| NGC 877 | |
|---|---|
 | |
| Observation data (J2000epoch) | |
| Constellation | Aries |
| Right ascension | 02h 17m 59.6s[1] |
| Declination | +14° 32′ 38″[1] |
| Redshift | 0.013052 ± 0.000010[1] |
| Heliocentric radial velocity | 3,913 ± 3km/s[1] |
| Distance | 154 ± 25Mly (47.1 ± 7.5Mpc)[1] |
| Apparent magnitude (V) | 11.8[2] |
| Characteristics | |
| Type | SAB(rs)bc[1] |
| Apparent size (V) | 2.4′ × 1.8′[1] |
| Notable features | Luminous infrared galaxy |
| Other designations | |
| UGC 1768, CGCG 438-052,MCG +02-06-058,PGC 8775[1] | |
NGC 877 is anintermediate spiral galaxy located in the constellationAries. It is located at a distance of circa 160 millionlight years from Earth, which, given its apparent dimensions, means that NGC 877 is about 115,000 light years across. It was discovered byWilliam Herschel on October 14, 1784.[3] Itinteracts withNGC 876.
NGC 877 features twospiral arms with agrand design pattern and slightly disturbed morphology. When pictured inH-alpha, the arms have numerous knots and appear brighter than the nucleus.[4] The northwest part of the galaxy has higher polarised emission than the rest of the galaxy. Abar appears in radio waves.[5]The nucleus has activity that resembles that of aHII region.[6] The galaxy has been categorised as aluminous infrared galaxy, a category of galaxies associated with high star formation rate. The totalinfrared luminosity of the galaxy is estimated to be between1011.04 L☉[7] and1011.1 L☉, lying near the threshold to classify a galaxy as luminous infrared. The total star formation rate in NGC 877 is estimated to be between 20 and 53M☉ per year.[8]
One possiblesupernova has been observed in NGC 877, SN 2019rn. It was discovered by the robotic sky survey ATLAS on January 12.30, 2019, using a twin 0.5m telescope system. It hadapparent magnitude 18.9 on discovery.[9] The supernova was initially classified as atype II supernova withspectroscopic observations by Keck-II,[10] and further spectrographic observations categorised it as type IIb, although it could also be acataclysmic variable or another type ofvariable star.[11]
NGC 877 forms a pair with the edge-on spiral galaxyNGC 876, which lies 2.1 arcminutes to the southwest. At the distance of NGC 877, this corresponds to a projected distance of 30 kpc.[4] A low surface brightness bridge connects the two galaxies.[5]NGC 870 andNGC 871 are two other nearby galaxies.[4] NGC 877 is the brightest and most massive member of agalaxy group known as the NGC 877 group or LGG (Lyon Groups of Galaxies) 53. Other members of the group include NGC 876 and NGC 871, as well as UGC 1693, IC 1791, UGC 1773, and UGC 1817.[12] The group contains large amounts ofHI gas.[13]
During theOctober 2050 lunar eclipse, aTotal Lunar Eclipse, it will be occulted by theMoon over the southeastPacific Ocean,South America and theAtlantic Ocean. This will happen again during theOctober 2069 lunar eclipse over the northern half ofAsia and theNorthwest Pacific.[14]: 161
