Messier 47

Description and Details: Messier 47 (also known as M47 or NGC 2422) is a bright open star cluster located in the southern constellation Puppis that lies at a distance of 1600 light years from Earth and has an apparent magnitude of 4.2. M47 occupies an area of 30 arc minutes of apparent sky, corresponding to a linear diameter of 12 light years, and its estimated age is 78 million years.
The cluster is located close to Messier 46 (about a degree to the southeast), a considerably older and more distant open cluster. M46 has significantly more stars, but appears much dimmer because it lies at a greater distance from Earth.
Messier 47 contains about 50 members, which makes it one of the least densely populated open clusters known. The cluster contains many luminous blue stars and a few older red giants. The brightest stars in M47 have a visual magnitude of 5.7 and the single brightest star in the cluster is of the spectral type B2. The cluster also contains two K-type orange giants, each about 200 times more luminous than the Sun.
A close binary star, Sigma 1121, lies near the centre of M47. It is composed of two magnitude 7.9 stars that are separated by 7.4 arc seconds.
The cluster was discovered by the Italian astronomer Giovanni Battista Hodierna before 1654. Hodierna described it as “a Nebulosa between the two dogs.” His discovery, however, did not come to light until the 1980s because his work was largely forgotten for a few centuries.
Charles Messier independently discovered the cluster on February 19, 1771.

Data acquired at Chilescope
ASA Newton 500 @1900mm, f/3.8
ASA DDM85 equatorial mount
FLI PL16803 CCD camera
Astrodon R/G/B filters 3x(3x300")
APP, PixInsight, PS

Name: Massimo Di Fusco