~ St. Maarten’s Backyard Astronomy for March 10 - 12 ~
Sun rises at 6:23am
Sun sets at 6:21pm
Lunar phase: 4th quarter, waning half moon
Moon sets at 8:55am
Moon rises at 10:07pm
This weekend, we continue to be fixated on Venus and Jupiter, hanging languidly in the western sky after sunset. These two are slowly leaving their moment of conjunction, which officially peaked last weekend, but they are still poised to impress for those who are observant of the stars, the planets, the moon and all the beauty of the night sky.
After Venus and Jupiter set, keep looking west to find the stars of the Winter Circle beginning to edge towards the horizon. These stars form what astronomers call an aphorism, which is a “star shape” outside of those considered to be constellations. In fact the Winter Circle, also known as the Winter Hexagon is made of six different constellations.
Let’s look at each constellation in the Winter Circle and identify the brightest stars in each, beginning with our old friend, Orion the Hunter. Orion is likely the most easily identified constellation in the entire sky by reason of his three-star belt. This weekend at our St. Maarten location, Orion will be oriented on his side, so as you look west, the three-star belt will be diagonal from upper left to lower right, and his head will be to the right.
Once you spot the short straight line of three medium-bright stars, you are on your way to finding many other points of interest. Orion’s foot is the star Rigel and sits on the Circle’s edge, while his shoulder is marked by the star Betelgeuse, more or less at the centre of the Circle. From Rigel (Orion’s foot), aim your eyes to the right to find the constellation Taurus the Bull.
A classic star-hop learning technique goes like this: Find Orion’s belt and follow the direction of the line until you arrive at a very bright star. One direction (this weekend, left) takes you to Sirius, which is the brightest true star in the entire night sky, and if you extend the belt-line the other way (this weekend, right), it takes you to Aldebaran, the eye of the Bull, a bright star with a slight orange colour. Keep going right about the same distance again and you will find one of the most beloved sights in the sky: the Pleiades star cluster. The Pleiades are a tiny cluster of stars shrouded in interstellar gas and dust. Technically part of Taurus, this is a newly forming galaxy, visible to the naked eye but enhanced with binoculars or a telescope.
Continuing on around our Winter Circle from Rigel to Aldebaran; we go next to Capella, the goat star in the constellation Auriga the Charioteer. This weekend, Capella is on the right edge of the Circle. Scanning the sky up and around the Circle you will find two near identical stars located close together – these are the two Twin Stars of the constellation Gemini. Near the top of the Circle is Procyon or Little Dog Star. Coming down the left side of the Winter Circle you find Sirius, which is the Big Dog, and dropping down brings you back to Rigel.
This weekend, the planet Mars sits directly between Capella and Betelgeuse so there is added incentive to spend some time star-gazing towards the western sky through the evening hours. The Winter Circle begins to set at 8:30pm and is completely down by 1:00am.