Galaxy · Spiral
IC 243
IC 243 is a galaxy in the direction of the constellation Cetus, 336.3 million light-years away.
| Type | Spiral |
|---|---|
| Constellation | Cetus |
| Distance | 336.3 million light-years (103.10 Mpc) |
| Diameter | 166,500 light-years · 1.9 × the Milky Way |
| Absolute magnitude | magnitude −21.64 |
| Apparent magnitude | magnitude 13.43 |
| Luminosity | 2 × the Milky Way |
| Right ascension (J2000) | 2h 38m 32.2s |
| Declination (J2000) | −6° 54′ 08″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 13.43. Visible from the whole Southern Hemisphere and north to latitude 83° N. 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 336 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 5,965.2 billion years.