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Fri12132019

Last updateTue, 18 Sep 2018 1pm

February offers beautiful sights for the unaided eye and the eye aided with binoculars—especially for early risers getting out an hour before sunrise.

There’ll be close pairings of the moon with bright Venus just before and after the shortest month of the year—on Jan. 31 and March 2—providing chances to spot Venus in the daytime with binoculars and even the unaided eye. Venus and Saturn will appear just 1.1 degrees apart on Feb. 18. It’ll be worthwhile to watch that pair for changes on several adjacent mornings.

Planets at dawn: The pairing of Venus and the crescent moon on Thursday, Jan. 31, will be unusually close and very striking, before dawn and even long after sunrise. From the Coachella Valley, Venus and the center of the moon’s disk will be just 1.5 degrees apart and closing at 5 a.m. Sunrise occurs in Palm Springs at 6:43 a.m., with Venus just more than a degree from the moon’s center, or three-quarters of a degree from the moon’s edge. The closest approach of the moon and Venus occurs in daytime, between 9:45 and 10 a.m., with Venus about 0.4 degrees—less than the moon’s half-degree width—from the moon’s northern cusp the (upper point of the crescent). From 8:30 a.m. through 11:15 a.m., Venus will appear no more than a moon’s width from the moon’s edge. A telescope at low power will fit Venus and the moon in the same field, with Venus showing a gibbous disk, 62 percent illuminated.

At the next, wider moon-Venus pairing on March 2, Venus will appear nearly 4 degrees to the lower left of the moon. A telescope then shows the planet’s phase increased to 73 percent full, but reduced in apparent size as it will be more distant from Earth.

Near the dates of these moon-Venus pairings, the moon can be seen close to two other planets in the morning sky: The moon will appear 5 degrees to the upper right of Jupiter on Jan. 30; 4 degrees to the lower left of Saturn on Feb. 2; within 2 degrees above Jupiter on Feb. 27; and 2 degrees to the upper right of Saturn on March 1.

Planets, stars and moon at dusk: Mars is high in the southwest to west-southwest, halfway or more from horizon to overhead. While fading slowly from magnitude +0.9 to +1.2, Mars is bright enough not to be confused with any star while the red planet passes through the background of Pisces and Aries. The brightest star nearby is second-magnitude Alpha in Aries, about 10 degrees north of the planet in late February. Begin looking for Mercury emerging from the far side of the sun around Feb. 10, when it shines at magnitude -1.3 and sets south of west at mid-twilight, about 40 minutes after sunset. Still bright at magnitude -0.3 when it climbs to 9 degrees up at mid-twilight on Feb. 26, Mercury then begins to fade more rapidly. It’s still magnitude 0.0 on March 1, but, moving to the near side of the sun and becoming a backlighted crescent, it fades beyond magnitude +1 by March 5 and drops back into bright twilight.

Stars and moon: The moon is visible at dusk from Feb. 5 (very low in the west-southwest in early dusk), through Feb. 19 (just past full, risen north of east). The moon passes 6 degrees south of Mars in Aries on Feb. 10; 1-2 degrees north of Aldebaran in Taurus on Feb. 13; 7 degrees south of Pollux on Feb. 16; and 7 degrees above Regulus in Leo at dusk on Feb. 18. That evening, the Earth passes between the sun and Regulus, and that star appears at opposition, 180 degrees from the sun. The direction of Earth’s orbital motion around the sun on this night is away from the Pleiades in the evening sky and toward a spot about 3 degrees west of the third-magnitude star Beta in the head of Scorpius in the morning sky. At the end of February, our planet is moving away from Aldebaran, eye of Taurus, and toward Antares, heart of Scorpius.

The huge Winter Hexagon occupies much of the southeast quadrant of the sky at dusk. Start with Sirius, its brightest star, and go clockwise around its perimeter, to Procyon, the Twins (Pollux and Castor), Capella, Aldebaran, Rigel and back to Sirius. Orion’s shoulder Betelgeuse is inside. Regulus rises into view at dusk during February and chases the Hexagon across the sky. Note Regulus about to set in the west on the morning twilight chart, available with the online version of this article.

Check the website of the Astronomical Society of the Desert at www.astrorx.org for dates and times of our evening star parties at two locations:Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, Feb. 2. The primary, more-accessible location is the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within 4 miles south of Highway 111 in Palm Desert). The next session there is on Saturday, Feb. 9, from 6 to 9 p.m. Listings of star parties on the website include maps and directions for both locations. Star parties can be cancelled in poor observing weather.

Also, remember to check the Impromptu Star Parties link on the webpage. I’ll be offering sky watches in Palm Springs at the pedestrian bridge over Tahquitz Creek at North Riverside Drive and Camino Real, including some at predawn to follow the three morning planets, and some at dawn or dusk to observe the moon’s conjunctions with planets.

Abrams Planetarium publishes a monthly Sky Calendar with an evening sky map. Subscriptions are $12 per year at www.abramsplanetarium.org/skycalendar for three printed issues mailed quarterly.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller 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.

Published in Astronomy