Abrams Planetarium
SKYWATCHER'S DIARY: October 1997
To the reader
The Skywatcher's Diary for October 1997 has been prepared
by Robert C. Victor. Sometimes you can see next month's in advance by looking in our archives. Credit to Abrams
Planetarium, Department of Physics and Astronomy at
Michigan State University, together with
mention of our Sky
Calendar,
would be appreciated.
A sample issue of Sky Calendar from a previous month is available
over the Internet. It can be viewed via a World-Wide Web browser such as
Netscape or Internet Explorer, directly at URL:
http://www.pa.msu.edu/abrams/apr97skycal.html
If you would like a printed sample of the October issue, send a long,
self-addressed stamped envelope to:
October Sky Calendar
Abrams Planetarium
Michigan State University
East Lansing, MI 48824
Each month, the Department of Physics and Astronomy at Michigan State
University also makes Skywatcher's Diary available over the Internet.
It can be accessed via a World-Wide Web browser such as Netscape or Internet Explorer,
directly at URL:
http://www.pa.msu.edu/abrams/diary.html
The Skywatcher's Diary is also available via anonymous ftp at:
www.pa.msu.edu in the directory /pub/swd
ftp://www.pa.msu.edu/pub/swd/
Planet Panorama at Dusk: Venus, of mag. -4.4 to -4.6, is brilliant
evening "star" low in SW to SSW at dusk. Mars, mag. +1.1, or 160-
200 times fainter than Venus, lingers nearby all month. It's 3 degrees
upper right of Venus on Nov. 1, 6 deg to Venus' lower right on Nov.
17, and nearly 7 deg to Venus' lower right Nov. 23-Dec. 1. Bright
Jupiter gleams in Capricornus, well up in southern sky at dusk; at mag.
-2.4 to -2.2, it ranks next in brightness after Venus. Jupiter is upper left
of Venus, by 47 deg on Nov. 1, 24 deg on Nov. 30. Saturn at dusk
gains altitude in E to ESE as month progresses. This "star" of mag.
+0.3 to +0.5 is in Pisces, about 60 deg E of Jupiter. Note these two
giant planets can be found by extending the diagonals of the Great
Square of Pegasus, 16 deg SE to Saturn, and 44 to 42 deg SW to
Jupiter. Late in month, use binoculars to find zero-magnitude Mercury
very low in SW twilight glow, far to Venus' lower right. Viewers in S
states are favored for seeing Mercury with unaided eye. Mercury-Venus
stay 23 deg apart Nov. 27-Dec. 5. Uranus is within easy reach of
binoculars at nightfall, when Moon is not too bright. Look 8-11 deg W
of Jupiter and just over 1 deg S of 6th-mag. Omicron Capricorni,
lowest star in compact triangle just below Alpha and Beta Capricorni.
See the Uranus finder chart on our Sky Calendar in box for Nov. 6-8.
The Moon passes bright evening planets on Nov. 3, 4, 7, and 11. On
Nov. 11, Moon occults (covers) Saturn after sunset from S. Texas, Gulf
Coast, Southern and Southeast U.S., Mid-Atlantic Coast to Delmarva
peninsula and S. New Jersey, and Cape Cod. The northern limit of the
occultation, where Saturn appears to graze the Moon's north polar
region, crosses the following states: TX, LA, MS, AL, GA, NC, VA,
MD, DE, NJ, MA. From places northwest of that line, the Moon
appears to pass south of Saturn, and quite narrowly as seen from the
cities of Austin TX, Jackson MS, Washington DC, Philadelphia, New
York City, and Boston. Binoculars may suffice to show Saturn during a
narrow miss, but a telescope is needed to see disappearance and
reappearance at edge of the bright nearly full Moon-- here are times of
the occultation for selected cities -- CST: Houston 5:35-5:50 pm; New
Orleans 5:34-6:02 pm; Mobile 5:37-6:05 pm. EST: Miami 6:24-7:23
pm; Tampa 6:29-7:19 pm; Charleston SC 6:45-7:23 pm; Charlotte NC
6:57-7:16 pm; Richmond VA 7:08-7:21 pm. For map of N limit, see
Jan '97 Sky & Telescope, p 90. More information:
http://www.sky.net/~robinson/iotandx.htm
Leonid meteors may arrive in greater numbers than usual this year on
the morning of Nov. 17, despite bright moonlight. Observers in western
U.S., Alaska, and Hawaii are most likely to see the best display. For
more information, see Nov. 16 in the Diary below, Sky & Telescope
Nov. 1995 pp. 24-34; Nov. 1996 pp. 72-74; Nov. 1997 pp. 102-104;
January 1967, pp. 4-10 (on the meteor storm of Nov. 17, 1966); and the
websites: http://www.skypub.com/meteors/meteors.shtml
http://medicine.wustl.edu/~kronkg/leonids.html
http://www.skypub.com/meteors/leo97a.html
Skywatcher's Diary: November 1997
-
- The young Moon is easy to see from mainland U.S. tonight, but folks
in northern states need to look early! Half an hour after sunset, the thin
crescent is very low in WSW, about 30 degrees lower right of Venus.
