The Sky This Week for February 13 to 19

Black catsThe Sky This Week for February 13 to 19

The Winter Hexagon, Venus reaches its greatest brilliancy, and other beautiful things to look for in the sky this week.

By Richard Talcott


Monday, February 13

Although asteroid 4 Vesta reached opposition and peak visibility in mid-January, the brightest minor planet of 2017 still shines at magnitude 6.8 and shows up quite easily through binoculars. To find the minor planet, start at magnitude 1.2 Pollux in northern Gemini and then drop 2.4° southwest to magnitude 4.1 Upsilon (u) Geminorum. Vesta lies 1.4° due south of Upsilon this evening.

Tuesday, February 14

In what seems a fitting tribute, the planet named after the Roman goddess of love shines brilliantly in the evening sky on Valentine’s Day. Venus gleams at magnitude –4.8 and shows up easily in the west-southwest within a half-hour after sunset. It grows even more prominent as darkness settles over the landscape. The planet lies among the background stars of Pisces the Fish, a region that stands some 30° high an hour after the Sun goes down and doesn’t set until 9 p.m. local time. When viewed through a telescope this evening, Venus appears 38″ across and 29 percent illuminated.

Wednesday, February 15

Jupiter rises around 10 p.m. local time and climbs highest in the south about 90 minutes before morning twilight commences. The giant world shines at magnitude –2.3 against the backdrop of central Virgo, some 4° north of that constellation’s brightest star, 1st-magnitude Spica. And this evening, the waning gibbous Moon rises just a half-hour after the planet and follows it across the sky the rest of the night. Even a small telescope reveals Jupiter’s 41″-diameter disk and four bright moons.

Thursday, February 16

Mars continues to put on a nice show these February evenings. It appears 25° high in the west-southwest once twilight fades to darkness, though it’s easier to find by looking 7° (about one binocular field) to the upper left of brilliant Venus. The magnitude 1.2 Red Planet currently lies among the background stars of Pisces the Fish. A telescope shows the world’s 5″-diameter disk, but you likely won’t see any surface detail.

Friday, February 17

Venus reaches greatest brilliancy today, when it shines at magnitude –4.8 (magnitude –4.85, to be more precise). That makes it 10 times brighter than the evening sky’s second-brightest object, Jupiter. Although today marks the inner planet’s official peak, it doesn’t dip below magnitude –4.8 until early March.

Jupiter reaches aphelion at 2 a.m. EST. This is the point in its 12-year orbit around the Sun where it lies farthest from our star, at a distance of 507.2 million miles (816.3 million kilometers).

Saturday, February 18

Last Quarter Moon occurs at 2:33 p.m. EST. Look for it either before dawn this morning (when it lies among the background stars of Libra and looks slightly more than half-lit) or after it rises around 1:30 a.m. local time tomorrow (when it stands near the Scorpius-Ophiuchus border and appears as a fat crescent).

If the Last Quarter Moon looks a little smaller to you today, it may not be your imagination. Our satellite reaches apogee, the farthest point in its orbit around Earth, at 4:14 p.m. EST. It then lies 251,268 miles (404,376 kilometers) from Earth’s center.

Sunday, February 19

One of the sky’s largest asterisms — a recognizable pattern of stars separate from a constellation’s form — occupies center stage on February evenings. To trace the so-called Winter Hexagon, start with southern Orion’s luminary, Rigel. From there, the hexagon makes a clockwise loop. The second stop is brilliant Sirius in Canis Major. Next, pick up Procyon in the faint constellation Canis Minor, then the twins Castor and Pollux in Gemini, followed by Capella in Auriga, Aldebaran in Taurus, and finally back to Rigel.


Astronomy Magazine