Stunning Stars, Venus Kisses Saturn, Maximum Mercury, a Full Snow Supermoon, and Zodiacal Light!
The Bright Stars of February
Even with the moon near full, the cold clear nights of February feature many bright stars you can pick out with your unaided eyes in the evening sky. Keep this list handy. They’ll be there for the next month or so. I’ve put their brightness rankings (3rd brightest in the night sky, 7th, etc.) in brackets.
Let’s start in the western half of the sky because those stars set first. Look directly northwest after dusk for Deneb (19th), the top star of the Summer Triangle. Deneb is a hot, bluish white star that marks the tail of Cygnus (the Swan). It sets at about 10:30 pm local time.
Next, turn fully around and look very high up the eastern sky. Bright yellowish Capella (6th) will be positioned near the zenith and orange-tinted Aldebaran (14th) will be positioned about three fist widths to the right of it. Capella is the brightest star in the large circular constellation of Auriga (“Oar-EYE-gah”) (the Charioteer), while Aldebaran is the baleful red eye of Taurus (the Bull), whose triangular face is tilted down to the left. Two fist diameters above Capella, you will find the white star Mirfak (35th) in Perseus (the Hero). The sky around Mirfak is a spectacular in binoculars.
When you face south, the well-known constellation of Orion (the Hunter) sits below, and a little bit to the left of, Aldebaran. Orion’s eastern (left-hand) shoulder is the old and bright, reddish star Betelgeuse (11th). His opposite foot is a bluish star of similar brightness named Rigel (7th). Rigel’s 862 light-year distance from Earth is actually almost twice as far as Betelgeuse’s 498 light-years — but it emits much more visible light.
Orion’s three-starred belt is a highlight of the winter sky. From east to west (lower left to upper right) the stars are Alnitak (30th), Alnilam (29th), and Mintaka (67th). The three stars are evenly spaced — almost exactly 1.3° (or about three moon diameters) apart. Orion’s other shoulder is marked by bluish white Bellatrix (26th), and his opposite foot is called Saiph (53rd).
To the upper left of Orion sits the zodiac constellation of Gemini (the Twins). Its brightest stars are yellowish Pollux (17th) and pale white Castor (23rd). Like many twins, it’s a challenge to remember which is which. Castor, the higher star, rises first, just as “C” precedes “P” in the alphabet.
The world’s brightest night-time star sits below Orion. Sirius (1st), also called the Dog Star because it resides in the constellation of Canis Major (the Large Dog), is a very hot, bluish-white star. It’s so bright because it is our neighbour — positioned “just up the street” at only 8.6 light-years away. Sirius has a reputation for twinkling vigorously with flashes of pure colour. This is because it sits fairly low in the sky for mid-latitude residents, and we see it shining through a thicker blanket of refracting air.
While Sirius marks the dog’s head (or his collar, depending on how you connect the dots), his rear foot is marked by a star named Adhara (22nd), which sits 1.2 fist diameters below Sirius. Adhara is a distant and incredibly luminous star located 405 light-years away. Sirius’ bright little sibling Procyon (8th) sits 25° (or 2.5 fist widths) to Sirius’ upper left, under Gemini, in the constellation of Canis Minor (the Little Dog). At 11 light-years, it’s another close neighbour.
Turning our attention to the east, the bright, white star Regulus (21st), which marks the heart of Leo (the Lion), will be obvious in the lower third of the sky in early evening, and higher later on. After 9 pm local time, the very bright, orange-tinted star Arcturus (4th) will rise in the eastern sky in Boötes (the Herdsman). Arcturus’ name means “guardian of the bear”, because it follows Ursa Major (the Big Bear) around the heavens.
Speaking of Ursa Major, its famous asterism, the Big Dipper, is composed of seven medium-bright stars, three of which are ranked in the top 40 brightest stars (Alioth, Dubhe, and Alkaid). Contrary to popular belief, modest Polaris the North Star, which marks the long tail of Ursa Minor (the Little Bear) and the top of the Little Dipper’s handle, ranks only 48th in brightness.
In February, most of them will reach their highest points, in the southern sky, before midnight — perfect to catch your eye through a south-facing window before bedtime. Good hunting!