As sky darkens, note Mars 3 degrees to Venus' upper right, bright
Jupiter approaching its high point in south, and Saturn climbing in ESE.
-
- The two brightest evening objects are low in SW at dusk: Moon with
Venus about 20 degrees to its left. Using binoculars, can you still see
Antares 9 degrees to Moon's lower left? Viewers in southern states
should see it easily. Look about 40 minutes after sunset.
-
- An hour after sunset, Moon is in SW, with brilliant Venus about 10
degrees to its lower left. Faint Mars is within 3-1/2 degrees upper right
of Venus.
-
- Low in SW about an hour after sunset, look 10 degrees below the
crescent Moon for brilliant Venus and faint Mars, still 4 degrees apart.
-
- This evening and Thursday, Venus stands near greatest elongation, 47
degrees from Sun. As seen from Earth, Venus now appears at its
farthest angular distance from the Sun during the planet's current reign
as "evening star." But Venus is now also farther south than it will be
again until November 2005, so it appears far to the left of the setting
Sun instead of high above it. Venus will take another month until it
reaches its highest position in the sunset sky, and will set some three
hours after the Sun in early December.
-
- An hour after sunset, Venus gleams low in SW with Mars 4 degrees to
its left, while in the southern sky Jupiter shines 12 degrees left of the fat
crescent Moon.
For the rest of Venus' evening appearance, the planet will be fascinating
to watch through telescopes and binoculars. Observe Venus in daylight
or right around sunset, before the glare of the brilliant planet against the
darkening sky becomes too great. Watch for changes in Venus' phase
until it disappears in the second week of January. Venus now appears
about half full, and will become a large thin crescent as it approaches
Earth and swings almost in front of the Sun. As weeks pass, the
crescent will become large enough to resolve even with 7-power
binoculars.
-
- Face the Sun as it is about to set in WSW, and you'll find the First
Quarter Moon in SSE, over your left shoulder, 90 degrees, or one-
quarter circle, from the Sun. Note Moon is half illuminated, with the
terminator (day-night boundary) appearing as a vertical line dividing the
Moon's disk into a lighted and a dark half. This is the ideal phase for
using binoculars or a small telescope to study lunar surface features.
Even before the Sun sets, try to spot Jupiter 3 or 4 degrees to Moon's
lower right. It'll be easy to see Jupiter as twilight deepens.
-
- An hour after sunset, Jupiter is in south, within 17 degrees lower right
of the waxing gibbous Moon.
-
- As darkness falls, binoculars and perhaps naked eye show the 4th-
magnitude star Theta in Capricornus one-third of a degrees (20 arc
minutes) to Jupiter's upper right. The same distance to Jupiter's east
(upper left) tonight is a 6th-mag. star, SAO164156. Jupiter's four bright
moons are much closer in, three on the same side as the latter star. The
brightest one, appearing farthest out tonight and easiest to see, is 5th-
mag. Ganymede. Jupiter is moving eastward by 7 arcminutes per day,
and on Wednesday evening will occult or cover the 6th-mag. star. For
details, see IOTA's website at
http://www.sky.net/~robinson/iotandx.htm
-
- At nightfall, the waxing gibbous Moon is in SE, three-quarters of the
way from Jupiter in S toward in ESE. Binoculars show Jupiter has
closed its distance from the 6th-mag. star to its upper left to 14
arcminutes (less than one-quarter of a degree). Observe the planets
nightly and watch for changes.
-
- Seen from lower Michigan, the Moon creeps closely below Saturn
shortly after 7:15 p.m. EST. Using binoculars or a telescope, beginning
around sunset, observe every 15 minutes and watch the Moon's north
polar regions slip past the planet. From southern and eastern parts of the
U.S., the Moon actually occults or covers Saturn; see information
above.
Other sights for binoculars this evening: Mars is now 5 degrees lower
right of Venus. The 3rd-mag. star Lambda, top of the Teapot of
Sagittarius, is 1.5 degrees upper right of Venus. Note stars 3rd-mag.
