Dragonfly 44
| Dragonfly 44 | |
|---|---|
|
Coma-Cluster | |
| Observation data | |
| Constellation | Coma Berenices |
| Right ascension | 13h 00m 58.0s[1] |
| Declination | +26° 58′ 35″[1] |
| Redshift | ~0.023 |
| Helio radial velocity | 6280 ± 120 km/s |
| Distance | ~100 Mpc (~330 Mly) |
| Group or cluster | Coma Cluster |
| Apparent magnitude (V) | 21 mag; or 19.4 mag [1] |
| Apparent magnitude (B) | 22 |
| Absolute magnitude (V) | -16.1 mag [1] |
| Characteristics | |
| Mass | ~1.0×1012 M☉ |
| Size | 70,000 |
| Apparent size (V) | 10 x 35 arcsec |
| Other designations | |
| SDSS J130057.98+265839.6, SDSS J130058.17+265836.1, SDSS J130058.21+265829.3 | |
Dragonfly 44 is an ultra diffuse galaxy in the Coma Cluster.[2][3][1][4] Observations of the rotational speed suggest a mass of about one trillion solar masses, about the same as the mass of the Milky Way. This is also consistent with about 90 globular clusters observed around Dragonfly 44. However, the galaxy emits only 1% of the light emitted by the Milky Way.[5] The galaxy was discovered with the Dragonfly Telephoto Array.[6]
In August 2016, astronomers reported that this galaxy might be made almost entirely of dark matter.[7][8][9]
See also
- Dark galaxy
- Low-surface-brightness galaxy (LSB galaxy)
- Type-cD galaxy or c-Diffuse galaxy type
- Type-D galaxy or Diffuse-type galaxy
References
- 1 2 3 4 5 Van Dokkum, Pieter; et al. (1 May 2015). "Spectroscopic confirmation of the existence of large, diffuse galaxies in the coma cluster". The Astrophysical Journal Letters. Retrieved 1 September 2016.
- ↑ "Scientists discover the fluffiest galaxies". phys.org. 14 May 2015.
- ↑ Van Dokkum, Pieter; et al. (7 January 2015). "Forty-seven milky way-sized, extremely diffuse galaxies in the Coma-Cluster". The Astrophysical Journal Letters. Retrieved 31 August 2016.
- ↑ Dragonfly 44: Ultra-Diffuse Galaxy Made Mostly of Dark Matter. Aug 2016
- ↑ Crosswell, Ken (26 July 2016). "The Milky Way's dark twin revealed". Nature News. Retrieved 30 July 2016.
- ↑ Rachel Feltman (25 August 2016). "A new class of galaxy has been discovered, one made almost entirely of dark matter". Washington Post.
- ↑ Van Dokkum, Pieter; et al. (25 August 2016). "A High Stellar Velocity Dispersion and ~100 Globular Clusters For The Ultra-Diffuse Galaxy Dragonfly 44". The Astrophysical Journal Letters. Retrieved 27 August 2016.
- ↑ Hall, Shannon (25 August 2016). "Ghost galaxy is 99.99 per cent dark matter with almost no stars". New Scientist. Retrieved 27 August 2016.
- ↑ Feltman, Rachael (26 August 2016). "A new class of galaxy has been discovered, one made almost entirely of dark matter". The Washington Post. Retrieved 26 August 2016.
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