The Moon and Planets
Tonight (Sunday) the moon will buzz the southern edge of the large open star cluster known as The Beehive (or Messier 44) in the constellation of Cancer (the Crab). The moon and the cluster will both fit within the field of view of binoculars or a low magnification telescope, but the moon’s brilliance will mostly overwhelm the clusters’ stars. The moon sweeps past or through that cluster frequently because the Beehive’s position is only a finger’s width north of the ecliptic, the great circle around the sky that most solar system objects’ orbits are parallel with.
The moon’s disk will continue to fill with light until Tuesday morning. At that time, the February full moon, known as the Snow Moon or Hunger Moon will occur among the stars of Leo (the Lion). Since the moon will reach its full phase about midway between Monday and Tuesday evening, to the casual eye it will appear full on both nights. But if you look closely at the moon on Monday night, you’ll be able to see that the craters in a narrow strip along the moon’s left (or western) edge will have shadows. On the following night, that textured strip will migrate to the moon’s opposite (eastern) edge because the moon has crossed the line connecting the sun and Earth.
Full moons always rise around sunset and set around sunrise, and the position of the ecliptic on winter nights causes February moons to climb very high in the night sky. In fact, the shadows generated in your backyard by the bright moonlight will match the shadows cast by the sun in early August. This full moon will occur only 7 hours after perigee, the point in the moon’s orbit when it is closest to Earth, making it the largest and brightest full moon, or supermoon, of 2019 and will generate high tides globally.
From Wednesday onward, the moon will wane and rise later as it crosses through the constellations of Leo and then Virgo (the Maiden). In the pre-dawn southeastern sky next Sunday, the moon will appear a palm’s width above the medium-bright star Zubelelgenubi in Libra (the Scales).
This week offers your best and easiest opportunity to see Mercury during 2019, if you live in the Northern Hemisphere. The elusive inner planet will speedily climb higher and away from the sun all week, allowing it to set while the sky is darker. Find a viewing spot where the western horizon is low and free of foreground obstructions. Once the sun has fully set, sweep the sky with binoculars — or your own sharp eyeballs — looking for a medium bright, unmoving point of light. Early this week, the best time to look will be between 6 and 6:30 pm local time. By next Sunday, the viewing window will close half an hour later, under a much darker sky.
Once you’ve found Mercury, try looking at it through a small telescope. It will show a waning gibbous (more than half illuminated) phase, and that phase will rapidly wane all week!
The other easy evening planet to see this week is reddish Mars. After dusk, Mars will appear as a medium-bright, reddish pinpoint of light in the lower third of the western sky among the dim stars of Aries (the Ram). The Red Planet will set at about 11:20 pm local time. Mars is slowly shrinking in size and brightness as we increase our distance from it little-by-little.
Last week, Mars passed near Uranus, and it is still positioned only a few finger widths above that far dimmer, blue-green planet. During this week, Mars will move farther away from Uranus. In the meantime, the distant ice giant planet will remain positioned about 1.6 finger widths above the modestly bright star named Torcular (or Omega Piscium). This week, Uranus will set at around 10:45 pm local time.
The sight of three bright planets this week, two of them kissing, might entice you to rise early and peek outside at dawn. All week long, bright Jupiter will be visible in the southeastern sky between 3:30 am local time and dawn. A pretty celestial sight occurs on the pre-dawn mornings surrounding Monday, February 18, when observers will see rapidly descending Venus pass very close to distant Saturn. At closest approach on Monday morning, extremely bright, white Venus will be located 1 finger’s width above dimmer, yellowish Saturn — placing both planets within the field of view of a backyard telescope. At that time, Venus will exhibit a partially illuminated disk. For best results, look for the duo low in the southeastern sky between 6 and 7 am local time.
Evening Zodiacal Light
For about half an hour after dusk during the two week period preceding the new moon on March 6, look west-southwest for a broad wedge of faint light rising from the horizon and centered on the ecliptic. This is the zodiacal light — reflected sunlight from interplanetary particles of matter concentrated in the plane of the solar system. The glow will be centred on the horizon directly below Mars. Try to observe from a location without light pollution, and don’t confuse the zodiacal light with the brighter Milky Way to the northwest.
Astronomy Skylights for the week of February 17th, 2019 by Chris Vaughan.
Keep looking up, and enjoy the sky when you do. I love questions and requests — so, send me some!