Enjoying EarthSky? Subscribe.

164,509 subscribers and counting ...

Kochab and Pherkad in Little Dipper

Kochab and Pherkad

Tonight for April 10, 2015

Tonight, find the stars Kochab and Pherkad in the Little Dipper.

Can’t ever find the Little Dipper you say? Not surprising. It’s fainter and looks less like a dipper than the Big Dipper.

Just notice that – if you draw an imaginary line between the two outer stars in the bowl of the Big Dipper – and extend that line northward on the sky’s dome, you’ll come to Polaris, the North Star. Polaris is part of the Little Dipper. It marks the end of the Little Dipper’s handle. Kochab and Pherkad are the two outer stars in the bowl of the Little Dipper.

The Big Dipper appears high in the northeast sky at nightfall on spring evenings. It wheels above Polaris at late evening.

Our annual fund-raising campaign ends April 16. Help EarthSky keep going!

Chart via IAU, skyandtelescope.com, Wikimedia Commons.

Chart via IAU, skyandtelescope.com, Wikimedia Commons.

Polaris is special because Earth’s axis nearly points to its location in the sky. Polaris is less than a degree away from the true north celestial pole on the sky’s dome now. It’ll be closest to true north – less than half a degree away – in the year 2102. The change is due to a motion of Earth called “precession,” which causes Earth’s axis to trace out a circle among the stars every 26,000 years.

Thousands of years ago, Polaris was an ordinary star in the northern sky, known to the Greeks by the name “Phoenice.”

Other ordinary stars in the northern sky now – Kochab and Pherkad in the Little Dipper – have had the honor of being pole stars.

Kochab and Pherkad served as twin pole stars from about 1500 BC to about 500 BC. They are still sometimes called the Guardians of the Pole.

Kochab is located about 126 light-years away. Pherkad is more distant, at about 480 light-years by some estimates. Polaris is a bit more than 400 light-years away.

Bottom line: Kochab and Perkad are in the Little Dipper asterism. You say you can find the Big Dipper but not the Little Dipper? This post will help.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us