| NGC 4340 | |
|---|---|
 NGC 4340 imaged by theHubble Space Telescope | |
| Observation data (J2000epoch) | |
| Constellation | Coma Berenices |
| Right ascension | 12h 23m 35.3s[1] |
| Declination | 16° 43′ 20″[1] |
| Redshift | 0.003112/933 km/s[1] |
| Distance | 56,070,000ly |
| Group orcluster | Virgo Cluster |
| Apparent magnitude (V) | 12.10[1] |
| Characteristics | |
| Type | SB0^+(r)[1] |
| Size | ~ 53,400 ly |
| Apparent size (V) | 3.5 x 2.8[1] |
| Other designations | |
| CGCG 99-36, MCG 3-32-21,PGC 40245,UGC 7467, VCC 654[1] | |
NGC 4340 is adouble-barred lenticular galaxy[2][3] located about 55 millionlight-years away[4] in theconstellation ofComa Berenices.[5] NGC 4340 was discovered by astronomerWilliam Herschel on March 21, 1784.[6] NGC 4340 is a member of theVirgo Cluster.[2][3] NGC 4340 is generally thought to be in a pair with the galaxyNGC 4350.[6][7]
NGC 4340 has a small inner bar embedded in a luminous stellar nuclear ring. Even though the ring is luminous, there are no star-forming regions. Instead, the ring is made of mostly old stars in a gas-poor environment. The color of the ring is the same as the color of the surrounding bulge suggesting that it is probably an old, “fossil” remnant of an earlier episode of star-formation.[2] Crossing the inner ring, there is a larger primary bar withansae at the ends.[3] Careful inspection shows that the two bars are slightly misaligned, which suggests they may be independently rotating.[2] The larger primary bar connects to another ring that surrounds the central regions of the galaxy.[7]
Onesupernova has been observed in NGC 4340: SN 1977A (type unknown, mag. 16.2) was discovered by Piotr Grigor'evich Kulikovsky on 27 January 1977.[8][9]
