One bright planet, Jupiter, is visible briefly in the evening (soon to depart)—along with a great many bright stars! In the morning, Venus is at its best and brightest for the year, and showing crescent phases within easy reach of binoculars and small telescopes. Faint Mars edges ever closer to Venus until mid-March. Mercury is visible all month to the lower left of Venus, but binoculars and an unobstructed view toward the east-southeast will make it easier. Fainter Saturn, squeezing in at month’s end, will replace departing Mercury in March.
A ride on Spaceship Earth on Feb. 18 has the sun on our left, Regulus on our right, the head of Scorpius almost straight ahead, and the Pleiades cluster directly behind. The North Ecliptic Pole, in Draco, directly “above” Earth’s orbit, is overhead. Off we go, at 1/10,000 the speed of light. Venus is going even faster, and is therefore pulling away from us, and we will pass it on the far side of the sun in October. Mars is going slower, so we’ll overtake it in December.
February opens with only one bright planet, Jupiter, in the evening sky, shining at magnitude -2.1 and 14 degrees up in west-southwest sky at dusk mid-twilight on Feb. 1. It will drop 5 degrees lower each week at the same stage of twilight, about 40 minutes after sunset. Jupiter will be gone by the end of the third week—even sooner if the San Jacinto Mountains block your view.
But there are plenty of bright stars! On our evening twilight map, connect the dots at the east (left) ends of these star trails, in clockwise order, beginning and ending with its brightest star: Sirius, Procyon, Pollux, Castor, Capella, Aldebaran, Rigel and back to Sirius. When you do so, you will have drawn the Winter Hexagon at evening mid-twilight on Feb. 1. Its location on Feb. 28 can be drawn by connecting the west (right) ends of the same trails, in the same order.
About 40 minutes after sunset, lie down with your feet toward the south. Sirius, the hexagon’s southernmost star and the brightest in the entire sky, shines at magnitude -1.5, but it is not as bright as Jupiter. The Hexagon seems to have a seventh star, Castor, which actually doesn’t quite make the grade as a first-magnitude star, but we include it because it’s only 4.5 degrees from his brighter twin, Pollux.
Note the bright star Betelgeuse insidethe Hexagon. It marks the brighter shoulder of Orion, and Rigel marks the brighter foot. Midway between them is a striking, nearly straight line of three stars not quite three degrees long, marking Orion’s belt. Extend the belt toward the southeast, and you’ll find Sirius, the Dog Star. Extend the belt in the opposite direction, bending north a bit, and you’ll find Aldebaran, eye of Taurus, the Bull, westernmost star of the Hexagon; go 14 degrees beyond it, to the Pleiades or Seven Sisters star cluster, a beautiful target for binoculars. The Arabic name, Aldebaran, means “the Follower” (of the Pleiades). Next in brightness is Capella, the “Mother Goat star” and northernmost member of the Hexagon.
Follow the moon nightly at dusk from Feb. 2-16. On Feb. 2, the easy, 5% crescent will be 4 degrees to Jupiter’s lower left. Watch the waxing gibbous moon hop through the stars of Taurus, the Bull, Feb. 8-10. On Feb. 8, the 55% moon is about 6 degrees from the Pleiades. On the next evening, the 64% moon is about 6-7 degrees northwest of Aldebaran, and on Feb. 10, the 73% moon is within 5 degrees to the southeast of 1.7-magnitude Elnath, the tip of the northern horn. On Feb. 13, the 93% moon is within 4 degrees to the southeast of Pollux, the brighter of the “Twin” stars of Gemini. On Feb. 16, the moon, 100 percent illuminated and just past full, is within 6 degrees to the lower left of Regulus, heart of Leo, the Lion.
This star follows the Winter Hexagon across the night sky. Regulus rises north of east into early evening view during February. Our home planet passes between the sun and Regulus each year around Feb. 18, when the star appears at opposition, 180 degrees from the sun, and is above the horizon all night. You’ll find Regulus also on the morning map, low in the western sky.
