Stars Visible from Earth
Space and Astrology 6/19/11
By: Yona Williams
If you're an amateur stargazer, it's probably a good idea to become familiar with some of the celestial objects that you can view with your telescope and naked eye. While you're on the hunt for constellations and bright stars, you should consider the selections in this article that can be spotted from Earth.
Betelgeuse (alpha Orionis)
This star is actually pronounced 'beetle juice' and it holds the honors as being the second-brightest star in the constellation of Orion. This supergiant star is reddish in color and is nearly 1,000 times larger than the Sun. It doesnÃ¢â‚¬â„¢t share the same hot characteristics as the sun, but it's a pretty big object. Positioned 520 light-years from Earth, the star possesses a varying magnitude measured from 0.3 to 1.2 over a period of about 7 years, which averages about 0.70. Betelgeuse stands out because it is the only star (other than the sun) that we have access to surface images.
Known as 'the hunter,' Orion is a constellation associated with the zodiac. Besides, Betelgeuse, it possesses other bright stars, such as Rigel and Bellatrix. This constellation is also the host of the Horsehead Nebula.
Arcturus (Alpha Bootis)
The fourth brightest star in the sky is called Arcturus, which belongs to the constellation Bootes (which represents the herdsmen). Classified as a red giant (spectral type K1.5IIIp), the star is found 34 light-years from Earth. Measurements for the star include an apparent magnitude of -0.04 and an absolute magnitude of 0.2.
Antares (Alpha Scorpii)
When you identify the Scorpio zodiac constellation, the brightest star in Scorpius is Antares, which name translates into "Rival of Mars." Located about 520 light-years from Earth, Antares is around 230 times as big as the Sun. It is classified as an M1.5Iab variable red supergiant star. Overall, the star has earned the title of being the 15th brightest star in the sky. Measurements of brightness for the star include a visual (apparent) magnitude of +0.96 (var.) and an absolute magnitude of -5.2.
Polaris (alpha UMi)
Known as the current pole star for the Northern Hemisphere, blue-green Polaris is 1 degree from the exact location of the Northern celestial pole. Classified as a double star with a faint companion star, it was Sir William Herschel that discovered Polaris in 1780. When the star reaches its highest level of brightness, it is about 6,000 to 10,000 times brighter than our Sun.
Other stars that can be seen from Earth include:
Ã‚Â· Deneb (or alpha Cygni) Ã¢â‚¬â€œ the brightest star in the constellation Cygnus (known as the swan). This supergiant star is situated about 1,500 light years away, and has a bright white color.
Ã‚Â· Rigel (or beta Orionis) Ã¢â‚¬â€œ known as the brightest star in the Orion constellation, and one of the brightest in all the sky. This supergiant is described as extremely hot and blue in color.
Ã‚Â· Sirius Ã¢â‚¬â€œ In Greek, Sirius means 'scorching'. Also referred to as the dog star, Sirius belongs to the constellation called Canis Major (Great Dog).