NIGHT SKY HAPPENINGS

The Sky for November 2016
By Faylene Roth

Dark skies develop early in November once Daylight Saving Time ends. The Milky Way displays a bright east-west band of 1st magnitude stars above the northern horizon from 7-9PM. To the south the faint constellations of the autumn sky—Cetus, Aquarius, Capricornus (east to west)—sprawl loosely across the night sky—no 1st magnitude stars in view unless lonely Fomalhaut (Piscis Austrinus) remains in your viewshed low on the southwestern horizon. The eastern sky brightens up from 9-midnight as the winter segment of the Milky Way rises above the eastern horizon revealing the crowded cluster of the Pleiades, Taurus, Auriga, Orion, Gemini, Canis Minor, and Canis Major. Our neighboring Andromeda galaxy remains visible on clear nights. Find the two stars that form the short northeast leg of Cassiopeia. Extend that line southward to the star at the northeast corner of Pegasus (about 50 ̊). The galaxy is about three-fifths the distance (25-30 ̊) from the top of Cassiopeia to the corner of Pegasus.

Twilight extends the period of daylight in three stages at each end of the day. Morning twilight begins with astronomical twilight—about 1-1/2 hours (nearly 2 during summer months) before sunrise—as the eastern horizon brightens. Nautical twilight continues—as the overhead sky turns blue and color returns to the surrounding landscape—for another 30-40 minutes. The final stage—civil twilight—provides adequate light for most outdoor activities for the half hour before the sun crests the horizon. The opposite progression occurs after sunset.

VISIBLE PLANETS
Evening (Before Midnight)

Mars – The only planet visible this month in the evening sky can be identified as a red orb in a faint region of the southwestern sky. It sets by 11:00pm at the beginning of November and by 10:00pm after Daylight Saving Time ends. Its position does not change much during the month. However, since the constellations rise four minutes earlier each day, the background stars for Mars change over the month from Sagittarius to Capricornus. (Magnitude -0.5)

Morning (At Twilight)

Jupiter – In early November Jupiter rises as early twilight spreads across the eastern horizon. Jupiter rises about three minutes earlier each day, so by month’s end it will appear above the eastern horizon several hours before astronomical twilight begins. At magnitude -1.6, Jupiter is a close match in brightness with the star Sirius (Canis Major) setting on the opposite southwestern horizon. (Magnitude -1.6)

MOON HAPPENINGS
November 7 – Waxing first quarter lights the evening sky then sets soon after midnight.
November 14– Full moon (6:52am) rises at 5:45pm.
November 21 – Dark evening skies return with the waning last quarter moon rising after midnight.
November 29 – New moon (6:18am) yields dark skies for several nights.

(The moon rises later each day—as little as 30 minutes to as much as one hour. Time of moonrise and moonset may also be delayed in mountainous terrain.)

Twilight is often the best time to look for Venus and Mercury because they frequently rise or set within one-half to one hour of sunrise or sunset. Twilight transitions between night and day in three stages at each end of the day. Morning twilight begins with astronomical twilight as the eastern horizon brightens —about 1-1/2 hours (nearly 2 during summer months) before sunrise when the sun is 18 ̊ below the horizon. Nautical twilight takes over for another 30-40 minutes—as the sun passes 12 ̊ below the horizon and the overhead sky turns blue and color returns to the surrounding landscape. The final stage—civil twilight—begins when the sun ascends to 6 ̊ below the horizon and provides adequate light for most outdoor activities for the half hour before the sun crests the horizon. The opposite progression occurs after sunset. Civil twilight covers the period after sunset during which daytime light quality persists for about one-half hour. Color then fades from the landscape during the 30-40 minute period of nautical twilight during which the overhead sky darkens while the western sky retains color. Astronomical twilight then transitions to night skies that are now darkened along the horizon.

Primary Sources: USGS; U.S. Naval Observatory; Your Sky at http://www.fourmilab.ch/yoursky/
To find out when the space shuttle and International Space Station are visible from your location, go to: http://spaceflight.nasa.gov/realdata/sightings/index.html and click on Sighting Opportunities.

The star chart approximates the sky from astronomical twilight to midnight. As the night and month progresses, the constellations shift toward the northwest. The celestial equator is measured in hours (h). The ecliptic is measured in degrees

Note: Hold your hand at arm’s length to measure apparent distances in the sky. The width of the little finger approximates 1.5̊. Middle, ring, and little finger touching represent about 5̊. The width of a fist is about 10̊. The fist with the thumb extended at a right angle equals 15̊. The hand stretched from thumb to little finger approximates 20̊-25̊. The diameter of both the full moon and the sun spans only 0.5̊. Adjust for the size of your hand.