Messier 34 (also M 34, NGC 1039 and OCL 382) is a magnitude +5.5 open star cluster located 1,500 light-years away in the constellation Perseus.
The cluster was probably discovered by Italian astronomer Giovanni Battista Hodierna with a with a 20x Galilean telescope in the castle of his patron Carlo Tomasi et Caro, in Palma di Montechiaro sometime before 1654. The galaxy was independently discovered by by French astronomer Charles Messier using a 8.38 cm (3.3 inch) refractor on the night of August 25-26, 1764.
Right Ascension 02h 42m 05.0s, Declination +42° 45' 42"
The age of this cluster lies between the respective ages of the Pleiades open cluster at 100 million years and the Hyades open cluster at 800 million years. Comparisons between the observed stellar spectra and the values predicted by stellar evolutionary models gives an age estimate of 200-250 million years for M34. Read more