Galaxy · Barred spiral
IC 173
IC 173 is a galaxy in the direction of the constellation Cetus, 648.4 million light-years away.
| Type | Barred spiral |
|---|---|
| Constellation | Cetus |
| Distance | 648.4 million light-years (198.80 Mpc) |
| Diameter | 177,200 light-years · 2 × the Milky Way |
| Absolute magnitude | magnitude −22.25 |
| Apparent magnitude | magnitude 14.24 |
| Luminosity | 3.5 × the Milky Way |
| Right ascension (J2000) | 1h 55m 57.1s |
| Declination (J2000) | +1° 17′ 07″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 14.24. Visible from the whole Northern Hemisphere and south to latitude 89° S. 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 648 million years ago. At that time the Earth held only single-celled organisms and the first multicellular life. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 11,502.2 billion years.