Galaxy · Barred spiral
NGC 721
NGC 721 is a galaxy in the direction of the constellation Andromeda, 260.8 million light-years away.
| Type | Barred spiral |
|---|---|
| Constellation | Andromeda |
| Distance | 260.8 million light-years (79.96 Mpc) |
| Diameter | 193,200 light-years · 2.2 × the Milky Way |
| Absolute magnitude | magnitude −21.19 |
| Apparent magnitude | magnitude 13.32 |
| Luminosity | 1.3 × the Milky Way |
| Right ascension (J2000) | 1h 54m 45.5s |
| Declination (J2000) | +39° 23′ 01″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 13.32. Visible from the whole Northern Hemisphere and south to latitude 51° S. North of latitude 51° N it never sets. It stands highest at midnight in October, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 261 million years ago. At that time complex animals were spreading through the seas and over the land; there were no dinosaurs yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4,626.3 billion years.