Kitt Peak Nightly Observing Program
Splendors of the Universe on YOUR Night!
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The Big Dipper (also known as the Plough) is an asterism consisting of the seven brightest stars of the constellation Ursa Major. Four define a “bowl” or “body” and three define a “handle” or “head”. It is recognized as a distinct grouping in many cultures. The North Star (Polaris), the current northern pole star and the tip of the handle of the Little Dipper, can be located by extending an imaginary line from Big Dipper star Merak (β) through Dubhe (α). This makes it useful in celestial navigation.
Constellation Ursa Minor is colloquially known in the US as the Little Dipper, because its seven brightest stars seem to form the shape of a dipper (ladle or scoop). The star at the end of the dipper handle is Polaris, the North Star. Polaris can also be found by following a line through two stars in Ursa Major—Alpha and Beta Ursae Majoris—that form the end of the ‘bowl’ of the Big Dipper, for 30 degrees (three upright fists at arms’ length) across the night sky.
M104 (Sombrero Galaxy)
M51 Whirlpool Galaxy
M51, the Whirlpool Galaxy, gets its name from its bright and prominent spiral arms. It lies at a distance of 23 million light-years away. It also has a smaller, companion galaxy (NGC 5195). The two galaxies are one of the best examples of interacting galaxies.
M13 Hercules Globular
M13, the “Great Globular Cluster in Hercules” was first discovered by Edmund Halley in 1714, and later catalogued by Charles Messier in 1764. It contains 300,000 stars, and is 22,000 light-years away. Light would need over a century to traverse its diameter.
M3 is a globular cluster with a half of a million stars. It orbits the core of our Milky Way Galaxy almost perpendicular to the galactic disk. It is currently 33,900 light-years away, and approaching our Solar System at 100 miles per second.
M35 is an open star cluster of over 300 stars. It lies at a distance of 2,800 light-years from Earth, near the foot of Castor, one of the Gemini twins. Tiny nearby cluster NGC 2158 is in the same field of view.
M44 The Beehive
M44, the “Beehive Cluster,” and also known as “Praesepe,” is a large, bright, diffuse open star cluster containing about 400 stars. It lies fairly close, at a distance of under 600 light-years.
NGC 3242 (Ghost of Jupiter)
Mizar & Alcor
In the handle of the Big Dipper, Mizar & Alcor (ζ & 80 Ursae Majoris) or the “Horse & Rider” form a naked-eye double star. They are traveling through space together about 80 light-years away from us, separated by about a light-year. However, it is unknown if they are actually gravitationally bound to each other. A telescope splits Mizar itself into two stars, but these both are again doubles, bringing the total in this system to six.
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Nightly Observing Program. Most of the above images were taken as
the Overnight Telescope Observing Program. For more information on this unique experience please visit Overnight Telescope Observing Program.
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