This Week’s Sky at a Glance, May 20 – 27 ~by Curt Nason
A favourite galaxy among stargazers is M104, number 104 in the 18th century Messier catalogue of fuzzy objects that could fool a comet hunter. This object is better known as the Sombrero Galaxy as it resembles such a bonnet in astrophotos, thanks to a central dust cloud that forms the brim. The dust cloud can be seen from a rural location with a medium-size amateur telescope. The galaxy is seen as a small gray smudge with binoculars.
Although M104 is officially within the borders of the constellation Virgo, most people start their search from the recognizable quadrilateral of stars that forms Corvus the Crow. In mythology, Corvus was sent by Apollo to fetch a cup of water from the river but the bird was distracted by ripening figs. When the crow returned late it made up a tale that it had been deterred by a water snake (Hydra). In a fit of rage, Apollo tossed the bird, the cup and the snake into the sky. To the right of Corvus is the constellation Crater the Cup, and they both sit atop Hydra. They can be seen in the southern sky when twilight fades to darkness.
To find M104, imagine a line from the middle of the bottom of Corvus to the upper left star, and extend it not quite that distance. Look in this area for a small arrowhead of three or four stars. This asterism has been called the Stargate. The arrowhead points to a small line of a few stars, which in turn points toward M104 nearby. That line of stars also forms the mouth of an asterism called the Shark, which has a fin and a curved body stretching away from the Stargate. Good luck, and wear your Sombrero proudly.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 5:41 am and sunset will occur at 8:51 pm, giving 15 hours, 10 minutes of daylight (5:48 am and 8:53 pm in Saint John). Next Saturday the Sun will rise at 5:34 am and set at 8:58 pm, giving 15 hours, 24 minutes of daylight (5:42 am and 9:00 pm in Saint John).
The waning crescent Moon lies 2 degrees below Venus around 10 am Monday, providing an opportunity to see Venus in daylight. Locate them first with binoculars and then try to see Venus with just your eyes. The Moon is new and at perigee on Thursday, so we can expect to see extreme tides into next weekend. Jupiter is highest in the sky and at its best soon after twilight, while Mars is dimming and sets at 10:30 pm. Saturn is well placed for observing during the wee hours. Mercury is brightening as it heads sunward but you will need to rise with the birds and use binoculars to see it in the dawn twilight.
Questions? Contact Curt Nason.