White main-sequence star · Cassiopeia
θ Cassiopeiae
Also known as: θ Cas, HIP 5542
mag 4.3130 light-years
About
θ Cassiopeiae is a white main-sequence star of magnitude 4.3 in Cassiopeia, about 130 light-years away.
How to find it
- θ Cassiopeiae is in the constellation Cassiopeia.
- Best evenings: around late November 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 north of 25° S.
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 | θ Cassiopeiae (θ Cas) |
|---|---|
| Hipparcos number | HIP 5542 |
| Type | White main-sequence star |
| Spectral type | A7Vvar |
| Colour | Yellowish whiteB−V colour index 0.17 |
| Magnitude | 4.3The smaller the number, the brighter. |
| Distance | 130 light-yearsThe light you see left it around 1890. |
| Proper motion | 0.23″ per year across the sky |
| Constellation | Cassiopeia |
| Right ascension (J2000) | 01h 11m 06.1s |
| Declination (J2000) | +55° 09′ 00″ |
Sources and credits
Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →