Interesting factoids you didn’t know about Sirius, ‘The Dog Star’

Sirius, the brightest star in the night sky, also known as “The Dog Star,” is in the ancient constellation of Canis Major, literally meaning “large dog.” Below are a few interesting facts that you may or may not have known about The Dog Star.

Sirius gets its name from the ancient Greek work Seirios, literally meaning “scorcher.” It also goes by other names as well, such as Alpha Canis Majoris, Canicula, and Aschere.

• What you see as a single star is actually a binary star system comprised of a white main sequence star, Sirius A and its white dwarf companion, Sirius B.
• The phrase “dog days of summer” comes from an ancient belief that the Dog Star was somehow responsible for the hot weather because, next to the Sun, it was the largest star in the heavens. The term “Dog Days” was first used by ancient Greeks.
• Ancient Egyptians based their calendars on heliacal rising of Sirius, which is when it first becomes visible above the eastern horizon just before sunrise after a period of not being visible.
• Sirius B is so dim that it cannot be perceived by the naked eye, and was not observed until January 31, 1862 by Alvan Graham Clark. Clark was later honored with the Lalande prize by the French Academy for this discovery.
• Sirius A is approximately 2.02 to 2.14 times the mass of our Sun and about 1.68 to 1.71 its diameter.
• Sirius B, also known as “the Pup” is 8200 times dimmer than its companion, Sirius A, but is actually the hotter of the two.

Fascinating Documentary on the Hubble Space Telescope

YouTube has really changed a lot in the last year or so. I find myself hanging out there more and more these days watching myriad videos on a variety of topics.

A few days ago, I ran across this amazing documentary on the Hubble Space Telescope that was put together by the ESA for public distribution. Astronomy is one of my many passions and I love watching things like this. I hope you will too. The documentary is in 9 parts, (10 videos all together), but I have compiled a playlist at YouTube, so you can click the link below and watch the entire thing without having to click anything again, (when one video finishes, the next will automatically begin). Enjoy.

Hubble Space Telescope Playlist

A View of Earth From Mars

This is the first image ever taken of Earth from the surface of a planet beyond the Moon. It was taken by the Mars Exploration Rover Spirit one hour before sunrise on the 63rd Martian day, or sol, of its mission. (March 8, 2004)

The image is a mosaic of images taken by the rover's navigation camera showing a broad view of the sky, and an image taken by the rover's panoramic camera of Earth. The contrast in the panoramic camera image was increased two times to make Earth easier to see. The inset shows a combination of four panoramic camera images zoomed in on Earth. The arrow points to Earth. Earth was too faint to be detected in images taken with the panoramic camera's color filters.

Credit: NASA/JPL/Cornell/Texas A

via Flickr