To the reader:
The Skywatcher's Diary for January 1999 has been prepared by
Robert C. Victor. Credit to the author and to
Abrams Planetarium,
Department of Physics and Astronomy at
Michigan State University, and mention of our
Sky Calendar, would be appreciated.
A sample issue of the Sky Calendar is available over the Internet. It
can be viewed via the World-Wide Web at
http://www.pa.msu.edu/abrams/SkyCalendar/Index.html
If you would like a printed sample of the January issue, please send a long,
self-addressed stamped envelope to:
January Sky Calendar
Abrams Planetarium
Michigan State University
East Lansing, MI 48824
Each month, the Department of Physics and Astronomy at Michigan State
University makes the Skywatcher's Diary available over the Internet. It can be accessed at
http://www.pa.msu.edu/abrams/SkyWatchersDiary/Diary.html
Current and back-issues of the Skywatcher's Diary are available in our archives
at
http://www.pa.msu.edu/abrams/SkyWatchersDiary/Archives.html
ftp://www.pa.msu.edu/pub/swd/
Follow the striking lineup of three bright evening planets, 90 degrees
long on Jan. 1, 54 degrees long by Jan. 31. Brilliant Venus, very low
in WSW at dusk, gets higher as month progresses. After midmonth,
Venus sets in a dark sky, after twilight ends. Bright Jupiter is in SSW
to SW at dusk, 55 to 23 degrees upper left of Venus. These brightest
planets will form a spectacular pair in late February, to be described
in next month's Diary. Saturn is high in SE to SSW at dusk, 35 to 30
degrees E (upper left) of Jupiter.
Mars is now in morning sky, high in S to SSW an hour before sunup.
In 1999, Mars will outshine magnitude 0 for five months, March
through July, and outshine mag. -1 in April and May, even exceeding
Sirius for about a month. In the first six months of this year, there'll be
an interesting "double pairing" with the first-magnitude star Spica: First,
Mars passes 4 degrees N of the star in a bonafide conjunction in
morning sky on Jan. 12. After Mars goes 19 degrees east of Spica in
March, it comes back for a long "quasi-conjunction" within 1.7 degrees
from the star in the evening sky in early June, before resuming eastward
motion. A chart of the path of Mars against background stars from
January through mid-August appears on our January Sky Calendar.
Try this astrophotography project: Motion of Mars. Using a 35-mm
camera with a standard lens (about 50-mm focal length), take a series of
photographs or slides to record the apparent motion of Mars against the
stars. Use a tripod to steady the camera, and fast film such as
Ektachrome 400. Aim camera midway between Spica and Alpha Librae
and orient the frame so that a line connecting these stars is "horizontal,"
or parallel to the longer sides of the frame, and midway between them.
Adjust your aim until Spica is right of center, and Alpha Librae at same
distance left of center. Take two or three photos per month, covering at
least the interval from Jan. 12 to Aug. 7. Exposures of about 20 or 30
seconds should be about right. Take your first photo no later than
Jan. 12, when Mars first passes Spica, and your last photo no earlier than
Aug. 7, when Mars finally passes Alpha Librae. Your series will record
the fascinating "S"-shaped path of Mars and its quasi-conjunction with
Spica, as well as the planet's spectacular changes in brightness.
Skywatcher's Diary: January 1999
The Moon rises within a few minutes before or after sunset from
continental U.S. The first of two Full Moons this month occurs tonight
at 9:49 p.m. EST. (See January 30 and 31.) An hour after sunset,
Orion's shoulder Betelgeuse is in the east, 16 degrees to the Moon's
right. Pollux and Castor, the Gemini twins, are about 17 degrees to
Moon's left.
The Moon rises in ENE about an hour after sunset, as seen from lower
Michigan. Look 10 degrees lower right of Pollux, the brighter of the
Gemini twins. Two hours after sunset, watch for Procyon rising just
north of east, 13 degrees to Moon's lower right. Its name means "before
the dog." How soon after you find Procyon can you spot brilliant
twinkling Sirius, the "Dog Star," rising in ESE? Orion's belt points the
way down to this brightest of nighttime stars.
An hour before sunrise on Monday, look for the reddish star Antares
low in SE. Mercury is rising 17 degrees to the star's lower left.
Four-and-a-half hours after sunset, look in the east to find Regulus,
heart of Leo, 6 degrees lower left of the waning gibbous Moon. For the
rest of the night, the Moon closes in on Regulus. By an hour before
sunup on Tuesday, from lower Michigan, they're 2 degrees apart in
WSW. From Hawaii, the Moon will cover the star before sunrise
Tuesday.
