This Week’s Sky at a Glance, 2019 March 30 – April 6 ~by Curt Nason
The spring star is springing up in the east these evenings. Arcturus is the fourth, or third, brightest star in the sky and the second brightest we can see from New Brunswick. It is just a tad brighter than Vega, the summer star, which rises around 9:30 pm this weekend. The winter star, Sirius, sets after midnight and Capella, the autumn star, never sets in southern New Brunswick. The discrepancy over whether Arcturus is third or fourth brightest depends on how you define it. Alpha Centauri, in the southern hemisphere, appears brighter but it is a close double star – too close to split with the naked eye – and Arcturus is brighter than either but not both.
Arcturus anchors the constellation Boötes (bo-oh-teez) the Herdsman, and the star’s name means “bear driver.” Boötes is seen chasing the two bears, Ursa Major and Ursa Minor, around the celestial North Pole. To many people the constellation resembles a tie, a kite or an ice cream cone. The head of the herdsman, at the tip of the constellation opposite Arcturus, is the star Nekkar, which sounds somewhat like necktie.
Halfway between Arcturus and the hind leg of Ursa Major is the star Cor Coroli in Canes Venatici the Hunting Dogs. Use binoculars to look for a fuzzy patch halfway between Arcturus and Cor Coroli. This is a globular cluster called M3, the third entry in Charles Messier’s 18th century catalogue of things that resemble a comet but aren’t. This cluster contains half a million stars at a distance of 34,000 light years, nearly a thousand times farther than Arcturus.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 7:03 am and sunset will occur at 7:44 pm, giving 12 hours, 41minutes of daylight (7:08 am and 7:49 pm in Saint John). Next Saturday the Sun will rise at 6:50 am and set at 7:54 pm, giving 13 hours, 4 minutes of daylight (6:55 am and 7:58 pm in Saint John).
The waning crescent Moon is a few degrees below Venus, and nine degrees to the right of Mercury, in twilight on Tuesday, and it is new on Friday. Saturn is a hand span to the lower left of bright Jupiter, with the pair straddling the Teapot asterism of Sagittarius. Mercury rises 50 minutes before sunrise but due to its low altitude you will require binoculars and luck to see it. Mars slides between the Pleiades and Hyades star clusters in the evening sky this week. Use Mars and the Pleiades as a guide to view the zodiacal light angling up from the western horizon about an hour after sunset. You will need a clear, dark sky to see this phenomenon of sunlight reflecting off dust along the ecliptic.
The Saint John Astronomy Club meets in the Rockwood Park Interpretation Centre on April 6 at 7 pm. All are welcome.
Questions? Contact Curt Nason.