Star Stars · In Grus
Tiaki
Tiaki, β Gruis, is a red giant in Grus: the 60th brightest star in the night sky.
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- Constellation
- Grus
- Designation
- β Gruis
- Apparent magnitude
- 2.07 · 60th brightest star in the night sky
- Spectral class
- M5III
- Distance
- 177 light-years
- Highest at midnight
- late August
- Position (J2000)
- RA 22h 43m · Dec −46° 53′
A red giant, around 3,100 K, like Betelgeuse and Antares. About 59× brighter than the faintest star the eye can see. Gives off about 370 times the Sun's visible light. The light you are seeing left around 1849.
When to see it
On the night of Mon 30 Aug 2027, when it is highest around midnight, on each city’s own clock:
| From | Rises | Highest | Sets |
|---|---|---|---|
| London GMT+1 | Never rises | ||
| New York EDT | 23:28 | 01:03 · 3° | 02:39 |
| Singapore GMT+8 | 19:21 | 01:14 · 42° | 07:07 |
| Sydney GMT+10 | 15:04 | 00:05 · 77° | 09:05 |
Common questions
- Can I see it from 50° north?
- No. From there it never rises: you would have to travel south of 43° north before it cleared the horizon at all.
- Can I see it from 35° south?
- Yes. It rises and sets, and at its highest it stands 78° up in the south.
- When is the best time of year to see it?
- Around late August, when it stands opposite the Sun and is highest at midnight. It comes round about two hours earlier each month, so by late November it is highest in the early evening, and in late May not until the hours before dawn.
- How far away is it, and how bright?
- It is 177 light-years away, and shines at magnitude 2.07 in our sky. From that far, the Sun would be a star of magnitude 8.5: too faint for the eye, a target for binoculars.
- Naked eye, binoculars or telescope?
- The naked eye, even from a city: at magnitude 2.07 it is brighter than the faintest stars a city sky still shows, about magnitude 4.5.
Look for
Start from Alnair: Tiaki is 5.9° east of it, three fingers at arm’s length.
Look for
From 50° north it never rises; from 35° north it barely clears the horizon, at 8°; from the equator it climbs to 43°; from 35° south it climbs to 78°.
Science
Tiaki’s surface is about 3,100 K, some 2,700 K cooler than the Sun’s 5,772 K, so its light is strongest at about 930 nm, in the infrared, past the red end of what the eye can see, where the Sun’s is strongest at 500 nm. Moved to 33 light-years, the distance astronomers compare stars at, it would shine at magnitude −1.6, brighter than Sirius, the brightest star in our sky.
Did you know
Against Alnair, the brighter star the hop starts from: Alnair looks 1.4 times as bright as Tiaki in our sky, but Alnair is 101 light-years away and Tiaki 177 light-years, so side by side Tiaki would give off 2.2 times as much light as Alnair.
Science
Tiaki is the 79th nearest to us of the 156 stars on these pages with a measured distance. Its nearest neighbour among them in space is Lang-Exster, about 51 light-years from it; on our sky the two are 14° apart.
Look for
The Sun passes 35° north of Tiaki around late February, when it is highest at noon, in daylight: the weeks either side are its worst time of year. From 35° north it is above the horizon for about 6 hours a day and from 35° south about 18. It is 58° from the plane of the Milky Way, well away from the band.