Stars over Sisters

As we move into the month of March there are new objects to focus on in the night sky.

Out of the many constellations that can be seen, the one to look out for is Pyxis, the constellation referred to as the Mariner's Compass. It is surrounded by the constellations Puppis, Hydra, Vela, and Antlia, and is best seen in the evening at around nine o'clock in the southern sky.

Pyxis is made up of three main stars; Alpha Pyxidis, Beta Pyxidis, and Gamma Pyxidis. The Alpha star is a large star, being ten times the mass and six times the radius of the Sun. It is predicted that Alpha Pyxidis will explode in a supernova because of it's size. Beta Pyxidis is a yellow-white giant which is an estimated twenty-five times larger than the sun. It is the beta star not because of it's size, but because from Earth it appears to be dimmer than Alpha Pyxidis.

Finally, Gamma Pyxidis is a giant yellow-orange star that is similar to the Sun, but is three times larger.

All three of these main stars have orbiting planets which have been discovered through the process of Doppler Spectrocity which uses the wavelengths of light to prove that there is an object orbiting the star.

Pyxis is said to be a part of the former constellation known as Argo Navis, which was eventually split into three main constellations: Carina, Vela, and Puppis.

Argo Navis was a ship in Greek Mythology, and each of the three split constellations represents a part of the ship.

Pyxis is a subordinate detachment of Argo Navis because it is in very close proximity to the actual divisions of the constellation, but is not considered an actual division itself.

Pyxis doesn't contain any Messier objects but it has several deepsky objects, one being NGC 2818, a planetary nebula. What is special about NGC 2818 is that it is located within an open cluster called NGC 2818A. There are only a handful of nebulae that exist within a cluster. This is because the open cluster disperses faster than its stars can age to the point of forming a planetary nebula. NGC 2818 was formed by a sun-like star that ran out of fuel to sustain itself. Therefore, over the next tens of thousands of years the core will be left as a white dwarf, which will remain there for millions of years. Our own star will eventually go through this process in the very distant future.

Another object to look for this month is 41P/Tuttle-Giacobini-Kresák, a comet first discovered in 1858 by Horace Parnell Tuttle, rediscovered in 1907 by Michel Giacobini, and in 1951 by L'ubor Kresák. The comet will be closest to the Earth in late March, being only 13.67 million miles away, the closest this comet has been to the Earth in the last century. It can be seen best with binoculars, but can also be visible to the naked eye.

This month, Venus will appear in the western skies along with Mars. Jupiter will be visible in the South East. The full moon will appear on March 11, and will start waning until March 27, when the new moon begins. Finally, mark your calendars for March 20, when the spring equinox starts off the new season.