This Week’s Sky at a Glance, 2021 April 24 – 2021 May 1
~by Curt Nason
A favourite galaxy among stargazers is M104; 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 6:16 am and sunset will occur at 8:18 pm, giving 14 hours, 2 minutes of daylight (6:23 am and 8:21 pm in Saint John). Next Saturday the Sun will rise at 6:05 am and set at 8:27 pm, giving 14 hours, 22 minutes of daylight (6:12 am and 8:30 pm in Saint John).
The Moon is full early Tuesday, less than 12 hours before perigee so expect higher tides for a few days into midweek. Mars passes about one Moon-width from the M35 star cluster on Tuesday, making a fine sight in binoculars or in a telescope at low power. Mercury is one degree to the right of Venus this Saturday, and it should be bright enough to be seen with binoculars 25 minutes after sunset. Uranus is just below them but unseen, heading toward conjunction with the Sun on Friday. By next weekend Mercury will be setting 80 minutes after sunset and half an hour after Venus. Jupiter rises at 4 am this weekend, 40 minutes after Saturn.
With astronomy meetings and outreach activities on hold, you can watch the local Sunday Night Astronomy Show at 8 pm and view archived shows.
Questions? Contact Curt Nason.