Galaxy · Spiral
NGC 3646
NGC 3646 is a galaxy in the direction of the constellation Leo, 197.9 million light-years away.
| Type | Spiral |
|---|---|
| Constellation | Leo |
| Distance | 197.9 million light-years (60.69 Mpc) |
| Diameter | 201,400 light-years · 2.3 × the Milky Way |
| Absolute magnitude | magnitude −22.54 |
| Apparent magnitude | magnitude 11.38 |
| Luminosity | 4.5 × the Milky Way |
| Right ascension (J2000) | 11h 21m 43.1s |
| Declination (J2000) | +20° 10′ 11″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 11.38. Visible from the whole Northern Hemisphere and south to latitude 70° S. North of latitude 70° N it never sets. It stands highest at midnight in March, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 198 million years ago. At that time dinosaurs ruled the Earth. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 3,511.4 billion years.