This is Dudley Observatory’s Skywatch Line for Friday, November 13, through Sunday, November 15, written by Sam Salem.
On Friday, Sun rises at 6:45am and sets at 4:33pm; Moon rises at 4:28am and sets at 3:55pm. New Moon occurs on Sunday at 12:07am. This new Moon occurs only 17 hours after perigee, the Moon’s closest approach to Earth.
In the eastern pre-dawn sky on Friday, the crescent Moon will sit above Mercury and below much brighter Venus. Look for Virgo’s brightest star Spica, sitting off to the Moon’s right. Then, look for the very bright star Arcturus, in constellation Bootes the herdsman, way off to the upper left. Mercury glows at magnitude –0.7, only slightly dimmer than it appeared just days ago. Mercury now sits just 2 degrees west of magnitude 4 Kappa (κ) Virginis. Nearby is bright Venus about 1.5 degrees southeast of Theta Virginis.
On Sunday, Mars will cease its westward motion through the stars of constellation Pisces, ending a retrograde loop that began in early September. From this point on, Mars will resume regular easterly prograde motion and pass out of Pisces in early January. Mars, at about magnitude –1.8, is a month past opposition and shrinking into the distance. But it’s still 18 arcseconds wide in a telescope. Mars shines bright yellow-orange in the east-southeast at dusk, below the Great Square of Pegasus. It’s at its highest and best in the south around 10pm.
Jupiter and Saturn tilt down in the west-southwest during and after twilight. Saturn is now only about 4 or 5 degrees to Jupiter’s upper left. Watch the two planets creep toward each other for the rest of the fall.
These moonless nights could be a chance to spot Uranus with your naked eyes if you have a clear, dark sky. Uranus, at magnitude 5.7 in constellation Aries the ram, sits high in the east by around 8pm. It sits about 20 degrees lower left of Mars. Uranus is only 3.7 arcseconds wide. But that’s enough to appear as a tiny fuzzy ball, not a point, at high power in a good small telescope. Neptune, at magnitude 7.8 in constellation Aquarius, is equally high in the south at that time you look for Uranus. Neptune is 2.3 arcseconds wide. It’s harder to resolve, except in good seeing conditions.
Spot Altair high in the southwest soon after dark. Brighter Vega shines three or four fists to its right. Two distinctive little constellations lurk above Altair. Delphinus the Dolphin is hardly more than a fist at arm’s length to Altair’s upper left. The second constellation is the smaller, fainter Sagitta the Arrow. It is slightly less far to Altair’s upper right. Use binoculars to help you locate these two little constellations.
Draw a line from Altair to Vega, continue the line onward by half as far. You now point at the Lozenge, the pointy-nosed head of constellation Draco, the Dragon. Draco’s brightest orange star Eltanin is the tip of the Dragon’s nose. It’s always pointing toward Vega.