NGC 708 | |
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![]() NGC 708 imaged by Pan-STARRS | |
Observation data (J2000 epoch) | |
Constellation | Andromeda |
Right ascension | 01h 52m 46.4467s [1] |
Declination | +36° 09′ 06.581″ [1] |
Redshift | 0.015886 [1] |
Heliocentric radial velocity | 4762 km/s [1] |
Distance | 232.05 ± 16.32 Mly (71.147 ± 5.005 Mpc) [1] |
Group or cluster | Abell 262 |
Apparent magnitude (V) | 13.70 [1] |
Characteristics | |
Type | E [1] |
Size | ~200,000 ly (62 kpc) (estimated) [1] |
Apparent size (V) | 3.0′ × 2.5′ [1] |
Other designations | |
B2 0149+35, HOLM 049A, UGC 1348, MCG +06-05-031, PGC 6962, CGCG 522-039 [1] |
NGC 708 is an elliptical galaxy located 240 million light-years away [1] in the constellation Andromeda. It was discovered by German-British astronomer William Herschel on September 21, 1786. [2] It is classified as a cD galaxy [3] [4] and is the brightest member of Abell 262. [5] [6] NGC 708 is a weak [7] FR I radio galaxy [8] [9] [10] [11] [12] and is also classified as a type 2 Seyfert galaxy. [7] [13] [1]
NGC 708 is surrounded by 4,700 globular clusters. [14]
Discovered in 1979 by Kotanyi et al., NGC 708 has a thin dust lane [15] with an irregular structure. [16] [17] [18] [4] Besides the dust lane, there are also patches of dust that cross the nucleus. [16] [17] [18] These features are oriented nearly perpendicular to the radio emission of the galaxy. [19] [20] [12] [7] [5] The lane appears to be a nearly edge-on dust disk [21] with a length of 16,000 ly (5 kpc ). [22]
The dust lane appears to have formed from a cooling accretion flow of intracluster medium (ICM) onto NGC 708. [22]
NGC 708 has a supermassive black hole with an estimated mass of (2.9×108 M☉) (108.46) M☉. [23] [9]
The supermassive black hole is powering the radio jets and lobes in the galaxy. [9]
NGC 708 contains two radio jets [22] that are mildly bent [22] [24] and extend into ''s'' shaped [7] [11] double radio lobes [9] [10] [12] [11] with a total length of 200,000 ly (60 kpc ). [11]
Chandra observations have shown that the lobes have created a cavity in the intracluster medium of Abell 262. [10]
NGC 708 may be interacting with NGC 705 which lies about 67,000 ly (20.6 kpc ) to the south-west. [20]