Sagittarius, 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)
Scorpius is perhaps the most beautiful of the zodiacal constellations. This southern constellation is located on the ecliptic between Libra and Sagittarius and is situated south of Ophiuchus. Antares (Alpha Scorpii), the reddish 1st magnitude star might first catch the observers attention. Then look for the remainder of the constellation which includes a distinct head, long slender body, curling tail, and stinger of a scorpion. Even though Sagittarius is on the lowest point of the ecliptic, Scorpius is the southernmost of the zodiacal constellations, which tends to leave the tail hanging below the treeline for us northern latitude observers. Southbound travelers in July, which is when Scorpius reaches its highest nightfall ascension, should make it a point to observe this very pretty constellation.
Scorpius’ location on the Milky way makes it home for many deep sky objects, such as the Butterfly Cluster (M6) and the Ptolemy Cluster (M7). Other objects cataloged by Charles Messier include globular clusters M4 and M80. http://en.wikipedia.org/wiki/Scorpius
Leo, the lion, is a distinctive zodiacal constellation that was cataloged by 2nd century astronomer Ptolemy. It is located on the ecliptic between Cancer and Virgo, and can be found below the bowl of the Big Dipper with both constellations arriving at their highest nightfall ascension in April. Leo closely resembles a crouching lion with its rather distinct backward question mark, or sickle asterism. This constellation features the bright star Regulus (Alpha Leonis) at the back of the lion’s head.
The most famous deep sky object in Leo is The Leo Triplet is a close grouping of the galaxies M65, M66 (displayed) and NGC3628 that can be seen together in a single telescopic field of view. For those observing with telescopes, there are several other galaxies cataloged by Charles Messier are located in Leo, to include M65, M66, M95, M96 and M105. Leo is also home to the famous Leonids meteor shower that occurs during November, peaking at about 10 meteors per hour on November 14th and 15th. http://en.wikipedia.org/wiki/Leo_(constellation)
While Deep Space Objects (DSOs) technically includes stars, it is generally about nebulae, galaxies, and star clusters. Most are small and dim, so a telescope is needed to see them. Others can be seen with modest magnification of binoculars or a small telescope. Initially I will limit this newsletter to those visible with the unaided eye, and eventually cover those that can be seen with some magnification. It is important to note that DSOs never appear as bright and colorful to the eye, even when using a amateur telescope, as they do in astrophotographs. This is because camera film (in days past) or sensors can gather light over much longer periods of time than can the human eye. Many of the brighter and more interesting DSOs were cataloged by Charles Messier in the 18th century. Messier objects are assigned an ‘M’ number.