Galaxy · Spiral
Pinwheel (M101)
Pinwheel (M101) is a galaxy in the direction of the constellation Ursa Major, 20.9 million light-years away. A face-on giant spiral almost twice the size of the Milky Way.
| Type | Spiral |
|---|---|
| Constellation | Ursa Major |
| Distance | 20.9 million light-years (6.40 Mpc) |
| Diameter | 169,600 light-years · 1.9 × the Milky Way |
| Absolute magnitude | magnitude −21.50 |
| Apparent magnitude | magnitude 7.53 |
| Luminosity | 1.7 × the Milky Way |
| Right ascension (J2000) | 14h 03m 12.5s |
| Declination (J2000) | +54° 20′ 56″ |
| Source | Compiled catalogue (NED, approximate values) |
In the sky
Too faint for the naked eye (magnitude 7.53); binoculars will find it. Visible from the whole Northern Hemisphere and south to latitude 36° S. North of latitude 36° N it never sets. It stands highest at midnight in April, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 21 million years ago. At that time the dinosaurs were gone and mammals were diversifying; there was no human lineage yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 370.3 billion years.