Double star · Ursa Major
M40 Winnecke 4
mag 8.0
About
M40 (Winnecke 4) is a double star of magnitude 8.0 in Ursa Major.
How to find it
- M40 is in the constellation Ursa Major.
- Best evenings: around mid-May 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 22° 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.
What you will see
- EyesNot visible to the naked eye.
- Binoculars (10×50)Probably a single point of light; a telescope splits it.
- Telescope (6–8 inch)Splits into two or more stars at modest power.
For a dark country sky with no Moon. From a city, faint galaxies and nebulae can disappear completely.
Facts
| Designations | M40 |
|---|---|
| Type | Double star |
| Magnitude | 8.0The smaller the number, the brighter. |
| Constellation | Ursa Major |
| Right ascension (J2000) | 12h 22m 16.1s |
| Declination (J2000) | +58° 05′ 04″ |
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M82Cigar GalaxyGalaxy · mag 8.4.jpg?width=160)
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M108Galaxymag 10.0
M97Owl NebulaPlanetary nebula · mag 11.2.jpg?width=160)
NGC 3077The Garland GalaxyGalaxy · mag 9.9
NGC 2841Tiger's Eye GalaxyGalaxy · mag 10.2Sources and credits
Catalog data: OpenNGC by Mattia Verga, CC BY-SA 4.0, and d3-celestial by Olaf Frohn, BSD 3-Clause. All data sources →