Dwarf Spheroidal Galaxy Candidate Willman 1 (Ursa Major I, SDSSJ1049+5103),
type dSph, or Globular Cluster,
in Ursa Major
Discovered in 2004 by Willman et.al.
- 10 : 49.4
- + 51 : 03
- dSph ? Globular Cluster ?
- 147 kly
- Apparent Dimension:
- 1.75 arc min
- 15.3 mag vis
- Abs. Mag:
This dwarf galaxy was discovered in 2004 as an overdensity of red, resolved
stars in the Sloan Digital Sky Survey, by a team of astronomers led by Beth
Willman (Willman et.al. 2005). At the time
of its discovery, it was the intrinsically faintest and lowest surface
brightness dwarf galaxy known, more than five times less luminous than the
faintest previously known dSph dwarfs, i.e. And IX,
the Draco Dwarf and the
Ursae Minor Dwarf. This has given rise to
speculations if this was a new sort of objects between dwarf galaxies and
globular clusters, or a new candidate for "Cold Dark Matter" in the universe
(e.g. Kleyna et.al. 2005).
.. more to come soon ..
- Jan T. Kleyna, Mark I. Wilkinson, N. Wye Evans, and
Gerard Gilmore, 2005.
Ursa Major: A Missing Low-Mass CDM Halo?
Astrophysical Journal, Vol. 630, Issue 2, pp. L141-L144 (September 2005)
[ADS: 2005ApJ...630L.141K] -
- Beth Willman, Julianne J. Dalcanton,
David Martinez-Delgado, Andrew A. West, Michael B. Blanton, David W. Hogg,
J.C. Barentine, Howard J. Brewington, Michael Harvaner, S.J. Kleinman,
Jurek Krzesinski, Dan Long, Eric H. Nelson, Jr., Atsuko Nitta, and
Stefanie A. Snedden, 2005.
A New Milky Way Dwarf Galaxy in Ursa Major.
Astrophysical Journal, Vol. 626, Issue. 2, pp. L85-L86 (June 2005)
[ADS: 2005ApJ...626L..85W] -
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Last Modification: February 14, 2005