The cluster is shown
rotated 143° counterclockwise.
Discovered 1745-46 by
Philippe Loys de Chéseaux.
M71 is at a distance
of about 13,000 light years from Earth and spans some 27 light
M71 was long thought
(until the 1970's) to be a densely packed open cluster. Modern
photometric photometry detected a short horizontal branch in the
H-R diagram of M71, which is characteristic of a globular
cluster. So today, M71 is designated as a very loosely concentrated
M71 is a wonderful
example of how galactic extinction effects color. The cluster has a
galactic latitude of only -4.6°. This means we view it through much
dust and nebulae. This causes the color to shift towards the red,
just like the Sun at sunset. Place your mouse over the image to see
about how the cluster would look without the intervening dust.