January 24 – January 31
The most inconspicuous of the zodiac constellations is faint Cancer the Crab, which is nestled between Gemini and Leo. In mythology, the crab was sent by the goddess queen Hera to distract Hercules while he was battling the Hydra. The crab was no match for the strongman’s stomp. Ancient Egyptians saw it as their sacred dung beetle, the scarab. In the first millennium BCE the Sun was in Cancer at the summer solstice, the time when it halts its northward motion and slowly starts heading south. This back and forth motion of the rising and setting Sun on the horizon was perhaps reminiscent of a crab sidling on a beach. The summer Sun is now situated in Taurus near the constellation border with Gemini.
Cancer is recognized by a trapezoid of dim naked eye stars as the crab’s body, with a couple of other stars representing the claws. The four stars were also seen as a manger flanked by a pair of donkeys, Asellus Borealis and Asellus Australis. On a clear dark night we can see a hazy patch of hay within the manger, and binoculars reveal it as a beautiful star cluster called the Beehive, Praesepe or M44. Being near the ecliptic, the planets often pass through or near this cluster, masquerading as a bright guest star. The Beehive was once used to forecast storms, for if it could not be seen it was hidden by light clouds at the front of a weather system. Binoculars can reveal another star cluster, number 67 on the Messier list of fuzzy non-comets, less than a fist-width south of M44.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 7:50 and sunset will occur at 5:12, giving 9 hours, 22 minutes of daylight (7:52 and 5:20 in Saint John). Next Saturday the Sun will rise at 7:42 and set at 5:22, giving 9 hours, 40 minutes of daylight (7:45 and 5:30 in Saint John).
The Moon is at first quarter on Monday, close to the Pleiades Tuesday and above Jupiter next Friday. Saturn is in the southwest after evening twilight this weekend, setting before 10 pm. Jupiter is at about the same altitude in the east at that time among the stars of Gemini. On Monday at 9:04 pm telescope users might see Jupiter’s moon Callisto reappear from transiting the planet at the same time that its shadow begins a transit on the other side, with the Red Spot midway across the planet. Venus, Mars and Mercury are out of sight on the far side if the Sun.
Tune in to the Sunday Night Astronomy Show at 8 pm on the YouTube channel and Facebook page of Astronomy by the Bay. Questions? Contact Curt Nason at [email protected].
January 17 – January 24
Monoceros is a constellation that is easy to locate, sandwiched between Orion’s dogs Canis Major and Canis Minor, but it is not easy to see. From urban areas its dim stars are as elusive as the unicorn they depict. It was one of eight new constellations created on a globe by the Dutch cartographer Petrus Plancius around 1612. Of those eight, only Monoceros and Camelopardalis are recognized as official constellations today. Monoceros is situated within the winter Milky Way, which is apparent in rural skies.
Despite being a dim constellation, Monoceros is home to some favourite targets of astrophotographers, in particular the beautiful Rosette Nebula. Another is the combination of the Cone Nebula, Christmas Tree Cluster and the Fox Fur Nebula. Check the Internet for their stunning images. Monoceros has one Messier object within its boundary, the large open cluster M50, otherwise known as the Heart-Shaped Cluster. It can be seen in binoculars about 40% of the distance from Sirius to Procyon. Three other open clusters on the Messier list are found near Monoceros but they lie officially within other constellations. They are the close pair of M46 and M47 in Puppis, and M48 in Hydra.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 7:56 and sunset will occur at 5:02, giving 9 hours, 6 minutes of daylight (7:58 and 5:10 in Saint John). Next Saturday the Sun will rise at 7:50 and set at 5:12, giving 9 hours, 22 minutes of daylight (7:52 and 5:20 in Saint John).
The Moon is new on Sunday and it passes above Saturn next Friday. Saturn is fairly high in the southwest in early evening, setting around 10 pm. Jupiter is at its highest by 11:30. On Wednesday telescope users might see Jupiter’s moon Io lead its shadow across the planet between 7:50 and 10:20, at which time the Red Spot will be midway across the planet. Venus, Mars and Mercury are out of sight, with Mercury at superior conjunction on Wednesday.
Tune in to the Sunday Night Astronomy Show at 8 pm on the YouTube channel and Facebook page of Astronomy by the Bay.
Questions? Contact Curt Nason at [email protected].