In this first instalment of 2016, we present an overview of the most noteworthy astronomical events to watch for over the coming twelve months.
Eclipses, transit and occultations
There are no eclipses in Quebec this year! Neither of the two solar eclipses taking place in 2016—one total, the other annular—will be visible from North America. Three unspectacular penumbral lunar eclipses will also take place. However, only that of March 23 will be visible, in principal, from Quebec; it begins at dawn just as the Moon is setting over our region, which will render it imperceptible.
On the other hand, we’ll have a chance to observe “eclipses” of another kind this year. Mercury will pass directly in front of the Sun for a few hours on May 9: This rare event, technically known as a transit, will be visible in its entirety from eastern North America. In Montreal, the tiny planet will begin moving in front of the solar disk at 7:13 A.M. and will slowly cross the Sun throughout the morning and early afternoon, egressing completely at 2:41 P.M. A word of caution! Since this event involves observing the Sun through a telescope, it is extremely important to take measures to protect your eyes: telescopes must be fitted with solar filters specifically designed for this purpose.
As well, the current series of occultations of the star, Aldebaran, continues in 2016. These are, in fact, “stellar eclipses” that occur when the lunar disk passes in front of a star other than the Sun. Since the Moon travels at about one kilometer per second in its orbit around Earth, the disappearance and reappearance of occulted stars happens relatively quickly. In the case of bright stars like Aldebaran, in the constellation Taurus, the event is visible to the naked eye, but binoculars or a small telescope will help to anticipate exactly when the star will vanish behind the lunar limb. The first of the occultations for 2016 takes place on the evening of January 19: Seen from Montreal, Aldebaran will disappear behind the waxing gibbous moon around 9:27 and will reappear on the other side about 10:43 P.M. But the exact timing is very sensitive to the observer’s precise geographical location; so to avoid missing the event, be prepared observe it a few minutes in advance. Three more occultations of Aldebaran will be visible from Quebec before the end of the year: one is underway at twilight on April 10, another occurs early in the evening on October 19, and the last one is during the night of December 12 to 13.
In 2016, two of the principal annual meteor showers will take place under favourable circumstances. The year begins in full swing with the Quadrantids, which reach their maximum early on January 4: This is often one of the strongest annual showers, though its maximum only lasts a few hours. Observe it, well bundled against the cold, before 2:00 A.M. when the waning Moon rises and affects visibility. The Quadrantids get their name from a defunct constellation that’s no longer recognised today: The radiant is in the northern part of Boötes, near the border of Draco, and rises during the latter half of the night.
The Eta Aquarids reach their maximum on May 5, however, this average intensity shower peaks over several days. The radiant is situated in Aquarius: Since it rises after 3:00 A.M., this shower is best viewed during the pre-dawn hours. The Moon will be new and not affect observations. When you see these meteors, remember… they are actually particles of Halley’s comet burning up in the atmosphere.
Though average, the renowned Perseids are expected to put on a good show this year, when they reach their traditional peak on the morning of August 12. But some computer models show the Earth going right through the trail of dust laid down by comet 109P/Swift-Tuttle when it passed by our planet in 1737: This should occur between 8:00 P.M. and midnight on August 11 (EDT), so European observers will have the best seats. In any case, the Moon will reach first quarter on the August10and will set just after midnight the following evening of the 11th to 12th. Conditions will be favourable for observing the Perseids, when the radiant is highest in the sky, during the latter part of the night until dawn.
Regarding the planets
Mercury is easily visible in the evening sky during the first days of January. Look for the tiny planet in the twilight, above the southwest horizon. But this situation is short-lived: Mercury’s brightness diminishes quickly and it disappears from view around January 7. There will be two more excellent windows of observation for the closest planet to the Sun: in the evening sky from March 31 to April 20, and at dawn from September 21 to mid-October.
Altogether, this will not be a good year for observing Venus. However, 2016 begins well for the brightest planet of them all: It dominates the morning sky in January and is impossible to miss in the southeast at dawn. On the morning of January 9, Saturn and Venus shine together just one third-of-a-degree apart—close enough to both appear in the same telescopic field of view! But the dazzling planet’s visibility deteriorates rapidly as it approaches the horizon, and the Sun. After mid-February, Venus is less than 5 degrees above the east-southeast horizon at dawn, half-an-hour before sunrise, and becomes increasingly harder to see: It finally vanishes in the dawn twilight in April. The brilliant planet gradually reappears in the July evening sky, but remains close to the horizon, in the twilight, until October. Venus finally gains altitude only toward the end of the year: In December, it appears about twenty degrees up, in the south-southwest, 30 minutes after sunset.
As the year begins, Jupiter is well placed for observation, high in the mid-night sky, just below the main asterism of Leo. The giant planet is at opposition on March 8: Observe it with the naked eye, moving westward among the stars, as it undertakes its retrograde loop from January 8 to May 9. On the evening of August 27, right after sunset, scan the western horizon and you’ll find Venus and Jupiter a scant 5 arc minutes apart! This conjunction between the two brightest planets, will be the most spectacular of the year, but it takes place quite close to the horizon. Jupiter will vanish in the twilight over the following evenings and, after passing behind the Sun, it will reappear in October at dawn. The gaseous giant will be easy to see during the latter half of the night toward the end of the year.
Mars will be, without doubt, the planetary “star” of 2016, as it comes closer to Earth than it has over the past ten years. However, during the few weeks surrounding its opposition on May 22, the Red Planet will be in a region of sky that remains low on the horizon for northern hemisphere observers, which will hamper telescopic observations. At the beginning of the year, Mars is still relatively faint to the naked eye: It can be found during the pre-dawn hours in the east-southeast, not far from the bright star, Spica. But it rapidly grows brighter throughout the winter and spring: from April 30 to June 28, the Red Planet will even surpass Sirius, the brightest star in the sky! Pay close attention to Mars’ movement among the constellations: Starting on April 17, the planet begins its retrograde motion, toward the west, until June 29 when it resumes its regular eastward course. In conclusion, this spring and summer Mars will describe a large figure “S” against the stars of Ophiuchus, Scorpius and Libra.
Saturn has its turn at opposition on June 3. The ringed planet is currently in Ophiuchus, a few degrees north of Antares and the Scorpion’s head, where it will undergo its retrograde loop from March 25 to August 13. This is the same region of sky that Mars occupies, and like the Red Planet, Saturn won’t rise very high in Quebec skies, which also hinders telescopic observations. But its rings are well inclined and appear tilted about 26 degrees. Before mid-April, Saturn is only visible during the latter part of the night; following that it will be visible in the evening sky throughout summer and until November.
Happy 2016… and clear skies to all!