Galaxy · Irregular
Sag dIr
Sag dIr is a galaxy in the direction of the constellation Sagittarius, 3.39 million light-years away.
| Type | Irregular |
|---|---|
| Constellation | Sagittarius |
| Distance | 3.39 million light-years (1.04 Mpc) |
| Diameter | 3,196 light-years · 0.037 × the Milky Way |
| Absolute magnitude | magnitude −12.10 |
| Apparent magnitude | magnitude 12.99 |
| Luminosity | 3.0 × 10⁻⁴ × the Milky Way |
| Right ascension (J2000) | 19h 29m 59.0s |
| Declination (J2000) | −17° 40′ 41″ |
| Source | Updated Nearby Galaxy Catalog (Karachentsev et al. 2013) |
In the sky
A telescope is needed to see it: its apparent magnitude is 12.99. Visible from the whole Southern Hemisphere and north to latitude 72° N. South of latitude 72° S it never sets. It stands highest at midnight in July, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out 3.4 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 60.2 billion years.