107 solar masses by Stil & Israel (2002a) is normal for a galaxy of its luminosity.". Date of treatment August 18, 2012. Archived November 10, 2014.
- ↑ 1 2 3 Galactic Island . NASA (August 17, 2012). Date of treatment August 18, 2012. Archived August 17, 2012.