Enjoying EarthSky? Subscribe.

270,824 subscribers and counting ...

Larry Sessions

Capella is 2 golden stars

We see Capella as the brightest star in the constellation Auriga the Charioteer. It’s actually 2 stars, each with a golden color similar to our sun.

Rigel in Orion is blue-white

Blue-white Rigel, in the constellation Orion, is one of the brightest stars in the night sky. It’s about twice as hot, and 40,000 times brighter, than our sun.

Leap second to be added December 31

Delay those New Year’s plans. World timekeepers will add a leap second just before midnight on December 31, 2016.

Aldebaran is the Bull’s fiery eye

Aldebaran – brightest star in the constellation Taurus the Bull – is huge! If it were in our sun’s place, its surface would extend almost to the orbit of Mercury.

Betelgeuse will explode someday

Someday, the star Betelgeuse will run out of fuel, collapse under its own weight, and then rebound in a spectacular supernova explosion. Someday … but probably not soon.

Was the Christmas Star real?

Was there really a star that led the 3 wise men to Bethlehem?

The spectacular Large Magellanic Cloud

From tropical or Southern Hemisphere latitudes, the Large Magellanic Cloud is easy to see. Look for it in the evening from December to April.

Super effect on us from a supermoon?

A supermoon’s pull of gravity creates higher-than-usual tides. But gravity doesn’t affect a human body as much as it does an ocean tide.

Achernar is the End of the River

Achernar – also known as Alpha Eridani – is the 9th brightest star in Earth’s sky and the flattest star known.

Quarter moon or a half moon?

Half the moon always faces us. And half the moon is always lit by the sun. But, in the language of astronomers, there are no ‘half moons.’