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The Night Sky of November

Dr. Wayne Wooten
Professor of Astronomy

The moon is last quarter for Halloween, rising at midnight, a little late for trick or treaters. Seasons changing, and Daylight Savings Time ends on November 4th. The waning crescent moon is ten degrees north of Venus on November 5th; note this time last month, Venus was still well up in the evening sky! The moon is new on November 7th, and seven degrees north of Mercury in SW twilight on November 9th. On Veterans Day, the moon is 1.5 degrees north of Saturn, and the first quarter moon is one degree south of rapidly fading Mars on November 15th. The waxing gibbous moon will interfere with the Leonid meteor show, which will peak on the morning of November 18th; wait until after the moon sets about 3 a.m. for best viewing of perhaps a meteor every five minutes out of Leo in the east. The full moon, the "frosty" moon in the days before global warming, happens on November23rd. The last quarter moon rises at midnight on November 29th.

While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up into deep space, far beyond our own Milky Way, binoculars are better for spotting specific deep sky objects. For a detailed map of northern hemisphere skies, about October 31st visit the www.skymaps.com website and download the map for November 2018; it will have a more extensive calendar, and list of best objects for the naked eyes, binoculars, and scopes on the back of the map. Sky & Telescope has highlights of the best events for each week at http://www.skyandtelescope.com/observing/astronomy-podcasts/.

We are losing planets from the evening sky fast. Venus passed below the sun into the dawn sky in late October, and Jupiter is lost behind the sun as well. Mercury is at greatest eastern elongation on November 6th, but gone in the sun’s glare by midmonth. Saturn will likewise be gone by month’s, but Mars will remain in the Sw sky for the rest of the year. The earth is leaving it behind, so it is much smaller, fainter, and more challenging to see any detail now, however.

Setting in the southwest is the teapot shape of Sagittarius, which marks the heart of our Milky Way Galaxy, with Saturn just above the lid of its teapot. The best view of our Galaxy lies overhead now. The brightest star of the northern hemisphere, Vega dominates the sky in the northwest. To the northeast of Vega is Deneb, the brightest star of Cygnus the Swan. To the south is Altair, the brightest star of Aquila the Eagle, the third member of the three bright stars that make the Summer Triangle so obvious in the NE these clear autumn evenings. Use binocs and your sky map to spot many clusters here, using the SkyMap download to locate some of the best ones plotted and described on the back.

Overhead the square of Pegasus is a beacon of fall. South of it is the only bright star of Fall, Fomalhaut. If the southern skies of Fall look sparse, it is because we are looking away from our Galaxy into the depths of intergalactic space.

The constellation Cassiopeia makes a striking W, rising in the NE as the Big Dipper sets in the NW. Polaris lies about midway between them. She contains many nice star clusters for binocular users in her outer arm of our Milky Way, extending to the NE now. Her daughter, Andromeda, starts with the NE corner star of Pegasus’’ Square, and goes NE with two more bright stars in a row. It is from the middle star, beta Andromeda, that we proceed about a quarter the way to the top star in the W of Cassiopeia, and look for a faint blur with the naked eye. M-31, the Andromeda Galaxy, is the most distant object visible with the naked eye, lying about 2.5 million light years distant. Like our own barred spiral, it has a concentration of old yellow giant stars toward the center, but many young blue stars being made from the pink stellar nurseries in its arms. It also has two companion galaxies, M-32 and M-110, much as the Milky Way has the Large and Small Magellanic Clouds for naked eye viewers in our Southern Hemisphere.

To the northeast, Andromeda’s hero, Perseus, rises. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours, as a larger but cooler orange giant covers about 80% of the smaller but hotter and thus brighter companion as seen from Earth. south. Look at Perseus’ feet for the famed Pleiades cluster to rise, a sure sign of bright winter stars to come. This is probably the best sight in the sky with binoculars, with hundreds of fainter stars joining the famed "Seven Sisters" with 10x50 binocs.

In fact, yellow Capella, a giant star the same temperature and color as our much smaller Sun, rises at 7 p.m. as November begins along the northeastern horizon. It is the fifth brightest star in the sky, and a beacon of the colorful and bright winter stars to come.


Prepare for a wonderful Christmas Comet

Get ready for what astronomers are predicting to be a bright, possibly naked eye, Christmastime comet: 46P Wirtanen.

As this comet is slowly closing in on perihelion this December 16 (closest pass by the sun) it will also swing closely by Earth four days later in December and it perhaps might be as bright as 3rd magnitude, or even a bit brighter. That is easily naked eye visible and certainly should be a treat in binoculars.

At 11 million miles from Earth, this will be the 10th closest pass of any comet ever known to Earth when it speeds rapidly by on December 19. But its speed of course is not so fast on any given night as you will see it with the naked eye or even telescopes. As you gaze at this comet among the distant stars telescopically, you WILL be able to watch its position change hour-to-hour as it moves rapidly north-north-eastward each night from far southern skies, into high northern skies by December.

From December 15-18 Comet Wirtanen will be moving between the two magnificent star clusters the Hyades and Pleiades in Taurus, the bull and will be likely naked eye at that time. Note the beautiful rendition offered by astronomers at the Vatican Observatory Foundation for this grouping in the sky, clearly visible with binoculars and a wonderful photographic opportunity.

In early November 46P will be very low and not visible for northern observers, in the constellation of Fornax; however within a few weeks of late November, it will be moving ever-more-quickly into northern skies particularly after the first week of December, where it will move slowly northward through the constellation of Cetus, the Whale.

This comet was discovered in 1948 by astronomer Carl Wirtanen and has a very short orbit around the sun - some 5.4 Earth years to complete one orbit. Since discovery, it has not passed as close to the Earth as in 2018.

Excellent daily updates, including the times of rising, setting and when highest can

Since the comet will be naked eye and quite high in northern skies throughout mid- to late-December, this is an excellent opportunity for all to witness a magnificent miracle in the world of cometary science as this glowing object will pass overhead about one hour before midnight for most of the last two weeks of December. Telescope, binoculars, naked eye and camera equipment will all benefit from the study of this object.

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