Alhena
star · Gemini · 1.9ᵐ
White star in Gemini.
Notable facts
The light you see today left Alhena around the year 1917.
About 42 times brighter than the faintest star visible to the naked eye.
In brief
Which constellation is Alhena in?
Alhena lies in Gemini.
Is Alhena visible to the naked eye?
1.9ᵐ — visible to the naked eye (under dark skies).
When is the best time to observe Alhena?
Best observed in December.
Data
- RA / Dec (J2000)
- 6h 38m · +16° 24′
- Type
- star
- Constellation
- Gemini
- How to observe
- 1.9ᵐ — visible to the naked eye (under dark skies)
- Spectral class
- A0IV — white star
- Absolute magnitude
- -0.7ᵐ
- Luminosity
- ≈163 × the Sun
- Distance
- ~109 light years
- Designation
- HIP 31681
Observing tip
Stars stay points at any magnification: aim your telescope for colour, brightness and companions, not detail.
Altitude above the horizon by latitude
| Latitude | Maximum altitude | Rise azimuth |
|---|---|---|
| +60° | 46° | 56° |
| +55° | 51° | 61° |
| +45° | 61° | 66° |
| +30° | 76° | 71° |
| 0° | 74° | 74° |
| −35° | 39° | 70° |
Geometric altitude at upper culmination, atmospheric refraction not included. Positive latitudes are in the northern hemisphere.
Culmination time by month
| Month | Culmination |
|---|---|
| January | 22:52 |
| February | 20:45 |
| March | 19:00 |
| April | 17:06 |
| May | 15:12 |
| June | 13:06 |
| July | 11:02 |
| August | 09:01 |
| September | 07:08 |
| October | 05:19 |
| November | 03:18 |
| December | 01:10 |
Upper culmination in local solar time — no time-zone or daylight-saving correction applied.