This Week’s Sky at a Glance, 2020 February 15 – 22
~by Curt Nason
Binoculars are great instruments for observing the brighter star clusters and nebulae in the night sky, and Orion is a great place for binocular treasures. Its most prominent naked eye feature is the angled line of three stars that make Orion’s Belt. This trio will fit easily within almost any binocular view. They are hot giant stars, with the one on the right, Mintaka, being a little dimmer than Alnitak on the left and Alnilam in between. Although they appear to be near each other, at a distance of 2000 light years Alnilam is nearly three times farther than the other two. Between Alnilam and Mintaka binoculars will show an S-shaped asterism, Orion’s S, which peaks above his belt.
Below the belt is a string of a few dimmer stars that makes Orion’s sword, one of which looks fuzzy to the eye. Binoculars reveal this to be the Orion Nebula or M42, a vast cloud of gas and dust where stars are forming. Just above the nebula is an asterism that resembles a person running or perhaps the figure in a WALK sign. Several double or multiple stars can be seen in this general area. Binoculars will also enhance star colours so check out Orion’s two brightest stars, blue-white Rigel and orange Betelgeuse. Defocussing your binoculars slightly will enhance the colours even more. Keep an eye on Betelgeuse over the next couple of months. It has dimmed considerably lately, dropping from the top ten in stellar brightness to about 25th. Will it continue to dim or will it regain its gleam?
This Week in the Solar System
Saturday’s sunrise in Moncton is at 7:22 am and sunset will occur at 5:44 pm, giving 10 hours, 22 minutes of daylight (7:26 am and 5:51 pm in Saint John). Next Saturday the Sun will rise at 7:11 am and set at 5:54 pm, giving 10 hours, 43 minutes of daylight (7:15 am and 6:01 pm in Saint John).
The Moon is at third quarter this Saturday and poses with three morning planets this week. On Tuesday, telescope users might catch it occulting, or passing in front of, Mars just before 9 am. It is then near Jupiter on Wednesday and Saturn Thursday. Mercury begins a ten-day evening plunge toward the Sun this weekend, while Venus continues to catch the eye moving in the opposite direction. If you are far from urban light pollution on a clear evening, look for the ghostly pyramid of zodiacal light along the western ecliptic starting an hour after sunset.
The provincial astronomy club, RASC NB, meets in the UNB Fredericton Forestry-Earth Sciences building this Saturday at 1 pm. On Monday, at the Brundage Point River Centre in Grand Bay-Westfield, there will be an astronomy presentation at 6 pm followed by public observing.
Questions? Contact Curt Nason.