Irregular Galaxy Leo A (Leo III, UGC 5364, DDO 69, A0956), type IBm V,
This galaxy was first cataloged in the DDO survey
(van den Bergh 1966).
Leo A was listed by Yahil et.al. (1977) as
one of six "New Probably Members of the Local Group,"
together with IC 10, IC 5152,
the Aquarius Dwarf, the
Pegasus Dwarf and WLM.
- 09 : 59.4
- +30 : 45
- IBm V
- - 26 km/s
- 2500 kly
- Apparent Dimension:
- 5.1 x 3.1 arc min
- 12.9 mag vis
- Abs. Mag:
Because of its large estimated distance, the dwarf irregular galaxy Leo A
was longly thought to lie at the very edge of the Local Group. Its distance
estimated at about 7 million light-years, it was uncertain if it was actually
a member of the group, although this was indicated by its negative radial
velocity: This small galaxy is approachig us at 26 km/s.
Thus, Kraan-Korteweg and Tammann (1979) lists at as a
probably member galaxy, van den Bergh (1994) has it as
However, a new determination yielded a distance of only 2.5 million light-years
(adjusted to the scale we use here), and thus certainly within the volume
occupied by the Local Group.
Therefore, the new lists of
Mateo (1998) and
van den Bergh (2000) have it as a certain member.
It is slightly more than half-way between the
satellite system of the Milky Way (Milky Way subgroup)
and the outlying NGC 3109 subgroup.
Our photograph of Leo A was obtained by
Deidre A. Hunter of Lowell
Observatory. It is an UBV image, i.e. a combination of images obtained
in the U-band (UV) and assigned blue, B-band (blue) assigned green, and
V-band (visible light) represented red. It was taken from D.A. Hunter's
- Kraan-Korteweg, R.C. & Tammann, Gustav, 1979.
A catalogue of galaxies within 10 MPC.
Astronomische Nachrichten, Vol. 300, p. 181-194
- Mario Mateo, 1998.
Dwarf Galaxies of the Local Group.
Annual Review of Astronomy and Astrophysics, Volume 36, 1998, p. 435-506.
table of Local Group galaxies (NED Level 5)
- Sidney van den Bergh, 1966.
Luminosity Classifications of Dwarf Galaxies.
Astronomical Journal, Vol. 71, p. 922-926
- van den Bergh, Sidney, 1994.
The Outer Fringes of the Local Group.
Astronomical Journal, Vol. 107, No. 4, p. 1328-1332 (April 1994)
- van den Bergh, Sidney, 2000.
Updated Information on the Local Group.
Publications of the Astronomical Society of the Pacific, Vol. 112, No. 770,
p. 529-536 (April 2000)
- A. Yahil, G.A. Tammann, and Allen Sandage, 1977.
The Local Group: The Solar Motion Relative to its Centroid.
Astrophysical Journal, 217:903-915 (Nov 1, 1977)
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Last Modification: June 22, 2003