Polaris
What is Polaris?
Stars· Distance ~445 ly · size ~46× Sun. The star our axis points at — the whole sky appears to wheel around it, guiding navigators for millennia. Track it in Sky view to see the celestial axis.
📍 Visible from where you are right now — computed in your browser
bearing · altitude · rise time · best time tonight
Where Polaris is in your sky right now: https://nowsky.org/solar/sky?sel=polaris — location and time set automatically, no login.
Distance and spectral type
Polaris is about 433 light-years away, a yellow-white star (spectral type F7:Ib-II), in the constellation Ursa Major. Its apparent magnitude is 2, visible to the naked eye.
Stellar figures
| Distance | ~445 ly (estimates 323–445, debated) |
|---|---|
| Constellation | Ursa Minor |
| Note | within 0.7° of the celestial pole |
Figures are representative approximations. Source: compiled from NASA and IAU public data.
Behind the name
Latin "pole star". It sits 0.7° from the pole; around 3000 BC the role belonged to Thuban in Draco.
Frequently asked
- How far is Polaris from Earth?
- ~445 ly (estimates 323–445, debated).
- What is notable about Polaris?
- within 0.7° of the celestial pole.
- Which constellation is Polaris in?
- Ursa Major.
- Where is Polaris in the sky right now?
- Open the sky view for your location and time and it shows the position in the sky right now.
A heartbeat that faded and came back
Polaris is a Cepheid whose brightness pulses on a four-day cycle. Through the twentieth century that pulse kept shrinking — an amplitude of 0.1 magnitude around 1900 fell to 0.02 by the 1990s, and it was predicted to become the first Cepheid ever to stop pulsating. Then in the 2000s the amplitude began to grow again, and the reason has not been settled.
The period changes too, lengthening by four or five seconds a century, which fits Cepheid theory for a star swelling as it evolves. There is also a claim that Polaris is brighter now than in old records — Ptolemy listed it as 3rd magnitude and it is now 2nd — read by some as a 2.5-fold brightening in two thousand years. The paradox is that the nearest Cepheid, the first rung of the cosmic distance ladder, is the least steady ruler of them all.
The star in depth
Polaris is a compass made by coincidence: Earth's axis happens to point within 0.7° of it, so the whole sky seems to wheel around this one star. For millennia, sailors read their latitude from its height alone.
It is actually a Cepheid variable in a triple system about 445 light-years away — and Cepheids, with their period-luminosity law, were the first ruler for measuring the universe. The guide star doubles as a cosmic yardstick.
Precession makes the title a lease: Thuban held it around 3000 BC, and Vega takes over in ~12,000 years. Use 'track Polaris' in the Sky view to see the celestial axis for yourself.
Polaris's distance long vexed astronomers — despite being a calibration star for the Cepheid distance ladder, estimates ranged from 323 to 445 light-years, since Polaris is too bright for Gaia's detectors and its Hipparcos parallax (433 ly) was disputed by binary-orbit analyses. It shows how delicate cosmic surveying is. Meanwhile the old sailor's rule still opens every navigation textbook: the pole star's altitude is your latitude.
Related
Figures are representative approximations. Simulated positions use J2000 mean elements.