1. Highlighting the Near and Deep Sky
What’s Up E W
Highlighting the Near and Deep Sky
December , 2016 S

2. General Information December 2016
This Month:
It’s the time of the Winter Solstice, marking the change of seasons.
Yet autumn’s star patterns still occupy our main viewing area as twilight ends—winter’s are rising in the east and summer’s setting in the west.
Brilliant Venus and first-magnitude Mars are readily visible to the naked eye. Uranus, at the edge of naked-eye visibility, and more distant Neptune, which requires at least binoculars to spot, are also in the sky.
Stretching from Auriga in the northeast to Sagittarius in southwest, the Milky Way passes high overhead.
Sunset Range: 5:02 p.m. (Dec. 1st) to 5:13 p.m. (Dec. 31st).
End of Astronomical Twilight (Full Darkness* – Sun 18° below horizon): 6:35 p.m. (Dec. 1st) to 6:46 p.m. (Dec. 31st).
* Usually dark enough for observing about a half hour before this.

3. Moon Phases December 2016 Wed., 7th – First Quarter
Tue., 13th – Full Moon
Tue., 20th – Last Quarter (Fri./Sat. observing opportunities Dec. 16th/17th)
Thu., 29th – New (Fri./Sat. observing opportunities Dec. 23rd/24th)
Roughly speaking:
First Quarter Moon is highest at sunset and sets at midnight
Full Moon rises at sunset and is in the sky all night
Last (“Third”) Quarter Moon rises at midnight and is highest at dawn
New Moon sets at sunset and is absent from the sky all night

4. Celestial Events December 2016
Sun., 4th – Earliest end of evening twilight for the year.
Wed., 7th – Earliest sunset for the year.
Wed., 12th/13th – Waxing gibbous moon occults Aldebaran (first contact about 23:00:13 on 12th, last contact at about 00:14:12 on 13th).
Tue./Wed., 13th/14th – Geminid Meteor Shower. Usually strong and reliable (peaks as high as 120 meteors/hour), but this year all but the brightest are hidden by full moon.
Sun., 18th – Usually mag. 2.1, Algol (β Persei) at minimum mag. 3.4 for about 2 hours centered on 10:46 p.m. EST. (Minima every 2d 20hrs 49 min.)
Wed., 21st, 5:44 a.m. – Winter Solstice. Shortest day of the year.
Wed., 21st – Algol again at minimum for about 2 hours centered on 7:35 p.m. EST.

5. (~30 min. before full darkness)
Dec. 15th, 6:00 p.m.
(~30 min. before full darkness)
For tonight, Nov. 21st , 6:00 p.m. is also about 30 min. before full darkness.
Keystone
Directly Overhead
(“zenith”) E
Nov. 21st W
Ecliptic
Nov. 21st
Uranus
Neptune
Mars
Venus S

6. What’s Up programs are posted on the RVAS Website!
Find them under “Tips and Topics” or at:
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