At dusk, locate brilliant Venus low in SW to WSW. As sky darkens,
find Altair in W, 31 degrees upper right of Venus. The other naked-eye
planets visible at dusk are bright Jupiter in SSW, 51 degrees upper left
of Venus, and Saturn in SSE, 34 degrees upper left of Jupiter. These
three planets lie in a nearly straight line 85 degrees long. Watch the line
shorten in coming weeks as Venus closes in on Jupiter and Saturn.
Four-and-a-half hours after sunset, the waning gibbous Moon, just
risen, is about 10 degrees north of east. Look for Regulus 7 degrees to
Moon's upper right, or above it from southern U.S.
An hour after sunset on Thursday, the waning gibbous Moon is in SW,
while reddish Mars and blue-white Spica are less than 5 degrees apart in
the south. Binoculars enhance their colors. A line from Mars to the
Moon, extended, points to Regulus in WSW.
An hour before sunup on Friday, the Moon, just over half full, is in
SSW. Mars and Spica are less than 4-1/2 degrees apart in the south,
some 15 to 20 degrees to Moon's lower left.
Opens 8:00 p.m. tonight at Abrams Planetarium: Celestial Preview
1999.
This live, informal show, is presented two weekends only, January 8-10
and 15-17: Fridays and Saturdays at 8:00 p.m. and Sundays at 4:00
p.m. Using our Digistar projector, we'll preview the best of the year's
evening events: Spectacular planet gatherings in the first half of 1999,
the unusual brilliance of Mars in spring, and of Jupiter and Saturn in
autumn, their best showings in several years. Our family show, Rusty
Rocket's Last Blast, will be presented Sundays at 2:30 p.m., beginning
January 10. For a recorded message about our shows, call (517) 355-
4672.
An hour before sunrise on Saturday, the Last Quarter Moon is the the
southern sky with Mars about 5 degrees to its lower left, and Spica just
over 4 degrees below Mars. At sunrise the Moon is 90 degrees or one-
quarter circle to the right of the rising Sun. Note the Moon is half
illuminated.
An hour before sunup on Sunday, the fat crescent Moon is in south,
with Mars 7 degrees to its right. Spica is about 4 degrees above
Mars. Watch Mars slowly creep eastward past Spica over the next few
mornings.
Bright Jupiter is in SW at nightfall. Early this week, Jupiter forms an
isosceles triangle with the south side of the Great Square of Pegasus,
Alpha and Gamma Pegasi. Jupiter is 21 degrees from both stars.
On Tuesday morning, Mars and Spica appear closest, 4 degrees apart.
Face south just over an hour before sunrise.
An hour before sunrise on Wednesday and Thursday, find a thin
waning crescent Moon in the southeast with earthshine on its dark side.
On Wednesday, reddish Antares, heart of the Scorpion, is within 10
degrees below or lower right of the Moon.
An hour before sunrise on Thursday, face southeast to see the thin
crescent Moon with Antares about 12 degrees to its right.
Last easy chance to see old Moon: On Friday an hour before sunup,
look very low in SE.
If sky is very clear Saturday morning, use binoculars to scan the
horizon about 30 degrees south of east. You'll need an unobstructed
view to see the very old crescent Moon, some 27 hours before New
from lower Michigan. Southern states will have an easier view.
In mid-January each year, Altair is equally visible in west at dusk and in
east at dawn. Farther north, look for Vega and Deneb, the other two
stars of the Summer Triangle.
New Moon occurs today at 10:46 a.m. EST, as the Moon passes
narrowly and invisible north of the Sun. First chance to see the young
Moon will be early Monday evening, marking the end of the Islamic
holy fasting month of Ramadan.
Half an hour after sunset, the young crescent Moon is low in WSW,
with Venus just 5 degrees to its upper left as seen from lower Michigan.
From southern California, Moon and Venus are within 4 degrees, and
from Hawaii, within 2 degrees. The Moon's age, or time elapsed since
New, ranges from 30 hours in Maine to 37 hours in Hawaii.
In the southwest at dusk, find the 2-1/2-day-old crescent Moon with
Venus about 7 or 8 degrees to its uper left. As the sky darkens and
Venus sinks low, note the alignment of Venus, Moon, Jupiter, and
Saturn. Watch the Moon overtake Jupiter and Saturn later this week and
over the weekend.
Find the waxing crescent Moon in SW at dusk, with Venus 20 degrees
to its lower right, and Jupiter 15 degrees to Moon's upper left. Saturn is
high in southern sky, 32 degrees to Jupiter's upper left.
Here's a chance to see Jupiter in daylight: A few minutes before sunset,
locate the crescent Moon well up in SSW. From all of U.S. except
Alaska, Jupiter is 2 to 3 degrees from the Moon. Look above the Moon
from northeastern U.S., to the Moon's upper right from most of the
country, and to Moon's lower right as seen from Hawaii. If the sky is
sufficiently clear, binoculars will easily show Jupiter by the time the
Sun sets. As the sky darkens, Jupiter is prominent near the Moon.
