November 2017 features twilight planetary pairs—one in the morning, and one in the evening.
Venus and Jupiter will appear close together low in the east-southeast morning twilight glow for a few mornings around Nov. 13, about 40-45 minutes before sunrise. In last 10 days of the month, Saturn and Mercury will appear within the same binocular field low in the southwest evening twilight glow, 40-45 minutes after sunset.
Of the morning planets, dim, distant Mars rises in a dark sky all month, improving from 2.6 hours before sunup on Nov. 1, to 3.5 hours at month’s end. Mars glows at magnitude +1.8 to +1.7, about as faint as it ever gets. Brilliant Venus, of magnitude -3.9, rises in ever brighter twilight, 1.3 hours before sunup on the 1st, and about 45 minutes hour before sunup on the 30th. Watch for Venus’ rising 16 to 34 degrees to the lower left of Mars as November runs its course.
On Nov. 2, binoculars readily show the star Spica rising in the twilight glow 3.5 degrees to the lower right of Venus. The other morning planet, Jupiter, at magnitude -1.7, is lost in the sun’s glare well below Venus in first few days, but from Nov. 8-18, may be found in the same binocular field as Venus. The two bright planets appear closest on Monday, Nov. 13, with Jupiter just one-third of a degree to the upper right of Venus. This month, on Nov. 29, Jupiter will rise in a dark sky just more than two hours before sunrise. As Venus rises in twilight that morning, Jupiter will appear 17 degrees to the upper right of Venus and 17 degrees to the lower left of Mars, midway between them.
Bright stars in morning twilight feature the huge Winter Hexagon of bright stars moving into the west. Sirius, the Dog Star, is its brightest and southernmost member. Orion’s red Betelgeuse lies inside the Hex, and Leo’s Regulus, high in the south-southeast to south, trails behind it. Bright Arcturus in the east-northeast to east, and Spica in the east-southeast to southeast, round out the list of 10 stars of first magnitude or brighter visible in all of November’s dawns. An 11th star, Vega, rises in the northeast late in the month, far to the lower left of Arcturus.
Around Nov. 21, our Spaceship Earth is heading directly toward the star Regulus. Go outdoors in the morning, and visualize our planet’s motion around the sun, and the motions of faster-moving Venus, the next planet inside Earth’s orbit, and slower-moving Mars and Jupiter, the planets next outside our orbit. If we could look “down” from “above” the solar system, the planets would appear to revolve counterclockwise around the sun. All the morning planets are ahead of us. Venus is moving even farther ahead, and will pass on the far side of the sun in January 2018. We’re gaining on Jupiter and Mars, and will overtake them next year.
Bright stars in evening twilight in all of November include the Summer Triangle, with Vega, Altair and Deneb passing west of overhead; and Fomalhaut, mouth of the Southern Fish, low in the southeast to south-southeast. Quickly slipping out of view early in the month are Antares, in the southwest to the lower right of Saturn, and Arcturus, in the west-northwest. Rising into view are Capella in the northeast, and Aldebaran in the east-northeast.
Evening planets: Saturn (magnitude +0.5) on Nov. 1 sets in a dark sky 2.7 hours after sunset, and telescopes reveal its rings tipped as much as possible, 27 degrees from edgewise. But Saturn sets ever earlier, sinking close to brighter Mercury (magnitude -0.4 to -0.1) in the latter half of the month. Mercury appears to the lower right of Saturn, by 10 degrees on Nov 17, and 7 degrees on Nov. 20. On Nov. 23, Mercury reaches greatest elongation—22 degrees from the sun and 4.7 degrees below Saturn. Thereafter, Mercury appears to the lower left of Saturn, by 4 degrees on Nov. 24, and 3 degrees on Nov. 28. This is quite an unfavorable appearance for our solar system’s innermost planet, as it remains mired low in twilight.
The moon is full on Friday, Nov. 3, and rises north of east a few minutes after sunset. Two nights later, on Sunday, Nov. 5, the waning gibbous moon rises in the east-northeast within two hours after sunset. Using binoculars, look for the reddish-orange star Aldebaran, eye of Taurus the Bull, close to the moon’s upper right. That night, the moon will gradually creep eastward against the background stars, away from Aldebaran. By an hour before sunrise on Monday, Nov. 6, the moon and star will be in the western sky, with the moon 6 degrees above the star.
