Draco dwarf galaxy

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Galaxy
Dwarf Draco Galaxy
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PGC 60095 Draco Dwarf Hubble WikiSky.jpg
Hubble image of the central area of ​​the Draco dwarf galaxy
AladinLite
Constellation Dragon
Position
equinox :  J2000.0 , epoch : J2000.0
Right ascension 17 h 20 m 06 s
declination + 57 ° 55 '00 ″
Appearance
Morphological type dE0; Peculiar; Dwarf  
Brightness  (visual) +9.9 mag
Angular expansion 51 ′ × 31 ′
Physical data
Affiliation Local group  
distance ~ 280,000  ly  
Absolute brightness -9 likes
diameter approx. 3000 to 3500 ly
history
discovery Albert G. Wilson
Discovery date 1954
Catalog names
UGC  10822 • PGC  60095 • DDO 208 • Anon 1719 + 57

The Draco dwarf galaxy is an elliptical dwarf galaxy, belongs to the local group and is a companion of the Milky Way at only 280,000 light years away. The number of stars in the Draco dwarf galaxy is estimated to be around three million. It was discovered by Albert G. Wilson at the Lowell Observatory in 1954 . Her name is derived from her position, as she is in the constellation Draco (lat. Dragon).

properties

The galaxy was examined for variable stars by Walter Baade , Henrietta Hill Swope and Paul William Hodge in 1961 and 1964, respectively . More than 260 stars were identified as such. Except for 5 stars these were all of the type RR Lyrae . For their observations they used the Oschin Schmidt telescope on Mount Palomar .

Recent studies of the Draco dwarf galaxy have shown a high velocity dispersion far outwards, as well as a large mass-light ratio and suggest that the galaxy is surrounded by a large halo of dark matter , which should be significantly larger than the size of its visible part . The Draco dwarf galaxy will continue to be an interesting research subject in this regard and could provide more information about the nature of dark matter.

additional

Web links

Commons : Constellation Dragon  - Collection of images, videos and audio files

Individual evidence

  1. Jump up ↑ Mark I. Wilkinson, Jan T. Kleyna, N. Wyn Evans, Gerad F. Gilmore, Michael J. Irwin, Eva K. Grebel: Kinematically Cold Populations at Large Radii in the Draco and Ursa Minor Dwarf Spheroidal Galaxies . In: Astronomical Journal . 611, 2004, pp. L21-L24. bibcode : 2004ApJ ... 611L..21W . doi : 10.1086 / 423619 .