February’s morning sky: For the next several months, the morning sky is where the action will be, with many striking planet pairings and gatherings of the moon and planets.
Just four to five weeks after its inferior conjunction, or its passage nearly between the Earth and sun on Jan. 8, Venus attains a spectacular peak brilliance of magnitude -4.9 from Feb. 5-14, rises in a dark sky all month, as much as 2.6 hours before sunrise, and attains its highest position in morning twilight around Feb. 20.
Venus is worthy of several closeup looks with optical aid this month, while it’s still quite near to Earth. The planet’s crescent phase is easily resolved with a small telescope or even a pair of 7-power binoculars. Simply find Venus when it’s easy to spot in the east-southeast before dawn, and keep track of it as the sky brightens with the approach of sunrise. During February, Venus’ crescent fattens from 16 percent to 38 percent full, while shrinking in size from 49 to 32 arcseconds tip-to-tip as Venus races away from Earth. Don’t miss it! The next chance will occur around the inferior conjunction of August 2023.
Ranking next in brightness after Venus in February’s morning sky are two zero-magnitude stars: Golden Arcturus, high in the southwest, and blue-white Vega, high in the east-northeast. Except for its low altitude and consequent dimming by our atmosphere, Mercury would compete with these stars after its brightening during the first week.
Mars glows dimly at magnitude +1.4 to +1.3 this month. Venus—rounding the sun while moving away from us, with Mars in the background—makes the two planets appear close together in our sky for an extended time. Mars appears to the lower right of Venus, by 9 degrees on Feb. 1, 7 degrees on Feb. 9, 6 degrees on Feb. 19, and 5 degrees on March 1. They’ll appear closest, 3.9 degrees apart, in mid-March.
Mercury, emerging from its inferior conjunction of Jan. 23, brightens to magnitude +1.0 by Feb. 1, and further to +0.5 on Feb. 4, 0.0 on Feb. 11, and -0.1 on Feb. 18 through early March. Mercury climbs highest for this apparition—only 8 degrees up in mid-twilight from Southern California—around Feb. 10, and reaches greatest elongation from the sun, 26 degrees, on Feb. 16. Binoculars will come in handy to spot the innermost planet during this moderately unfavorable appearance. Find it to lower left of Venus, by 14 degrees on Feb. 1, and 13 degrees during Feb. 3-9. On Feb. 12, Mercury is 14 degrees to the lower left of the Venus-Mars pair, then 6.6 degrees apart, and forms an isosceles triangle.
Follow the moon in the morning sky during Feb. 15-28. On Feb. 16, the full moon appears 6 degrees to the upper right of Regulus. On Feb. 20 and 21, the waning gibbous moon visits widely to the upper right and then to the upper left of Spica. On Feb. 24, the 43% fat crescent moon is 5 degrees to the upper left of Antares.
On Feb. 27, the 13% crescent visits 10 degrees to the lower right of Venus and 5 degrees below Mars. Binoculars will be required to spot +0.8-magnitude Saturn, 4 degrees to the lower left of Mercury.
On the next morning, Feb. 28, the 6% crescent is very low, 19 degrees to the lower left of Venus and 6 degrees to the lower right of Mercury. Mars is 5.1 degrees to the lower right of Venus. Saturn rises 3-4 minutes earlier each day and gets easier to see, while Mercury rises ever closer to the time of sunrise.
Note to readers: I am curious to know whether a significant number of our readers get out to observe morning sky events. The next few months will be rich with predawn planets; for example, on mornings in the latter half of June, all five bright planets, plus the two telescopic ones discovered in 1781 and 1846, will be visible within a one-hour interval overlapping predawn darkness and twilight. Let me know your thoughts in the comments below.
Illustrations of many of the events described above appear on the Abrams Planetarium monthly Sky Calendar. To subscribe for $12 per year or to view a sample copy, visit www.abramsplanetarium.org/skycalendar.
Robert Victor originated the Abrams Planetarium monthly Sky Calendar in October 1968, and still produces issues occasionally. He enjoys being outdoors sharing the wonders of the night sky, and is hoping for the pandemic to end! Robert Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.