Follow the moon daily an hour before sunup. On Nov. 8 and 9, watch it leap over the line connecting the Twins (Pollux–Castor) to Procyon. On Nov. 11, it stops just short of Regulus, heart of Leo. That morning, binoculars will show Regulus just east of the fat crescent moon. As seen from Palm Springs through a telescope that day, the leading bright edge of the moon covers the star at 8:55 a.m., and the moon’s trailing dark edge, invisible in daylight, uncovers it at 10:01 a.m.
By Nov. 11, you’ll want to look low in the east-southeast 40 to 60 minutes before sunrise each morning for a week, to follow the progress of the Venus-Jupiter pair. That morning, Jupiter appears 1.9 degrees to the lower left of Venus. On Sunday, Nov. 12, Jupiter appears just 0.9 degrees directly below Venus. Their closest pairing occurs on Monday, Nov. 13, with Jupiter now only one-third of a degree to the right of Venus and slightly higher. Jupiter is getting higher each day, Venus lower.
On Tuesday, Nov. 14, Jupiter appears 1.3 degrees to Venus’ upper right. By that morning, you can find faint Mars 6-7 degrees below the moon. On Nov. 15, find the crescent moon within 7 degrees to the lower left of reddish Mars and within 7 degrees to the upper left of blue-white Spica, forming a beautiful triangle with them. Some 17-19 degrees to the moon’s lower left, find the Venus-Jupiter pair still within 2.3 degrees apart. On Thursday, Nov. 16, in possibly the prettiest scene, Jupiter and Venus are 3.3 degrees apart, within 6 degrees to the lower right and 9 degrees below the moon. On Friday, Nov. 17, the moon’s final morning, look about 40 minutes before sunrise to spot the very thin old crescent within 5 degrees to the lower left of Venus. Jupiter will be 4.4 degrees to Venus’ upper right. Since the new moon occurs the next day, Nov. 18, at 3:42 a.m., a sighting of the moon on the morning of Friday, Nov. 17 will be about 22 hours before new.
Start looking for the young moon in the early evening on Sunday, Nov. 19. About 40 minutes after sunset, find the thin crescent very low in the west-southwest, with Mercury about 8 degrees to its left and a little lower. Saturn will be 12 degrees to the moon’s upper left and 8 degrees to the upper left of Mercury. The moon’s age will be nearly 38 hours after new. On the following evening, Nov. 20, seeing the moon should be very easy, as it sets in a dark sky nearly two hours after sunset. You still need to look early in twilight to catch Mercury, 8 degrees below the moon. Saturn will be 2 degrees to the moon’s lower left.
On the night of Nov. 21, Earth passes between the sun and the Pleiades (Seven Sisters) star cluster. Within an hour after sunset that evening, face east-northeast—opposite to the sun’s direction below the west-southwest horizon—and watch the Pleiades emerge and ascend in the deepening twilight. The scene is well described in lines by Alfred Lord Tennyson.
To celebrate the occasion of the Venus-Jupiter pairing, members of the Astronomical Society of the Desert are offering sky watches on Monday, Nov. 13, and the next four mornings, as the crescent moon passes through the gathering of three planets and a star, and the Venus-Jupiter pair grows wider each day. The sessions will be held from 5:15 until 5:45 a.m., on the pedestrian bridge crossing over Tahquitz Creek, at Camino Real between North and South Riverside drives, three blocks north of Cahuilla Elementary School. The session is dependent on sky conditions. If the sky is clear, we’ll be there, with telescopes and binoculars.
The website of the Astronomical Society of the Deserthas a listing of our evening star parties at two locations. The primary, more accessible location is at the Visitor Center (VC) of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). Sessions are scheduled there on Saturdays, Nov. 25 and Dec. 23, from 5 to 8 p.m. Sawmill Trailhead (SMT), our high-altitude site (elevation 4,000 feet—wear warm clothes), will have star parties starting at dusk on Saturdays, Nov. 11 and Dec. 9.
This year’s Night Sky Festival at Joshua Tree National Park will be held Nov. 10-12. For details, visit www.nps.gov/jotr/planyourvisit/night-sky-festival.htm. Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.
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 school children in and around Palm Springs. 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.