Bushwise Field Guides

As the winter temperatures drop, the clarity of our night sky continues to increase. The lack of water vapour in the air means less atmospheric distortion and the stars are shining like beacons across the sky. For the amateur astronomer, the next few months hold some great sights to try and pick out. Here are our top objects to keep an eye out for:

1. Saturn
Saturn is without doubt the most impressive object to view in the night sky. Many a person has been converted to the field of astronomy after catching a glimpse of the gas giant and its spectacular rings. Even though it is in excess of 1 billion kilometers away, the rings of Saturn are visible through even the most basic telescope. Due to a wobble on its axis, the orientation of the rings changes over a about a 15 year period and currently the rings are at their most visible, affording dramatic viewing of this jewel in the crown of the heavens. Look for a bright object beneath the prominent constellation of Scorpius!

2. Antares
Scorpius is one of the most recognizable constellations in the night sky (and one of the very few that actually resemble what they were named after!) Its brightest star is the red supergiant called Antares. This massive star dwarfs the Sun and should it replace our Sun, its diameter would extend well beyond the orbit of Mars! The name Antares is derived from the planet Mars. The Roman god of war (Mars) is known as ‘Ares’ in Greek and due to the two objects being reddish in colour, and passing close by each other, Antares is considered to the be the ‘Rival of Ares’, hence ‘Antares’.

3. Ptolemy Cluster (M7)
The Ptolemy Cluster is an open cluster of around 80 stars that were all created from the same dust cloud and are thus gravitationally bound and related, travelling through the abyss of space as a group. Easily visible with the naked eye, M7 can be found below the ‘stinger’ of Scorpius’s tail. It was first recorded in 2AD by Ptolemy, who was one of the first proponents of the Geocentric Theory of the heavens which held that the Earth was centre of the universe. It was only in the 17th Century that observations of Galileo finally debunked this now redundant idea.

4. Sagittarius
Nestled below Scorpius is the constellation of Sagittarius. Its main stars are known as an asterism called ‘The Teapot’ due to their positioning and is the easiest way to locate the constellation. Sagittarius crosses the plane of the Milky Way and is thus packed full of deep sky objects and star fields. When one looks at the Milky Way behind Sagittarius, one is actually looking at the centre of our galaxy and what is considered to be a super-massive black hole!

5. The Lagoon Nebula (M8)
The Lagoon Nebula is situated close to Sagittarius and can be found by looking above the ‘spout’ of the teapot (mentioned above). It is one of only a few star forming regions visible with the naked eye, the most famous being the Orion Nebula found in the ‘sword’ of Orion. Within the nebula, dust is collapsing and as these clumps grow, they will eventually create enough gravity to spark nuclear fusion and so new stars are created.

6. Corvus
Corvus is high in the night sky at present and is easily identifiable as a bright square of stars close to Virgo. In mythology, Corvus represents a crow that was sent by Apollo to fetch some water from a sacred spring. The crow however was distracted by a ripe fig tree and failed to return with the water until a few days later. In order to explain his tardiness, the crow claimed that he was unable to reach the water due to the presence of a giant water snake. Apollo saw through this deception and as punishment, placed the crow (Corvus), a cup of water (Crater) and the water snake (Hydra) in the sky together. Hydra now guards the cup of water so that the crow is destined to be thirsty forever, explaining the crow’s harsh call that we all know so well.

7. The Carina Nebula
The Carina Nebula envelops the binary star Eta Carina in the constellation of the same name. Visible through binoculars as a faint fuzzy patch of sky, the nebula contains over 8 open clusters but such is the radiation and stellar winds being produced by all this star formation, the dust responsible for future star formation will be lost in the next hundred thousand years leaving only the clusters behind.

8. Vega
If one looks to the eastern horizon, the famous star known as Vega is beginning to rise. Vega is the brightest star in the constellation of Lyra and is the 5th brightest star in the sky. It is well known for being the first star that was imaged after the Sun and is thus the benchmark against which all other stars are compared to in terms of brightness and colour. Due to the Earth’s axial wobble (known as ‘Precession’), Vega was the north star 14,000 years ago and will be so again in another 11,000 years or so!

Happy star gazing!!

Blog by Ben Coley