Red giant · Eridanus
τ⁴ Eridani
Also known as: τ⁴ Eri, HIP 15474
mag 3.7310 light-years
About
τ⁴ Eridani is a red giant of magnitude 3.7 in Eridanus, about 310 light-years away.
How to find it
- τ⁴ Eridani is in the constellation Eridanus.
- Best evenings: around late December it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
- Where on Earth: it is seen well, at least 10° up, from south of 58° N.
When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.
What you will see
- EyesVisible from the suburbs on a clear night, but lost in bright city skies.
- Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
- Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.
Stars look the same in any instrument: brighter and sharper, but never bigger.
Facts
| Designation | τ⁴ Eridani (τ⁴ Eri) |
|---|---|
| Hipparcos number | HIP 15474 |
| Type | Red giant |
| Spectral type | M3/M4III |
| Colour | Orange-redB−V colour index 1.61 |
| Magnitude | 3.7The smaller the number, the brighter. |
| Distance | 310 light-yearsThe light you see left it around 1720. |
| Proper motion | 0.061″ per year across the sky |
| Constellation | Eridanus |
| Right ascension (J2000) | 03h 19m 31.0s |
| Declination (J2000) | −21° 45′ 28″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →