NGC 918
Barred spiral galaxy in the constellation Aries
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NGC 918 is a barred spiral galaxy in the constellation Aries, about 67 million light years from the Milky Way. It was discovered by John Herschel on Jan 11, 1831.[4]
Right ascension02h 25m 50.7648s[1]
Declination+18° 29′ 46.987″[1]
| NGC 918 | |
|---|---|
NGC 918 by the Mount Lemmon SkyCenter | |
| Observation data (J2000 epoch) | |
| Constellation | Aries |
| Right ascension | 02h 25m 50.7648s[1] |
| Declination | +18° 29′ 46.987″[1] |
| Redshift | 0.005037[1] |
| Heliocentric radial velocity | 1510 ± 1 km/s[1] |
| Distance | 20.6±1.5 mpc [2] |
| Apparent magnitude (V) | 15.01[3] |
| Apparent magnitude (B) | 16.0[3] |
| Characteristics | |
| Type | SAB(rs)c[1] |
| Size | ~70,500 ly (21.63 kpc) (estimated)[1] |
| Apparent size (V) | 3.5′ × 2.0′[1] |
| Other designations | |
| IRAS 02230+1816, UGC 1888, MCG +03-07-011, PGC 9236, CGCG 462-011[3][1] | |
The brightness class of NGC 918 is III and it has a broad line of neutral hydrogen. NGC 918 is also an active nucleus galaxy (AGN). Moreover, it is a field galaxy which does not belong to a cluster or group and is therefore gravitationally isolated.[5]
Many non-redshift measures give a distance of 19,115 ± 6,160 Mpc (~62,3 million ly),[6] which is within the distances calculated using the value shift.[2]
Supernovae
Two supernovae have been observed in NGC 918:
- SN 2009js (Type II, mag. 17.2) was discovered by Kōichi Itagaki and independently by the Lick Observatory Supernova Search (LOSS) on October 11, 2009.[7][8][9][10][11] This was the first subluminous supernova to be studied in infrared wavelengths.[10]
- SN 2011ek (Type Ia, mag. 16.4) was discovered by Kōichi Itagaki on Aug. 4, 2011.[12][13][14]
