NGC 5195
| NGC 5195 | |
|---|---|
A Hubble Space Telescope (HST) image of Messier 51. M51A (the Whirlpool Galaxy) is the spiral galaxy on the left. NGC 5195 is the galaxy in the top right corner.
Credit: HST/STScI/AURA/NASA/ESA. |
|
| Observation data (J2000 epoch) | |
| Constellation | Canes Venatici |
| Right ascension | 13h 29m 59.6s |
| Declination | +47° 15′ 58″ |
| Redshift | 465 ± 10 km/s |
| Distance | 25 ± 3 Mly (7.7 ± 1.0 Mpc) |
| Apparent magnitude (V) | 10.5 |
| Characteristics | |
| Type | Amorphous or SB0 pec |
| Apparent size (V) | 5′.8 × 4′.6 |
| Other designations | |
| Messier 51b,UGC 8494,PGC 47413,Arp 85 | |
NGC 5195 (also known as Messier 51b or M51b) is a dwarf galaxy that is interacting with the Whirlpool Galaxy (also known as M51a or NGC 5194). Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most famous interacting galaxy pairs.
NGC 5195 was discovered by Pierre Méchain on March 20, 1781.
NGC 5195 and the Whirlpool Galaxy comprise one of the most noted interacting galaxy pairs in astronomy. The two galaxies are listed in the Atlas of Peculiar Galaxies as one of several prominent examples of a spiral galaxy with a companion galaxy. The system was also the subject of very early theoretical investigations into galaxy interactions. The two galaxies are connected by a dust-rich tidal bridge. The dust in this tidal bridge can be seen silhouetted against the center of NGC 5195. This demonstrates that NGC 5195 appears to lie behind the Whirlpool Galaxy. The encounter has significantly enhanced the spiral structure of M51.
In January 2016, BBC science reporter Jonathan Webb said, "Astronomers have spotted two huge waves of gas being 'burped' by the black hole at the heart of a nearby galaxy. The swathes of hot gas, detected in X-ray images from Nasa's Chandra space telescope, appear to be sweeping cooler hydrogen gas ahead of them. This vast, rippling belch is taking place in NGC 5195 - a small, neglected sibling of the 'Whirlpool Galaxy', 26 million light years away. That makes it one of the closest black holes blasting gas in this way". He added, "The findings, presented at the 227th meeting of the American Astronomical Society (AAS) in Florida, are a dramatic example of 'feedback' between a supermassive black hole and its host galaxy". Webb's report cited Marie Machacek, co-author of the study from the Harvard–Smithsonian Center for Astrophysics (CFA), as saying, "We think that feedback keeps galaxies from becoming too large […] But at the same time, it can be responsible for how some stars form. This shows that black holes can create, not just destroy."
...
Wikipedia