To the reader:
The Skywatcher's Diary for November 2003 has been prepared by
David Batch. 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 November issue, please send a long,
self-addressed stamped envelope to:
November 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/
Skywatcher's Diary: November 2003
Some evening soon, when Mars is close to due south, notice the planet's
position relative to the right (west) side of the Great Square of Pegasus. That
pattern of stars is found 30 to 40 degrees to the upper left of Mars. The bright star
Fomalhaut, that is 19 degrees (2 fists) below the planet, is aligned with the
square's west side. Currently, Mars is west of the Great Square-Fomalhaut line,
but as November progresses the planet drifts eastward. By month's end Mars will
clearly appear to the east of the line. Try to determine by nightly observation when
Mars precisely aligns with Fomalhaut and the Great Square.
The Moon is 6 degrees (12 moon diameters) to the lower right of Mars this
evening. Try to guess where the Moon will be in 24 hours, and then go out close
to the same time tomorrow night and check your estimate against the sky. Hint:
Luna will appear to the left of Mars. Both planet and Moon are among the faint
stars of the constellation Aquarius, the Water Carrier.
The difference between clock time and sundial time, known as the "Equation of
Time," reaches its maximum for the year today. A properly constructed and
mounted sundial will read almost 17 minutes faster than an accurate clock. The
reason for the discrepancy is twofold. The Earth's orbit is oval rather than circular,
so our speed around the sun varies. The Earth's rotation axis is tilted relative to
our orbit, so the angle of the sun's motion also varies throughout the year.
This evening the Moon sits near the zero point of astronomers' most frequently
used celestial coordinates: Right Ascension and Declination. That spot is
sometimes called the vernal equinox, although the connection to the seasonal
marker is obscure without some astronomy background. Others may know it as
the "first point of Aries," another ambiguous reference, since the point is in the
constellation Pisces rather than Aries. This invisible point with the confusing
names lies 5 degrees to the upper left of Luna.
Mars continues to shine noticeably bright this month, although clearly fainter
toward the end of November. Its telescopic image, unfortunately, is quickly
shrinking. The widening gap between Earth and Mars causes the disk in the
eyepiece to contract to where surface features become difficult, perhaps
impossible, unless conditions are just right. For optimum results, wait until the
planet is highest in the sky (due south) and the night air is extremely steady.
Altair, the southern most of the trio of bright stars we call the Summer Triangle, is
also the coolest of the bunch, although not by much. All three shine with a white
light, telling us they are hotter than our yellow sun. Altair's surface temperature is
13,000 degrees F while both Vega and Deneb radiate near 17,000 degrees. Altair
is the closest of its companions. The star's light takes about 17 years to arrive
here.
The second total lunar eclipse of this year occurs tomorrow evening for the
continental U.S. The eastern states will watch the Moon pass into the Earth's dark
shadow shortly after sunset and moonrise. For western U.S. observers, the Moon
rises after the eclipse has begun, and Hawaiian Islanders miss totality entirely.
Lunar eclipses vary in the color. Depending on the circumstances, the Moon can
range from a very dark gray to bright coppery orange. The color is only somewhat
predictable, so you'll need to watch the eclipse to find out what shade the Moon
takes on this time.
The Moon enters the darkest part of the Earth's shadow, called the umbra,
beginning at 6:32 p.m. EST. Totality, when the Moon is completely immersed in
the shadow, commences at 8:06 p.m. EST, and deepest eclipse occurs at 8:19
p.m. For this eclipse the length of totality is short -- only 24 minutes -- because
the Moon skims the outer edge of the umbra rather than plunging into the central
core. For more information, consult this website:
http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html.
[East Lansing sunset is 5:22 p.m.; moonrise is 5:17 p.m.
Detroit sunset is 5:18 p.m.; moonrise is 5:12 p.m.
Kalamazoo sunset is 5:28 p.m.; moonrise is 5:23 p.m.]
The Moon is Full very near the moment of deepest eclipse. The phase is defined
by the Moon's position. To be Full, it must lie exactly 180 degrees away from the
direction of the sun. Full Moon occurred last night at 8:13 p.m. EST, and the
eclipse reached maximum at 8:19 p.m. In colonial times the full moon of
November was known as the Frosty Moon or Beaver Moon. Tonight the Pleiades,
or Seven Sisters, star cluster appears 5 degrees (10 moon diameters) to the
upper left of Luna. Wait 2 hours after sunset to observe so that the Pleiades can
rise out of the lower atmosphere.
