Constellation Profile - Circinus

We now move to the fourth smallest constellation in our night sky.  Circinus is another of Lacaille's regions he developed during his groundbreaking observing trip to South Africa.  It is representative of a compass, a technical drawing instrument used extensively throughout the enlightenment.  The constellation stretches from 56°S to 71°S thus out of range of telescopes from Calgary.  This should not deter you from checking it out on your next trip South to Mexico or Hawaii.  It is very easy to locate as it sits a mere few degrees East of Alpha Centauri.  Follow the line from Beta Centuari through Alpha Centauri to the stars representing the compass.  The map below will help.

Star-hop to Circinus

The compass served a fundamental role in mathematics, architecture and science.  It could be found in almost every scientific lab throughout the 17th century.  Lacaille desired to honour its role by placing it in the sky as a constellation.  The original picture from his planisphere is shown below.

Lacaille Circinus

Johann Bode included Circinus in his great atlas -- Uranographia and provided his own pictorial representation.

Uranographia Circinus

Unlike several of Lacaille's constellations, Circinus has some easy deep sky objects that can be seen by amateurs with their backyard telescopes.  NGC 5823 is a magnitude 8 open cluster that can be found in the very northernmost region of the constellation.  If you are trying to bag all the Caldwell objects, this is number 88.  You can find another open cluster, known as Pismis 20 in the same telescope field of view as Beta Circini.

If you are into planetary nebulae and a challenge you should check out NGC 5315 on the border between Circinus and Musca.  It sits a mere 45' from the open cluster Cromwell 277.  It may require a large aperture telescope, patience and high magnification with good transparency conditions.

If you would like to go hunting for galaxies, check out the Circinus Galaxy sitting just over 2° northeast of NGC 5315.  It is also recommended for large aperture users.

The following image is my version of the constellation to add to my collection.

Circinus

Unlike a lot of Lacaille's constellations, Circinus actually seems to take the shape of the object it is supposed to be representing.  Circinus also hosts an apparent meteor shower that peaks at the beginning of June.  The Alpha Circinids which was first and seemingly only noted in New Zealand in 1977.  Future studies have indicated they may appear again in 2033.