Tag Archives: August

Scutum (The shield)

Scutum, SagittariusOriginally named Scutum Sobiescianum (Shield of Sobieski) to commemorate the victory of Christian forces led by Polish King John III Sobieski in the Battle of Vienna in 1683, the name was later shortened to Scutum. This is a small, dim constellation located between the tail of Aquila, above the head of Sagittarius, and to the left of Ophiuchus. Scutum reaches its highest nightfall ascension in August. It contains two Messier star clusters, M11 (the Wild Duck Cluster), and M26 (NGC 6694).
http://en.wikipedia.org/wiki/Scutum

609px-Scutum_IAU.svg
IAU Scutum chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

 

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

Perseus (A Greek mythological hero)

PerseusCCThe constellation Perseus is located near several other constellations to which Perseus is related in Greek mythology: Cepheus, Andromeda, Pegasus, Cassiopeia, and Cetus. This constellation was one of the 48 constellations cataloged by 2nd century astronomer Ptolemy that remain among the 88 modern constellations. This easily spotted constellation is well placed high in the northern sky and best seen in January. It is found between Cassiopeia and the Pleiades, and Mirfak (Alpha Persei) is its brightest star Its most interesting star Algol (Beta Persei) is an eclipsing binary star. Its variable brightness, which is noticeable to the naked eye, decreases by over one degree of magnitude for about ten hours on a cycle time of just under three days. This star is also known as the Demon Star, because the ancients perceived its variability as an ominous sign. Also notable in this constellation is theNGC869NGC884 Double Cluster (NGC 869 and NGC 884), which are naked eye objects under very dark skies. Perseus is home to two Messier objects, M34 and M76, and to the Perseids meteor shower. This meteor shower, one of the most consistently prominent meteor showers each year, lasts from mid-July to late August, peaking between the 9th and 10th of August.
http://en.wikipedia.org/wiki/Perseus_(constellation)

606px-Perseus_IAU.svg
IAU Perseus chart, IAU and Sky & Telescope magazine (Roger Sinnott and Rick Fienberg), June 5, 2011.

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

Sagittarius (The archer)

Constellation SagittariusSagittarius, the archer, is a zodiacal constellation that is rather easily found because of its distinctive teapot asterism. It is one of the 48 constellations cataloged by the 2nd century astronomer Ptolemy. It is located on the ecliptic between Scorpius and Capricornus. It can also be found by starting at Altair (a Summer Triangle star) and tracing southward along Aquila’s long axis. As is situated on southern most point of the ecliptic, this constellation hangs low in the southern sky, reaching its highest nightfall ascension in August. The Sun’s arrival at the southernmost point of the ecliptic around December 21st marks Winter Solstice and the first day of Winter.

This constellation has the distinction of presenting the foreground stars in the direction of the dense center of the Milky Way galaxy, which is rich in Messier objects. As such, it is worth taking the time to scan this constellation with binoculars or a small telescope. Several well-known nebula can be found in Sagittarius to include the Lagoon Nebula (M8), the Horseshoe Nebula, the Omega Nebula (M17), the Trifid Nebula (M20), and the Small Sagittarius Star Cloud (M24). Other Messier objects include M18, M22, M23, M25, M28, M54, M55, M69, M70 and M75.
http://en.wikipedia.org/wiki/Sagittarius_(constellation)

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

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