Galaxy · Spiral
NGC 1643
NGC 1643 is a galaxy in the direction of the constellation Eridanus, 227.2 million light-years away.
| Type | Spiral |
|---|---|
| Constellation | Eridanus |
| Distance | 227.2 million light-years (69.67 Mpc) |
| Diameter | 73,100 light-years · 0.84 × the Milky Way |
| Absolute magnitude | magnitude −20.86 |
| Apparent magnitude | magnitude 13.36 |
| Luminosity | 0.96 × the Milky Way |
| Right ascension (J2000) | 4h 43m 43.9s |
| Declination (J2000) | −5° 19′ 10″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 13.36. Visible from the whole Southern Hemisphere and north to latitude 85° N. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 227 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 4,031.0 billion years.