Galaxy · Barred spiral
NGC 1721
NGC 1721 is a galaxy in the direction of the constellation Eridanus, 209.7 million light-years away.
| Type | Barred spiral |
|---|---|
| Constellation | Eridanus |
| Distance | 209.7 million light-years (64.29 Mpc) |
| Diameter | 113,000 light-years · 1.3 × the Milky Way |
| Absolute magnitude | magnitude −21.88 |
| Apparent magnitude | magnitude 12.16 |
| Luminosity | 2.5 × the Milky Way |
| Right ascension (J2000) | 4h 59m 17.4s |
| Declination (J2000) | −11° 07′ 07″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.16. Visible from the whole Southern Hemisphere and north to latitude 79° N. South of latitude 79° S it never sets. It stands highest at midnight in December, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 210 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 3,719.7 billion years.