Tag Archives: Ursa Major

Leo Minor (The lesser lion)

Leo, Leo MinorLeo Minor is a northern constellation that walks the sky below Ursa Major’s hind legs and above Leo’s mane. Ptolemy, the 2nd century astronomer that cataloged many of today’s modern constellations, noted that the region of Leo Minor was undefined, and it remained that way until Johannes Hevelius first depicted it in 1687. Lying just outside the circle that defines circumpolar objects, this constellation can be seen most of the night year ’round, and it reaches its highest nightfall ascension in April. There are no Messier objects in Leo Minor, but there are several NGC objects available to the determined amateur astronomer’s telescope.
http://en.wikipedia.org/wiki/Leo_Minor

IAU Leo Minor chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.
IAU Leo Minor chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Boötes (The herdsman or plowman)

BootesBoötes is a bright and distinct northern constellation that is one of the 48 constellations cataloged by 2nd century astronomer Ptolemy. It can be found by looking south of Draco, lying between Hercules and Ursa Major. It is also found by following the curve of the Big Dipper’s handle southward and away from the bowl to the bright star Arcturus. Sometimes the phrase “arc to Arcturus” is used to describe this approach to locating it. Boötes reaches its highest nightfall ascension in June. Arcturus is the fourth brightest star in the night sky, and Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye.

There are no Messier objects located in Boötes, but several NGC galaxies can be found with a telescope. The radiant of the Quadrantids meteor shower, which displays about 100 meteors per hour when it peaks over January 3rd and 4th, is located between Bootes’ head and the end of Ursa Major’s tail.
http://en.wikipedia.org/wiki/Bootes_(constellation)

IAU Bootes chart, IAU and Sky  Telescope magazine (Roger Sinnott and Rick fienberg), June 4, 2011.

IAU Bootes chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 4, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net

Ursa Major (The great bear)

Ursa MajorUrsa Major is a circumpolar constellation that was cataloged by 2nd century astronomer Ptolemy. The Big Dipper asterism is perhaps the most easily identifiable aspect of this constellation. As a circumpolar constellation at 40 degrees north latitude, it can be seen at any time on any clear night from a location with an unobstructed view of the northern horizon. In April, however, Ursa Major reaches its highest ascension at nightfall.

All seven stars comprising the Big Dipper were named by the ancients. The Big Dipper’s handle is the bear’s tail and the bowl is the bear’s hindquarter. Upon closer examination and in a darker sky, all of the constellations stars add to the dipper to form a distinct and complete bear. The two Big Dipper bowl stars opposite the handle are the pointer stars that guide the eye to Polaris, or the north star. Following the arc of the tail away from the bowl, a method sometimes referred to as “arc to Arcturus,” leads the observer to the star Arcturus in the constellation Bootes.  Starting at the end of the tail and moving around through the bottom of the dipper’s bowl, the are: Alkaid (Eta Ursae Majoris), Mizar (Zeta Ursae Majoris) and its naked eye binary companion star Alcor,  Alioth (Epsilon Ursae Majoris), Megrez (Delta Ursae Majoris), Phecda (Gamma Ursae Majoris), Merak (Beta Ursae Majoris), and Dubhe (Alpha Ursae Majoris) . Impress your friends by committing these stars’ names to memory and pointing them out on a late Spring evening when the dipper is high in the northern sky.

Ursa Major contains several Messier objects. A famous pair is M81, a nearly face-on spiral galaxy, and M82, a nearly edge-on galaxy, that gravitationally  interact with one another and can be see within a single field of view of a modest telescope. M101, 108 and 109 are three other Messier galaxies, and M97, a planetary nebula are also found in Ursa Major. One rather odd Messier object is M40, which is the only double star in the Messier catalog.
http://en.wikipedia.org/wiki/Ursa_Major_(constellation)

IAU Ursa Major chart, IAU and Sky & Telescope magazine (Roger Sinnott and Fick Fienberg), June 5, 2011.
IAU Ursa Major chart, IAU and Sky & Telescope magazine (Roger Sinnott and Fick Fienberg), June 5, 2011.

© James R. Johnson, 2014.
jim@jrjohnson.net