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Astronomy

In late November, catch the Pleiades, or Seven Sisters, star cluster visible all night, low in the east-northeast at dusk; high in the south in middle of night; and low in the west-northwest at dawn. The view of this beautiful star cluster through a pair of binoculars is a sight not to be missed!

The brightest stars in November at dusk: Arcturus, the “bear-chaser” star, can still be spotted very low in the west-northwest at dusk at start of November, but disappears below the horizon by second week. Mountains to the west will hasten its departure. Vega is very high in the west-northwest, three-quarters of the way from horizon to overhead on Nov. 1, and still halfway up to overhead at month’s end. Capella, the “mother-goat” star, is very low in the north-northeast to northeast at dusk in November, and slowly gaining in altitude.

Note how stars near the horizon, such as Arcturus and Capella, twinkle much more than stars nearly overhead, such as Vega. The twinkling, as well as the considerable dimming of stars near the horizon, is caused by the passage of their light through Earth’s atmosphere.

Other bright stars at dusk include Altair, high in the south-southwest to west-southwest; it marks the southern point of the Summer Triangle it completes with Vega and Deneb. Fomalhaut, “mouth of the southern fish,” is low in the south-southeast, climbing toward its highest point in the south. Late in the month, Aldebaran, eye of Taurus the bull, begins rising before mid-twilight. Look in the east-northeast, about 14 degrees below Pleiades. Aldebaran’s name is Arabic; it means “the follower,” because that star follows the Pleiades cluster across the sky. (The cluster does not appear on our star maps, because its brightest star is of third magnitude; the maps plot only the stars of first magnitude or brighter, as well as the naked-eye planets.)

Every year around Dec. 1, the Earth passes between Aldebaran and the sun, and the first-magnitude star appears at opposition, nearly 180 degrees from the sun and above the horizon, nearly all night. About 10 days earlier, around Nov. 20-21, the Pleiades star cluster comes to opposition, rising in the east-northeast in deepening twilight. The scene is well described in Alfred Lord Tennyson’s Locksley Hall:

Many a night I saw the Pleiades,

rising thro’ the mellow shade

glittering like a swarm of fireflies

tangled in a silver braid.

As for evening planets: At dusk, Mars is the only planet visible to unaided eye. It glows at first magnitude in the south-southwest to southwest all month. Look 75 minutes after sunset to follow the eastward motion of Mars past the background stars of Sagittarius. On Nov. 4, Mars passes only 0.6 degrees north of the third-magnitude star, marking the top of the teapot. On Nov. 10, Mars passes 2 degrees north of a second-magnitude star in the teapot’s handle.

Venus passed superior conjunction on the far side of the sun on Oct. 25. Wait until just after the sun disappears below your horizon in late November, and start searching for Venus. By Nov. 30, Venus is 9 degrees to the upper left of the sun, and sets 33 minutes after sundown. In December, Venus will become easier to see with the unaided eye—and during spring and early summer of 2015, it will be very impressive indeed.

The moon, full on Nov. 6, draws closer to Aldebaran overnight on the next night, Nov. 7-8, and pulls away from that star on the night of Nov. 8-9, from two hours after sunset until dawn. A waxing crescent moon appears near Mars at dusk on Nov. 25 and 26.

The brightest stars in November at dawn: Jupiter of magnitude -2.1 to -2.2, is very high in the southeast to southwest; Sirius, the “dog star,” is in the south-southwest to southwest; Mercury, -0.6 to -0.9, is low in the east-southeast until it drops below mid-twilight horizon near end of third week; Arcturus is climbing in the east-northeast to northeast; Vega emerges in the northeast at month’s end; and Capella is well up in the northwest.

The huge Winter Hexagon now appears entirely west of the meridian (the north-south overhead line). In clockwise order, its stars are Sirius, Procyon, Pollux (with fainter Castor nearby, not shown), Capella, Aldebaran and Rigel. Betelgeuse, Orion’s shoulder, is inside the Hexagon. Rigel will be the first star of the Hexagon to reach the western horizon, near month’s end. Jupiter and Regulus cross the meridian in pursuit of the Hexagon. Arcturus and Spica ascend the eastern sky all month. Brighter descending Mercury passes 4 degrees north of Spica on Nov. 4, as Spica climbs higher daily.

The moon appears near Aldebaran at dawn on Nov. 8 and 9; widely north of Betelgeuse at dawn on Nov. 10; and between Procyon and Pollux at dawn on Nov. 12. At dawn on Nov. 14, find the last quarter (morning half moon) 5 degrees from Jupiter, with Regulus about 8 degrees east of the bright planet. At dawn on Nov. 15, the moon will appear within 6 degrees of Regulus. On Nov. 19, the waning crescent moon will appear within 3 degrees of Spica. Using binoculars, watch for Mercury rising 13 degrees to the lower left of the moon on Nov. 20, and just 2 degrees to the lower right of the last old crescent moon 40 minutes before sunrise on Nov. 21.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University. He remains active in research and public outreach in astronomy.

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