Spiral galaxy · Ursa Major

M108

Also known as: NGC 3556

mag 10.09′ across

About

M108 is a spiral galaxy of magnitude 10.0 in Ursa Major, about 9′ across.

M108 is in the constellation Ursa Major.
Best evenings: around late April 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 24° S.

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.

EyesNot visible to the naked eye.
Binoculars (10×50)Too faint for binoculars.
Telescope (6–8 inch)A faint oval glow with a brighter middle — no spiral arms without a camera.

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

Designations	M108, NGC 3556, PGC 34030, UGC 6225
Type	Spiral galaxy (Sc)
Magnitude	10.0The smaller the number, the brighter.
Apparent size	9′ × 3.8′position angle 79°; the full Moon is 31′ across
Surface brightness	21.7 mag/arcsec²Average over its disc, in the blue band: the lower the number, the easier it is to see.
Constellation	Ursa Major
Right ascension (J2000)	11h 11m 31.0s
Declination (J2000)	+55° 40′ 27″