Winnecke 4 (M40)

Also known as M40 · M 40 · Winnecke 4 · M040

Winnecke 4 (M40) is a double star in the constellation Ursa Major.

Open it on the live sky map Plan Night Exploration

Winnecke 4 (M40): a sky-survey photograph of its field — Sky survey view (DSS2 colour, or a backup survey)

Facts

Type	Double star
Constellation	Ursa Major
Position (J2000)	12h 22m 16s, +58° 05′
Brightness	magnitude 8 (smaller is brighter; the faintest stars the eye sees are about 6)
Studied in	10 scientific papers (SIMBAD)

When and how to see it

Winnecke 4 (M40) is highest in the sky at midnight in March. From India (about 20° N) it climbs to about 52° above the horizon; from 50° N, to about 82°. To see it you need binoculars.

Heights are worked out for India and for 50° N. Set your location in Settings to see them for where you are.

For tonight's best time from your own town, the darkness and the Moon, open it on the map and see its "Tonight from your location" card.

More in Ursa Major

Everything in Ursa Major · All 88 constellations · All sky objects

Data: SIMBAD (CDS, Strasbourg; the site's weekly copy) · OpenNGC · Data sources & credits