NGC 247
Galaxy NGC 247 |
|
---|---|
NGC 247 recorded with the Wide Field Imager at the 2.2 meter telescope of the MPG / ESO in the La Silla Observatory | |
AladinLite | |
Constellation | whale |
Position equinox : J2000.0 , epoch : J2000.0 |
|
Right ascension | 00 h 47 m 08.55 s |
declination | -20 ° 45 ′ 37.4 ″ |
Appearance | |
Morphological type | SAB (s) d / HII |
Brightness (visual) | 8.9 likes |
Brightness (B-band) | 9.6 likes |
Angular expansion | 19.9 ′ × 5.5 ′ |
Position angle | 172 ° |
Inclination | 75 ° |
Surface brightness | 13.8 mag / arcmin² |
Physical data | |
Affiliation | Sculptor group |
Redshift | 0.000520 ± 0.000007 |
Radial velocity | 156 ± 2 km / s |
Stroke distance v rad / H 0 |
(8 ± 1) x 10 6 ly (2.36 ± 0.17) Mpc |
Dimensions | approx. 1.8 · 10 10 M ☉ |
diameter | approx. 50,000 ly |
history | |
discovery | Wilhelm Herschel |
Discovery date | October 20, 1784 |
Catalog names | |
NGC 247 • UGCA 11 • PGC 2758 • ESO 540-022 • MCG -04-03-005 • IRAS 00446-2101 • KUG 0044-210 • 2MASX J00470855-2045374 • GC 132 • H V 20 • h 57 • HIPASS J0047- 20 • LDCE 26 NED005 |
NGC 247 is a faint bar spiral galaxy of the Hubble type SBcd with extensive star formation areas in the constellation Whale south of the ecliptic . It is estimated to be 8 million light years from the Milky Way and about 50,000 light years in diameter . The galaxy belongs to the Sculptor group that is adjacent to our local group .
One difficulty in determining the range of NGC 247 is that from Earth we see the galaxy from the side. The distance of galaxies is determined by the apparent brightness of variable stars, the Cepheids . The side view weakens the light from interstellar dust and the stars appear to be further away. Measurements of the Araucaria project in the infrared range from 2009 showed that the extinction had been somewhat underestimated in previous studies and led to a distance estimate that was 7% lower.
The object was discovered on October 20, 1784 by the German-British astronomer Wilhelm Herschel .
Ultraviolet image of NGC 247 by GALEX .
Detail of the center using the Hubble Space Telescope
Web links
- SIMBAD Astronomical Database
- ESO : VISTA's view of the Sculptor Galaxy (+ photos & animation) June 16, 2010
- ESO: The Dusty Disk of NGC 247 (+ photos, map & animation) March 2nd, 2011
- Aladin Lite
- Image: wikisky.org. WikiSky, accessed March 6, 2011 (taken from GALEX).
- Image: NGC 247 in Cetus. AstroSurf, November 4, 2002, accessed on March 6, 2011 (taken in Antilhue - Chile).
- astronews.com: Picture of the day October 5, 2016
- Spektrum.de : Amateur recordings [1] [2]