Contents

The Night Sky in November 2010

By Harry J. Augensen
Professor of Physics & Astronomy, Widener University

Moon’s Phases in Month
  New Moon on the 6th               Full "Frost" Moon on the 21st

Stars and Constellations

November is a splendid month for stargazing, since one can view not only the stars of autumn but also a few remaining summer groups, such as the summer right triangle of Vega, Deneb, and Altair high in the west at dusk, as well as the entire cast of winter stars after midnight. Once our clocks have been set back to Eastern Standard Time on the 7th, coupled with darkness falling progressively earlier each night as autumn progresses toward winter, stargazing becomes possible as early as 5 pm by the end of the month.

 The stars of autumn are in full spendor on November evenings. The Great Square of Pegasus, which consists of four stars, Markab, Scheat, Algenib, and Alpheratz, is high in the south around 8 pm. Alpheratz is actually a member of neighboring constellation Andromeda, but was “borrowed” to complete the square. Below the Great Square is the bright whitish star Fomalhaut in Pisces Austrinus, the Southern Fish. Looking toward the northeast we find the unmistakable “W” shape of the constellation Cassiopeia. Following Cassieopeia is the constellation Perseus, which represents the hero of mythology who rode the winged horse Pegasus and rescued Andromeda from Cetus, the Whale. Cetus is the fourth largest constellation in the sky, but it contains mostly faint stars. One star which is of particular interest is Omicron Ceti, also known as Mira (meaning the Wonderful One), because it varies greatly in brightness. Mira is an enormous red giant star, nearly 350 times larger than our Sun, and it expands and contracts over a period of about 11 months.

One relatively faint constellation that is of historical importance is Aries, the Ram, which lies between Pisces and Taurus. Aries, like Pisces and Taurus, is a member of the zodiac, which means it is one of the constellations through which the Sun passes along the ecliptic path during the course of a year. Currently, the Sun travels within the boundaries of Aries from April 19 through May 13. Over two millennia ago, Aries contained the vernal equinox, the point in the sky where the northward pointing ecliptic crosses the celestial equator, marking the beginning of spring in the northern hemisphere. Due to the effects of precession, the Earth’s slow wobble over a cycle of nearly 26,000 years, that point has since migrated westward into Pisces, but it is still referred to as the first point of Aries. By 2600 AD, the vernal equinox will have shifted further westward into Aquarius.

A few of the magnificent winter constellations can be previewed late on November nights. Low in the east you can find the stars of Taurus, the Bull, which contains the bright reddish star Aldebaran. Aldebaran appears to be part of a “V” shaped cluster of stars known as the Hyades, but it is in reality in the foreground. An even more famous Taurus member is the Pleiades cluster, a compact group of stars shaped like a miniature dipper. Low in the northeast to the left of Aldebaran is the bright yellow-white star Capella (meaning “little she goat”), situated in the constellation of Auriga (the Charioteer). Capella passes nearly overhead during the early morning hours.

 Naked-Eye Planets In the Evening and Morning Sky

In the evening sky, a good pair of binoculars will help pick out Mars just above the southwestern horizon at dusk. Mars is almost as bright as nearby Antares, but both objects are too close (apparently) to the Sun to be easily seen with the naked eye against the bright twilight sky of October. Mars sets roughly one hour after sunset all month. Mercury, like Mars, is quite low in the southwest at dusk as November opens, when it sets only half an hour after the Sun. As the days progress, however, Mercury pulls farther away from the Sun, eventually setting about an hour and a half after sunset by the end of the month. Mercury is roughly six times brighter than Mars, but you will still need an unobstructed western horizon to see it.

Jupiter looks like a brilliant cream-colored star to the lower right of the Great Square of Pegasus, and it easily outshines everything else in the night sky except for the Moon and Venus. Jupiter remains in good position for viewing throughout November, transiting the meridian at about 8 pm and setting at around 1:30 am at midmonth.

In the morning sky, Saturn gets progressively higher above the eastern horizon during November, rising nearly two and a half hours before the Sun on the 1st, and about four and a half hours before it on the 30th. Saturn resembles a bright cream colored star in Virgo, well above the star Spica. Even a small telescope will reveal the beautiful ring system.

After a long run in the evening sky from spring through early autumn, Venus reached inferior conjunction with the Sun on the 29th of October, passing nearly between Earth and Sun on that date. It rapidly shifts into the morning sky, and rises almost half an hour before the Sun on the 1st. By Thanksgiving morning, Venus will be rising about three hours before the Sun, at about 4 am. There is no mistaking this magnificent beacon, as it outshines all other nighttime objects except for the Moon. A telescope or even strong binoculars will reveal Venus’s beautiful crescent phase.

Information on lunar phases and rise/set times of Sun and planets is obtained from the US Naval Observatory Data Services at http://www.usno.navy.mil/astronomy/. Times given apply for observers near to the latitude and longitude of Philadelphia, USA: 40 degrees North latitude, 75 degrees West longitude. 

For more information on astronomy and weather, visit  http://www.widener.edu/stargazing/, then click on Web Links & Resources. A set of free sky maps can be obtained at http://www.skymaps.com/