Galaxy · Spiral
NGC 4102
NGC 4102 is a galaxy in the direction of the constellation Ursa Major, 39.4 million light-years away.
| Type | Spiral |
|---|---|
| Constellation | Ursa Major |
| Distance | 39.4 million light-years (12.09 Mpc) |
| Diameter | 40,400 light-years · 0.46 × the Milky Way |
| Absolute magnitude | magnitude −19.80 |
| Apparent magnitude | magnitude 10.61 |
| Luminosity | 0.36 × the Milky Way |
| Right ascension (J2000) | 12h 06m 23.1s |
| Declination (J2000) | +52° 42′ 40″ |
| Source | 2MASS Redshift Survey (Huchra et al. 2012) |
In the sky
A telescope is needed to see it: its apparent magnitude is 10.61. Visible from the whole Northern Hemisphere and south to latitude 37° S. North of latitude 37° N it never sets. It stands highest at midnight in March, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 39 million years ago. At that time the dinosaurs were gone and mammals were diversifying; there was no human lineage yet. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 699.5 billion years.