Open cluster · Cygnus

M39

Also known as: NGC 7092

mag 4.632′ across

About

M39 is an open cluster of magnitude 4.6 in Cygnus, about 32′ across.

M39 is in the constellation Cygnus.
Best evenings: around late September it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
Where on Earth: it is seen well, at least 10° up, from north of 32° S.
Northern Cross: A loose, bright cluster 9° north-east of Deneb; binoculars.

When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.

EyesA faint smudge at the limit of vision, only from a dark site.
Binoculars (10×50)A rich scattering of stars — binoculars often give the best view.
Telescope (6–8 inch)Dozens of stars, many sharp and some coloured.

For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.

Designations	M39, NGC 7092
Type	Open cluster
Magnitude	4.6The smaller the number, the brighter.
Apparent size	32′the full Moon is 31′ across
Constellation	Cygnus
Right ascension (J2000)	21h 31m 48.3s
Declination (J2000)	+48° 26′ 18″