Enjoying EarthSky? Subscribe.

123,608 subscribers and counting ...

Brightest Stars

Zubeneschamali via nikomi.net
Tonight | Jun 17, 2014

Is Zubeneschamali a green star?

Although some scientists claim stars can’t look green, many stargazers will swear that Zubeneschamali proves otherwise.

Artist's concept of Kochab seen from its planets via ESky
Tonight | Jun 10, 2014

Kochab and Pherkad guard the pole star

Two noticeable stars in the Little Dipper are said to guard the north celestial pole because they circle so close to Polaris.

Zubenelgenubi via AAO/STScI/WikiSky
Tonight | Jun 05, 2014

Zubenelgenubi is Libra’s alpha star

Zubenelgenubi is an Arabic name that means this star was once seen as the Southern Claw of Scorpius the Scorpion.

Polaris, on left, via Taro Yamamoto
Tonight | May 29, 2014

Polaris is the North Star

The entire northern sky wheels around Polaris. Some assume it’s the brightest star in the sky. In fact, Polaris ranks only 50th in brightness.

Alpha Centauri
Tonight | May 20, 2014

Alpha Centauri closest star system to our sun

The third star in the system, a red dwarf called Proxima Centauri, is thought to be about 4.22 light-years distant and is actually our sun’s closest neighbor.

Arcturus.
Tonight | May 13, 2014

Arcturus, orange star, cuts through galaxy’s disk

Arcturus is cutting perpendicularly through the galactic disk at a tremendous rate of speed – some 150 kilometers per second.

Great Pyramid of Giza
Tonight | May 06, 2014

Thuban is a former Pole Star

Thuban was the Pole Star some 5,000 years ago, when the Egyptians were building the pyramids.

Artist's concept of Spica from hypothetical planet
Tonight | Apr 24, 2014

Spica is a whirling double star

Spica is a binary star, with two stars larger and hotter than the sun, telescopically indistinguishable from a single point of light.

Image Credit: ESO Online Digitized Sky Survey
Tonight | Apr 12, 2014

Mizar and Alcor, famous double star, really six stars

Mizar and its fainter companion star Alcor are located in the handle of the Big Dipper. They are one of the sky’s easiest-to-spot double stars.

Cor Caroli by F. Ringwald, Fresno State
Tonight | Apr 09, 2014

Cor Caroli or Heart of Charles

The star Cor Caroli, or Alpha Canum Venaticorum, is a binary star and the brightest star in the northern constellation Canes Venatici.