Tonight Venus passes closest to the bright star Antares, heart of Scorpius. The
two objects are 4 degrees apart. Venus is visible 30 to 45 minutes after sunset
just to the right (north) of southwest and only a few degrees above the horizon. To
see Antares too, you will need to observe from a southern state or farther south
because Antares sets too soon after sunset for mid northern and higher latitude
locations.
Mars passes a little more than a degree beneath the 4th-magnitude star Lambda
in the constellation of Aquarius. Because the star is quite faint, it will be easy to
overlook amid the glare of Mars. Use binoculars to carefully note the relative
positions of the two bodies. Look again the next 2 nights to observe how swiftly
Mars is moving compared to the background stars. Lambda lies about 400 light
years farther away than Mars.
The gibbous Moon is near Saturn over the next two nights and mornings. Tonight
you'll need to look 4 to 5 hours after sunset to give both objects time to rise. The
Moon sits 9 degrees (a fist) to the upper right of Saturn. Tomorrow night Luna
appears 6 degrees to the left and slightly below the planet. If you prefer to catch
the show in the morning, look high in the west-southwest as dawn begins. Early
tomorrow the Moon appears 6 degrees to the right of Saturn.
Tomorrow morning the Moon perches 9 degrees above Saturn and 3 degrees
below Pollux, one of the bright Gemini stars. The approach of the Moon to Pollux
is the closest pairing of Luna and any 1st- magnitude star this year. Astronomers
refer to such approaches as "appulses." Should the Moon get so close as to
cover the star, the event is called an occultation.
The Great Square of Pegasus hangs more than halfway up in the east-southeast
as dusk falls. Take a moment to carefully examine the four stars that comprise
this well-known autumn pattern. Can you put the stars in order according to
brightness? The faintest is Algenib, currently the lowest of the quartet and the only
one of the group that is 3rd magnitude. The stars to the right, Markab, and top,
Scheat, are nearly identical in brightness, just under magnitude 2.5. The brightest
is Alpheratz, on the left.
Alpheratz (al-FEE-rats), the most luminous member of the Great Square of
Pegasus, is not, technically, a part of the constellation Pegasus. It is the Alpha
star of Andromeda, the Chained Princess. But before you contemplate turning the
Square into a triangle, know that the star's name supports its placement within
the celestial steed. The name Alpheratz derives from ancient Arabic meaning
"horse's navel."
The Moon reaches Last Quarter at 11:15 p.m. EST. That is near the time it rises in
the eastern U.S. The Moon will remain visible through sunup, which means it will
interfere with the annual Leonid meteor shower. The Leonids have received
considerable attention in recent years due to activity that has been recorded as
high as thousands of meteors per hour. This year the predictions are for a more
ordinary display, on the order of a meteor every few minutes. The shower is active
over the next several mornings before the start of dawn and hits maximum
Tuesday morning.
This morning the Moon, just past Last Quarter, appears 4 degrees (8 moon
diameters) to the upper left of the star Regulus, the brightest of Leo, the Lion.
Tomorrow morning look for Luna perched 5 degrees above Jupiter and 13
degrees to the lower left of Regulus. The following morning (Wednesday) the
waning crescent hangs 11 degrees to the giant planet's lower left.
Mars continues to offer a brilliant face to earthbound observers. Look for it in the
south-southeast in early evening. Two 4th-magnitude stars in the constellation
Aquarius straddle the planet. Lambda, the brighter of the pair, sits 4 degrees (half
a fist) to Mars' right and slightly higher. Phi is on the left only 2 degrees from the
planet. Use binoculars if you have difficulty locating the stars. Mars is moving
toward Phi and passes narrowly beneath the star in a few days. Watch its nightly
progress.
Tomorrow morning before sunup the waning crescent Moon passes close to the
3rd-magnitude star Gamma in Virgo. Gamma, also known as Porrima, is a well-
known double star to amateur stargazers. The edge of the Moon just grazes the
star for observers along a line from Vancouver, BC through mid Virginia. North of
that line the star is occulted (completely covered) by the Moon. If you'd like more
specific information, check the International Occultation Timing Association's
webpage at http://www.lunar-occultations.com/iota/iotandx.htm.
[Detroit times: Disappearance 6:35 a.m. EST, Reappearance 7:10 a.m.]
A pretty sight awaits those out before dawn tomorrow. The crescent Moon, only
two days away from New, poses 4 degrees (8 moon diameters) to the upper left
of Spica, the brightest star in Virgo. There's something intrinsically attractive about
the sight of a thin crescent, and it's even more appealing when coupled with
another bright object. The pair rises just south of east about 2 1/2 hours before
sunup. They will be well positioned an hour to 1 1/2 hours later.
