Sagittarius, the Archer

Sgr

Sagittarii

Sky Chart and Artist Rendering of Sagittarius

Origin:
Sagittarius is a prominent and old zodiacal constellation (ninth in the ancient zodiac) dating back to the time of the Assyrians and Babylonians.  On ancient drawings and maps, Sagittarius is drawn as a Centaur -- half man, half horse -- with a bow in one hand and the arrow pointed at Antares, the Heart of Scorpius, the Scorpion.

Information:
Sagittarius is the ninth constellation of the ancient zodiac and a summer constellation in the northern hemisphere. The Archer culminates in the south at 9 pm on August 25.  The primary asterism of Sagittarius is described by most to look like a "teapot."  The spout of the teapot (the shoulder of the Archer) points into the Sagittarius Star Cloud and, were we able to see through the 1000's of light years of interstellar dust, we would see the core of the Milky Way Galaxy 26,000 light years away.  With the Milky Way running right through Sagittarius, the constellation is a treasure-trove of stars, asterisms, and deep sky objects.  With the naked-eye or binoculars, many star clusters appears as bright spots.  With a telescope, one could in a single evening see 14 of the 110 objects in the Messier Catalog, including 8 globular clusters, 5 open clusters, and at least 5 emission or dark nebulae.  Sagittarius is home to two or three of among the most famous nebulae: Lagoon Nebula (M8), Omega (or Horseshoe or Swan) Nebula (M17), and Trifid Nebula (M20).  All three nebulae are excellent deep sky objects for telescopes with apertures larger than 60 mm (2.5").

Off in the northeastern boundary of the constellation is NGC 6822, which is an irregular companion galaxy about 1.7 million light years from the Milky Way Galaxy and is considered a member of the Local Group.  Known as Bernard's Dwarf Galaxy, it is similar to but smaller than the Small Magellanic Cloud that is best viewed in tripod-mounted binoculars at less than 20 power or through a telescope with a rich-field eyepiece. Photographically, Bernard's Dwarf Galaxy shows up as a condensation of stars more dense than the surrounding Milky Way stars.

Mythology:
This centaurs are often-used creatures in Greek mythology. They were usually rude, deceptive, violent,  dishonest, and generally unfriendly -- and they drank too much.  However, the centaur named Chiron was different.  Chiron was educated by the Apollo (god of the Sun) and Diana (goddess of the Moon and Wild Animals) to be kind, gentle, and wise.  Chiron's wisdom and learning were so famous that the children of the richest nobles were sent to his wilderness cave to learn from him.  Among his most famous students were Hercules, Jason (who would later recover the Golden Fleece), Aesculapius (who became a highly regarded and skilled physician), and Achilles. Beyond his learning, Chiron was also an excellent archer, musician, and physician.

In one legend Hercules, thirsty after a long day of traveling, asked a friend to open a jar of the fine wine kept in his house but belonged to the centaurs. (One has to question why someone would keep the wine of the generally disagreeable centaurs.) Contrary to his better judgment, the friend opened the jar and the fragrance of this exceptional wine wafted out over the countryside, attracting the attention of the rightful owners of the wine. The centaurs demanded to know why he would dare open the wine without their permission.  Not waiting for an answer, the centaurs became violently aggressive towards Hercules and his friend. Had they known who they were attacking, the centaurs may not have made such a dreadful mistake, for in no time at all Hercules had dispatched many of the centaurs and those not dead or dieing ran in terror from the countryside, never to return. Nearby, Chiron observed his former student deal with the centaurs, although he took no part in the melee. Hercules did not recognize his good friend and mentor from such a great distance and accidentally shot and wounded him with one of his arrows dipped in the poison of the Hydra. The pain and suffering that Chiron underwent was so great that, skillful physician though he was, he could not even cure himself. Being immortal, Chiron was destined to eternal suffering.

Long before this, the gods had cast Prometheus into Tartarus and chained him to a rock as a punishment for giving fire to man.  In Tartarus, Prometheus was tortured each day an eagle.  At the request of Hercules, Zeus agreed to release Prometheus if a substitute could be found who would willing take Prometheus' place. 

Chiron gave up his immortality and descended to Tartarus, thereby releasing Prometheus, and suffering less there than the eternal pain as an immortal centaur.  Seeing that this weighed deeply upon his son Hercules, Zeus placed the only good centaur ever among the stars as the constellation Sagittarius, the Archer.