NGC 6557
| Galaxy NGC 6557 |
|
|---|---|
|
|
| AladinLite | |
| Constellation | Octant |
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Position equinox : J2000.0 , epoch : J2000.0 |
|
| Right ascension | 18 h 21 m 24.822 s |
| declination | -76 ° 34 ′ 58.68 ″ |
| Appearance | |
| Morphological type | SA (r) 0 ^ 0 ^ |
| Brightness (visual) | 12.9 mag |
| Brightness (B-band) | 13.9 likes |
| Angular expansion | 1.6 ′ × 1.1 ′ |
| Position angle | 80 ° |
| Surface brightness | 13.4 mag / arcmin² |
| Physical data | |
| Redshift | 0.018356 ± 0.000150 |
| Radial velocity | 5503 ± 45 km / s |
|
Stroke distance v rad / H 0 |
(240 ± 17) x 10 6 ly (73.5 ± 5.2) Mpc |
| history | |
| discovery | John Herschel |
| Discovery date | June 30, 1835 |
| Catalog names | |
| NGC 6557 • PGC 61770 • ESO 045-001 • 2MASX J18212466-7634598 • SGC 181412-7636.3 • GC 4381 • h 3728 • 2MASS J18212481-7635001 • LDCE 1302 NED002 | |
NGC 6557 is a 12.9 likes bright lenticular galaxy of Hubble type S0 in the constellation Oktant the southern sky . It is estimated to be 240 million light years from the Milky Way and about 120,000 light years in diameter.
The object was discovered on June 30, 1835 by John Herschel with an 18-inch reflector telescope, who noted "vF, R, glbM, 15 arcseconds".
Web links
- NGC 6557. SIMBAD , accessed September 15, 2019 .
- NGC 6557. DSO Browser, accessed September 15, 2016 .