Sagittarius - Constellation of the Month
Image Adapted by Celestial Events SA from Stellarium
Sagittarius is most easily identified by the asterism, ‘The Teapot’. The main body of the constellation looks like a traditional teapot when viewed from the correct angle. In terms of mythology, Sagittarius’s origins are unclear, but most accounts suggest that the celestial archer is Crotus, son of the god of the wild, Pan.
Crotus is often depicted as a Satyr, a mythological creature with the head and torso of a man on the body of a goat. Many charts however, (including this one) incorrectly show Pan as a Centaur….
Crotus is said to have invented the sport of archery and is often depicted aiming an arrow at Antares, the heart of the neighbouring Scorpius.
Despite the lack of mythology, Sagittarius is packed full of fascinating objects due to its position in the Milky Way. When looking at Sagittarius, you are looking towards the centre of our galaxy, a super-massive black hole known as ‘Sagittarius A’.
Despite being a prominent constellation, Sagittarius lacks any iconic stars. The brightest star in the constellation is known as Kaus Australis which translates as ‘Southern Bow’, in relation to the mythology of Crotus, inventor of archery.
Kaus Australis is a main sequence star approximately 140 light years away and ranks as only the 36th brightest star in the sky.
DEEP SKY OBJECTS
Due to its position along the galactic plane, Sagittarius is chocked full of deep sky objects to explore, many of which are within reach of amateur equipment. It is home no less than 15 Messier objects!
Messier 8 - The Lagoon Nebula
Image Credit: ESO/VPHAS+ Team
One of only 2 areas of star formation visible to the naked eye along with Messier 42 in Orion. M8 is over 4000 light years away and the nebulosity surrounding the area is illuminated by a group of young stars recently created in its centre. Despite its distance, M8 can be spotted with the naked eye and a great target for basic astrophotography!
Messier 20 - The Triffid Nebula
The Trifid Nebula is a beautiful mix of an emission nebula and a reflection nebula and these 2 areas manifest themselves with a stunning dichotomy of colours in long exposure images. Like M8, M20 is also illuminated by a cluster of recently formed stars in its centre that is considered to be among the youngest known – only a few thousand years old. The Trifid Nebula gets its name from the lobed appearance caused by dark dust lines running within it.
Messier 24 - The Sagittarius Star Field
M24 is unusual in that it is one of only 3 Messier entries that do not refer to a specific ‘object’. The Sagittarius Starfield is a true window to the galaxy as it shows an uninterrupted view of the arms of the Milky Way. In fact, seen through binoculars, this area of sky contains the most stars one can see in a single field of view (more than 1000!)