Messier 39 is a bright open star cluster located in the constellation Cygnus, about 800 to 1,010 light-years away from Earth, and it reaches its annual culmination at astronomical midnight and is best observed in mid August.
Messier 39 is a bright open star cluster located in the constellation Cygnus, about 800 to 1,010 light-years away from Earth, and it reaches its annual culmination at astronomical midnight and is best observed in mid August.