During evening hours until they set, watch the Moon drift slowly
relative to Jupiter.
An hour after sunset, crescent Moon is in SSW. Jupiter to Moon's
lower right, and Saturn to Moon's upper left, are 32 degrees apart.
Venus is about as far to Jupiter's lower right.
The Cowboy Astronomer opens at 8:00 p.m. tonight at Abrams
Planetarium. Noted cowboy humorist Baxter Black narrates this
homespun jaunt through the night sky. The program is presented
Fridays and Saturdays at 8:00 p.m., and Sundays at 4:00 p.m. Our
family show, Rusty Rocket's Last Blast, will be presented Sundays at
2:30 p.m.
The fat crescent Moon is high in SSW an hour after sunset. Saturn is 5
or 6 degrees to Moon's upper left. Venus is very low in WSW, while
Jupiter is well up in SW, far to Moon's lower right. Tonight a line from
Venus to Jupiter, extended its own length, ends near Saturn.
Rusty Rocket's Last Blast, our family show, continues Sundays,
2:30 p.m. at Abrams Planetarium. The Cowboy Astronomer, our
feature show, is presented at 4 p.m. today. For a recorded message
on our shows, call (517) 355-4672.
Face the setting Sun, then turn 90 degrees or a quarter-turn to your left.
Lift your gaze, and you'll find the First Quarter Moon high in SSE.
Notice that the Moon's right half is illuminated. As the sky darkens,
you'll spot Saturn about 10 degrees to the Moon's right.
The slightly gibbous (more than half full) Moon is high in SSE. Note
Saturn is about 24 degrees to Moon's west (right), while the first-
magnitude reddish star Aldebaran, eye of Taurus, is about 18 degrees to
the Moon's east. Look again on Tuesday night.
At dusk the three-fourths illuminated Moon is high in SE, with the first-
magnitude reddish star Aldebaran a few degrees lower left. (From
lower Michigan an hour after sunset, Aldebaran lies 4 degrees from the
Moon.) Between them, visible in binoculars, are some stars of the
Hyades cluster. From many locations in U.S. and Canada tonight, the
Moon's leading dark edge covers or occults some Hyades stars and
Aldebaran, events best seen with a telescope. Here are times the Moon's
leading dark edge snuff out Aldebaran: In Pacific time, Vancouver
11:21 p.m.; San Francisco 11:35 p.m.; Los Angeles 11:46 p.m. In
Mountain time, Denver 12:46 a.m. In Central time, Chicago 1:50 a.m.;
Kansas City 1:51 a.m.; Austin 2:03 a.m. In Eastern time, East Lansing,
MI and Toronto, ON, 2:50 a.m.; Atlanta 2:57 a.m. Along the eastern
seaboard, the Moon reaches the star around moonset. For more
information, visit the website of the International Occultation Timing
Association:
http://www.sky.net/~robinson/iotandx.htm
An hour after sunset the Moon is in ESE with Aldebaran, eye of
Taurus, about 10 degrees upper right. Two other bright reddish stars are
nearby: Betelgeuse within 14 degrees below the Moon, and Pollux 35
degrees to Moon's lower right.
An hour after sunset, Betelgeuse is 13 degrees to Moon's right. Below
Betelgeuse are the "Dog Stars," Procyon to its lower left and Sirius to
its lower right. These three stars form the Winter Triangle, nearly
equilateral and about 26 degrees on each side.
The Moon is in east an hour after sunset, with Procyon 14 degrees to
lower right and Pollux 11 degrees left. Castor is 4-1/2 degrees above
Pollux.
About 15 to 30 minutes after sunset, the Sun and the nearly full Moon
are visible simultaneously. Look low in WSW and ENE. As sky
darkens, note the alignment, in order across the sky, of Venus-Jupiter-
Saturn-Aldebaran-Moon. Shorter alignments early this evening are
Moon-Pollux-Castor and Moon-Procyon-Sirius. The Moon sets shortly
before sunrise on Sunday. This month's second Full Moon, called a
"Blue Moon," occurs on Sunday at 11:06 a.m. EST. The deepest stage
of a penumbral lunar eclipse, visible from Hawaii and Alaska, occurs a
few minutes later, at 6:17 a.m. Hawaii time. The Moon's northern limb
will then be noticeably shaded.
The Moon, just past Full, rises in ENE soon after sunset. In WSW at
dusk at dusk, look for Venus with Jupiter 23 degrees to its upper left.
Watch the two planets evenings in February, as the gap between them
narrows by one degree daily. On February 23, the two brilliant planets
will form a striking close pair.