Tag Archives: Draco

Draco (The dragon)

Draco, Ursa MinorDraco is a large constellation of rather dim stars that is also one of the 48 constellations cataloged by 2nd century astronomer Ptolemy. Since it is a circumpolar constellation at 40 degrees north latitude, it is visible on any night at any time, but it reaches its highest nightfall ascension in January. Draco’s tail starts near the northernmost pointer star of the Big Dipper, and it roughly parallels the curvature of the Big Dipper handle before curving under the Little Dipper and turning back toward the south, and then terminating at the dragon’s head. The best chance of seeing this constellation will be under a very dark sky.

Thuban (Alpha Draconis), is the most interesting star in Draco. Six thousand years ago, when the Egyptian pyramids were build, Thuban was the Earth’s pole, or north star, and the Egyptians built north-facing entrances on the pyramids that were aligned to this star. Due to precession, the large circle that the Earth’s axis traces among the fixed stars every 26,000 years, Polaris has temporarily supplanted Thuban as the pole star. The most notable deep sky object in this constellation is the Cat’s Eye Nebula (NGC 4563).
http://en.wikipedia.org/wiki/Draco_(constellation)

IAU Draco Chart, IAU and Sky $ Telescope (Roger Sinnott and Rick Fienberg), June 5, 2011.
IAU Draco chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

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

Cygnus (The swan)

Cygnus, LyraCygnus, the swan, is a bright and distinct northern constellations, and one of the 48 constellations cataloged by 2nd century astronomer Ptolemy.  It is located among Lyra, Hercules, Draco, Cepheus, Lacerta and Pegasus. Deneb (Alpha Cygni) is its brightest star, and a member of the Summer Triangle. Cygnus reaches its highest ascension in September. A gracefully flying swan can be  easily imagined while taking in this constellation. Cygnus is also known as the Northern Cross.

Cygnus lies on the Milky Way’s plane, and is thus filled with many deep space objects. Of these, two were cataloged by Charles Messier. M39 is an open cluster of about 30 stars in the north east corner of Cygnus, and M29 is a small open cluster near the crux of the Northern Cross. There are several named nebula, star clusters, and galaxies to include the Blinking Nebula (NGC 6826), the Rocking Horse cluster (NGC 6910), the Veil Nebula, the North America Nebula (NGC 7000), the Northern Coalsack nebula, the Soap Bubble nebula (PN G75.5+1.7), and the Fireworks galaxy.
http://en.wikipedia.org/wiki/Cygnus_(constellation)

IAU Cygnus chart, (IAU and Sky & Telescope magazine (Rober Sinnott & Rick Fienberg), June 5, 2011.
IAU Cygnus chart, (IAU and Sky & Telescope magazine (Rober Sinnott & 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