Star · M4V
CFHT-Hy-21
CFHT-Hy-21 is a main-sequence star of spectral type M4V in the constellation Taurus, 127.2 light-years from the Sun.
| Constellation | Taurus |
|---|---|
| Distance | 127.2 light-years (39.0 pc) |
| Apparent magnitude | magnitude 25.84 |
| Absolute magnitude | magnitude 22.88 |
| Spectral type | M4V |
| Surface temperature | 2,980 K |
| Luminosity | 1.10 × 10⁻⁶ L☉ |
| Radius | 0.00395 R☉ |
| Mass | 0.075 M☉ (estimated) |
| Right ascension (J2000) | 4h 29m 22.8s |
| Declination (J2000) | +15° 35′ 30″ |
| Space velocity (relative to the Sun) | 21.4 km/s |
In the sky
A telescope is needed to see it: its apparent magnitude is 25.84. Visible from the whole Northern Hemisphere and south to latitude 74° S. North of latitude 74° N it never sets. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1899. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.3 million years.
The Sun seen from there
From a planet around CFHT-Hy-21, the Sun would look like a star of magnitude 7.79, in the direction where our sky has the constellation Ophiuchus. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 21543 4.47 light-years
- θ¹ Tau 4.58 light-years
- HIP 20719 6.17 light-years
- HIP 20485 8.60 light-years
- HIP 20745 10.3 light-years
- HIP 19767 11.5 light-years
- HIP 19472 11.5 light-years
- HIP 20679 11.8 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.