© Massimo Di Fusco
The Dragon Dwarf, also known as UGC 10822, is a spherical galaxy discovered by Albert George Wilson in 1954 by analyzing photographic plates from the National Geographic Society’s Palomar Observatory Sky Survey (POSS). It belongs to the Local Group, which is a satellite galaxy of the Milky Way and is about 260,000 light-years away from Earth. The Dragon Dwarf Galaxy contains primarily an old population of stars and a tiny amount of interstellar matter (which is essentially dust-free). 75 to 90% of its stars formed more than about 10 billion years ago, and its central region contains a concentration of metal-rich stars. Recently, dwarf elliptical galaxies have become prime objects for studying dark matter, and UGC 10822 is one of them that has received special attention. Calculations of the radial velocity of this galaxy revealed a large internal velocity dispersion, giving a mass-to-luminosity ratio of 440 m/L☉, indicating the presence of large amounts of dark matter. It has been hypothesized that the large velocity dispersion can be explained by “dwarf tides” (nearly unbound stellar streams from dwarf galaxies disturbed by the Milky Way). However, the narrow horizontal branch width of UGC10822 does not support this pattern. This leaves only the dark matter explanation, and the dragon dwarf is the most dark matter-dominated object we know of.
Data about the image
| Goal | User Content 10822 |
| location | Ferrara |
| time |
04/24/2024 at 00:00 UTC |
| camera | The first player is Poseidon-C |
| Telescope/lens | Cone 200/1000 |
| Multiple | Eq6r Pro |
| Exposure time | 6 pm |
| Post-processing | AB,Bixensight,PS |
View full image
Please allow Javascript to maintain the full functionality of Spektrum.de.
“Alcohol buff. Troublemaker. Introvert. Student. Social media lover. Web ninja. Bacon fan. Reader.”
More Stories
Losing the importance of academic libraries – open access in the sciences – a dubious promise of salvation
Reproduction takes more energy than previously known
Science: Logistics Research of the Future – Digital, Trends, Science and Research | News | Logistics today