Star · M3
Gl 661B
Gl 661B is a main-sequence star of spectral type M3 in the constellation Hercules, 20.6 light-years from the Sun.
| Constellation | Hercules |
|---|---|
| Distance | 20.6 light-years (6.32 pc) |
| Apparent magnitude | magnitude 10.40 |
| Absolute magnitude | magnitude 11.40 |
| Spectral type | M3 |
| Surface temperature | 3,850 K |
| Luminosity | 0.00804 L☉ |
| Radius | 0.201 R☉ |
| Mass | 0.233 M☉ (estimated) |
| Right ascension (J2000) | 17h 12m 07.8s |
| Declination (J2000) | +45° 39′ 56″ |
| Space velocity (relative to the Sun) | 44.8 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 10.40. Visible from the whole Northern Hemisphere and south to latitude 44° S. North of latitude 44° N it never sets. It stands highest at midnight in June, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 2005. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 366 thousand years.
The Sun seen from there
From a planet around Gl 661B, the Sun would look like a star of magnitude 3.83, in the direction where our sky has the constellation Pictor. It would be visible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- Gl 661A 1.13 light-years
- GJ 625 4.18 light-years
- GJ 3991 4.24 light-years
- Gl 623 6.04 light-years
- Vega 8.07 light-years
- WISEPA J173835.53+273258.9 8.26 light-years
- WISEPA J174124.26+255319.5 8.32 light-years
- GJ 687 9.03 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.