Tomorrow morning provides the last chance to catch the waning Moon during this
cycle. Look for it a few degrees above the east-southeastern horizon an hour
before sunrise. Luna becomes New on Sunday. That day, for observers in
Antarctica, it passes directly in front of the sun to produce a total solar eclipse.
The partial eclipse is visible only from extreme southern South America, Australia,
and New Zealand.
Today the sun enters the astrological sign of Sagittarius, that is, it passes across
the border of that section of the sky. According to astronomers, however, the sun
is positioned within the constellation of Libra. Tomorrow it crosses into Scorpius
but doesn't stay there long. Sol enters the constellation of Ophiuchus, the Serpent
Charmer, on the 30th of this month. Not until December 18 does the sun move
into the constellation of Sagittarius.
The Moon is New at 5:59 p.m. EST. The Moon also reaches perigee (Moon
closest to Earth) within minutes of that time. Furthermore, this is the closest
perigee of the year -- 221,712 miles separate us. Normally the highest tides
occur each month near New and Full Moon when the tidal effects of the Moon and
sun join together. Add in the closest perigee and today we have the potential for
the highest tides of the year.
If you are up for a challenge, the young Moon, just under 24 hours old, can be
sighted shortly after sunset. You will need a flat southwestern horizon and a
crystal clear sky. Timing is also critical. Fifteen minutes after sunset the hairline
crescent sits 2 degrees above the horizon, 9 degrees to the north (right) of
southwest. Bright Venus will be easiest to spot, 11 degrees (a fist) above the
southwest. Eight degrees to the planet's lower right sits Mercury, fainter than
Venus but respectable. The Moon is 3 degrees to the lower right of Mercury. Bring
binoculars.
The Moon and Venus make a lovely couple this evening. The pair hangs low in
the southwest as dusk settles in. The Moon is considerably easier to spot than it
was last night. Thirty minutes after sunset Venus perches 9 degrees above the
horizon and 3 degrees (6 moon diameters) to the upper right of Luna. Add some
twilight colors, toss in a few clouds to intensify the hues and the scene screams
photo opportunity!
Luna continues to grow and climb higher as it waxes its way through the evening
skies. An hour after sunset, the Moon perches 21 degrees (2 fists) above the
south-southwest. Tonight it sits among the stars of Sagittarius, near the "handle"
of the teapot figure. That distinctive shape lies to the lower right of the Moon.
Tomorrow night Luna creeps across the border into Capricornus, one of the
fainter zodiac constellations.
One of the enduring icons of Thanksgiving is the Cornucopia, or Horn of Plenty,
brimming over with the harvest bounty. This symbol also has a link with the sky. In
ancient Greek legends it was associated both with Capella, the bright star in the
northeast at the end of dusk, and the constellation Capricornus, near the Moon
tonight. The word Capella is the diminutive form of Capra, or female goat. In one
legend it is said to represent a piece of the goat's horn broken off by Zeus. He
turned it into a sign of prosperity and placed it in the sky. In another version the
horn was transformed into Capricornus.
Saturn is beginning to make a statement in the evening sky. It rises about 2 1/2
hours after sunset, so it's nicely placed before midnight. The planet is still
relatively close to Earth and its rings are broadly tilted (25 degrees) toward us,
making it an entrancing sight in the telescope. The planet continues to climb
higher as the weeks pass, but the weather becomes more bothersome, at least
for many locales. All in all, now is an excellent time to observe the Ringed Planet.
Can you view Mars and Jupiter simultaneously? Jupiter rises just before Mars
sets, thereby creating a window of less than 25 minutes when both planets can
be seen. If you wish to accept the challenge, find an observing site with
unobstructed views to the east and west. The event occurs after local midnight,
but since timing is critical, determine exactly when Jupiter rises and Mars sets for
your location. Any of the many astronomy programs for home computers should
give precise enough times. Or find an interactive version on the web such as
MICA found at http://aa.usno.navy.mil/.
The Moon reaches First Quarter phase at 12:16 p.m. EST, so by tonight it should
appear slightly more than half full. Mars perches 11 degrees (a fist) to the upper
left of Luna. If your calendar displays lunar phases, it may proclaim two First
Quarter Moons in November 2003. Most commercial calendars use Greenwich,
England, to calculate moon phase timings. Such reckoning produces two First
Quarters this month. But from the Eastern Time Zone, the November 1 First
Quarter Moon actually occurred at 11:25 p.m. on October 31.
Please send any comments, suggestions, or questions to
Thomas G. Ferguson:
fergus52@msu.edu
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