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November skies reveal the winter constellations of Cassiopeia and Pegasus
By Dr.Wayne Wooten Special to Splash! magazine
November 8th has Mercury crossing the front of the Sun from 1:12 PM CST until sunset locally. The Escambia Amateur Astronomers will be set up outside PJC's planetarium for public viewing of this rare event. But there are other events of note for sky observers locally this month as well.
For November, the Moon will be full on November 4th, so the first week will find the Moon waxing and getting brighter and setting later each evening. In native American tradition, this is the "Hunters Moon", full moon for turning game into dried meat for winter. Unfortunately there are no bright planets in the evening sky currently, although Venus comes back from behind the Sun in December. So the last three weeks will be good for deep sky observing of both our own and other galaxies.
While the naked eye, dark adapted by several minutes away from any bright lights, is a wonderful instrument to stare up at the Galaxy arching overhead, binoculars are better for spotting specific deep sky objects all along the plane of the Galaxy. For a detailed map of northern hemisphere skies, about November 1st visit the www.skymaps.com website and download the map for November; 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.
 | | Ed Magowan special to Splash! M-33, the fine "Pinwheel" Galaxy, is large but faint, and definitely needs binoculars and a dark night to spot, above. |
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Overhead we see the spiral arm of the Galaxy we are moving through, look for Cygnus the Swan. You will notice a dark rift of dust cutting the spiral arm down the middle. We, the solar system, are heading into that rift at 250 km/sec as we orbit the Galaxy's core in Sagittarius.
But Sagittarius is now setting as the SW as twilight ends, so from our own Galaxy, we turn in fall to the galaxies far beyond our own.
Fall reveals new constellations rising in the east now, including the Great Square of Pegasus. From the NE corner star of the square, find the three stars in a row for Andromeda, and from its middle star, go to the upper left toward the top star of the "W" shape of bright
Cassiopeia, rising in the east to replace the Big Dipper, now setting in the NW. The faint oval blur you see is M-31, the Andromeda Galaxy, visible with the naked eyes and at 2.5 million ly. distance, the farthest you can see with eyes only. Large amateur scopes reveal two companion galaxies, M-32 and M-110, and dust lanes in this nearby spiral very similar to the dust you saw overhead in Cygnus in our home galaxy.
South of M-31 is M-33, the fine "Pinwheel" Galaxy. It is large but faint, and definitely needs binoculars and a dark night to spot. A wonderful photo of it by EAAA club president Ed Magowan is attached.
In the SE is NGC 253, the "Silver Dollar" Galaxy, south of Diphida, the brightest star in Cetus the Whale. It looks nice in binoculars, and reveals dust lanes well is scopes 6" or larger at about 50X.
The most famous variable star is the eclipsing binary Algol in Perseus.
Here an orange giant star orbits with a smaller but hotter and brighter blue star every 70 hours. When the cooler star cover most of the surface of its brighter companion, the light drops to 1/3 its normal brightness, a change easily noted with the naked eye. In fact, the Arabic title "Al Gol" (the ghoul) tells us a thousand years ago Arabic stargazes marveled at its changes. For November, the minima occur at 9:18 PM on November 5th, 6:07 PM on November 8th, 11 PM on November 25th, and 7:49 PM on November 28th. The star seems to begin fading from 2nd magnitude (about as bright as Polaris, the north star) down to third magnitude three hours before the minima, and resume normal brightness about three hours after the minima. These two stars orbit so close to each other that neither is spherical, but both are egg-shaped ellipsoids, facing each other's long axis.
Two of the finest star clusters in the sky are well placed now.
Between the W of Cassiopeia high in the NE and Perseus is the "Double Cluster", a faint blur in the Milky Way with the naked eye, but fine in 10X binoculars . Both clusters lie about 7,000 light years away, in an outer arm, the Perseus spiral arm. Below Perseus in the east rises the famed "Seven Sisters", the Pleiades Cluster. About 250 light years distant, this cluster contains at least 200 stars, and dozens are visible with even the smallest binoculars . It does look like a "little dipper" as it rises, but the real "Little Dipper" lies to the west of Polaris in the northern sky. Long exposures reveal the star cluster passing through a dusty region of our own spiral arm, so the stars are enveloped in a faint, ephemeral cloud in space.
Winter is coming. As the Pleiades rise in the east, to the north bright yellow Capella rises. It is the same 6,000 K temperature as our own Sun, so it appears as our Sun would, seen from a distance of 4 light years (such as the closest other star system, Alpha Centauri). Next month, Orion and company join our star show.
For more information, including a free packet with many nice handouts donated by Astronomy magazine, call the PJC sponsor, Dr. Wayne Wooten, at (850) 484-1152, or e-mail him at wwooten@pjc.edu; the club's website is at www.eaaa.net . Keep looking up!
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