Enjoying EarthSky? Subscribe.

137,540 subscribers and counting ...


Posts by Larry Sessions

Procyon
Tonight | Feb 23, 2015

Star of the week: Procyon the Little Dog Star

The Dog Star, Sirius, is easy to spot because it’s the sky’s brightest star. Procyon – the other Dog Star – is always near its brighter brother on the sky’s dome.

Castor system via Jeremy Perez
Tonight | Feb 16, 2015

Castor six stars in one

Two stars noticeable for being bright and close together might be Castor and Pollux of the Gemini Twins constellation.

Photo Credit:  A. Dupree, R. Gilliland, NASA
Blogs | Feb 10, 2015

How far is Betelgeuse?

Finding star distances isn’t easy. Here’s how it’s done, and why astronomers recently modified the distance estimate to the famous star Betelgeuse.

Canopus seen from ISS
Tonight | Feb 06, 2015

Will you see Canopus?

Canopus is sky’s second-brightest star and easy to spot on February evenings, if …

Betelgeuse imaged in ultraviolet light by the Hubble Space Telescope and subsequently enhanced by NASA. The bright white spot is likely one of this star's poles. Image via NASA/ESA.
Tonight | Jan 29, 2015

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.

Capella system, via Atlas of the Universe
Tonight | Jan 13, 2015

Capella is two golden stars

We see Capella as the brightest star in the constellation Auriga the Charioteer. It is really two stars, each with a golden color similar to our sun.

11jan10_430
Tonight | Jan 09, 2015

Faint, fuzzy object near Sirius is a star cluster

Throughout January, look for a faint fuzzy object near the bright star Sirius. It’s called M41, and it’s a star cluster masquerading as a comet.

Blue-white Rigel via Clark Planetarium
Tonight | Jan 06, 2015

Rigel in Orion is blue-white

We couldn’t live as close to Rigel as we live to our sun, because Rigel is nearly twice as hot – and about 40,000 times brighter – than our local star.

Aldebaran-Sun_comparison_cropped
Tonight | Dec 29, 2014

Aldebaran is the Bull’s fiery eye

If Aldebaran were placed where the sun is now, its surface would extend almost to the orbit of Mercury.

large_magellanic_cloud2
Tonight | Dec 26, 2014

Large Magellanic Cloud is spectacular from Earth’s Southern Hemisphere

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