Phi and 2nd-mag. Sigma 4 degrees and 6 degrees upper left of Venus
tonight. Venus is moving nearly 1 degree per day, and will pass near
these stars Nov. 15 and 17. Look for a 6th-mag. star 7 arcminutes upper
left of Jupiter. Two satellites, Ganymede and Callisto, form a close pair
3 arcminutes to Jupiter's lower right.
-
- The Moon is in E at dusk with Saturn about 14 degrees upper right. See
how far the Moon has moved in 24 hours! Three of Jupiter's moons are
within easy reach of binoculars tonight. To Jupiter's west (lower right)
are Ganymede and Callisto, and to the planet's east is Europa. Through
a telescope, Io becomes visible as it passes off the west edge of Jupiter's
disk at 6:00 p.m. EST, and Io's shadow is a tiny black dot on Jupiter
until 7:19 p.m. A 6th-mag. star disappears behind Jupiter's east limb
tonight and reappears at the west limb over two hours later.
Approximate times of disappearance, to within a minute or two in each
time zone are: 5:54 p.m. PST; 6:56 p.m. MST; 7:58 CST. From mid-
lower Michigan the star disappears around 8:59 p.m. EST, but there
Jupiter is only about 20 degrees up in SW. For more information, visit
the IOTA website at http://www.sky.net/~robinson/iotandx.htm
-
- If you have an unobstructed view toward WSW and ENE, try to view
the setting Sun and rising Moon simultaneously this evening. The
Moon is nearly Full. Starting Saturday morning, it will be possible to
see Sun and Moon simultaneously just after sunrise.
-
- The Moon passed Full this morning, and rises in ENE within 40
minutes after sunset this evening as seen from lower Michigan. Two
hours after sunset, look 10 degrees upper left of the "Frosty Moon" for
the compact Pleiades star cluster, and a similar distance to Moon's lower
left for bright Aldebaran, the "follower" of the Pleiades. Watch the
Moon creep closer to Aldebaran until dawn on Saturday, when they're 5
degrees apart.
-
- An hour after sunset, brilliant Venus and dim Mars are still within 6
degrees apart low in SW. Binoculars show each planet has a 3rd-mag.
"companion star"; one is 0.4 degree below Venus, and the other is 1.5
degrees to Mars' left. Look nightly and watch for changes. Within
another half hour, Moon rises in ENE. Can you spot Aldebaran 3
degrees to Moon's upper right? For the rest of the night, Moon will pull
away from the star. By dawn on Sunday, they'll be over 8 degrees apart.
-
- Tonight and Monday are the northernmost moonrises for November.
>From lower Michigan tonight, the Moon rises about 2-1/4 hours after
sunset. By four hours after sunset and for rest of night, Betelgeuse,
shoulder of Orion, is within 11 degrees south of Moon.
Bright moonlight reduces visibility of Monday morning's Leonid
meteor shower. But getting up to view the shower in Monday's
predawn darkness hours could still be worthwhile. That's because for
the last few years, the strength of this annual shower has increased with
the approach of its parent body, Comet Tempel-Tuttle. On Nov. 17
around 7:40 a.m. EST (5:40 a.m. MST, 4:40 a.m. PST, 2:40 a.m.
Hawaii time), our planet Earth crosses through the comet's orbital plane,
only 108 days before the comet itself, in its 33-year orbit, passes the
same point a scant three-quarters of a million miles closer to the Sun.
As we cross the comet's orbit plane on Nov. 17, it's sunrise from
Michigan to Louisiana, while predawn darkness prevails from Montana
to Arizona and places farther west. If Earth encounters the most
meteoroids then, the shower will be seen best from western U.S.,
western Canada, Alaska, and Hawaii. But if the shower is strongest a
few hours earlier, then more of eastern U.S. could see the show. If and
when a very strong shower occurs, it is likely to last no more than an
hour, and would be seen wherever the Sickle of Leo is visible, where
local time is between midnight and dawn. Meteors could be seen
anywhere in the sky, but the radiant of the shower (direction from
which the meteors approach Earth) is within the Sickle, about 10
degrees north of the star Regulus.
Tempel-Tuttle itself is a minor comet, probably getting no brighter than
8th magnitude when it passes within 34 million miles of Earth next
January. The real spectacle, a possible meteor storm, may come on
November 17, 1998, when Earth encounters particles following the
comet by 257 days, or even a year later, in Nov. 1999. A Leonid storm
with over 100,000 meteors per hour was observed over western U.S.
on November 17, 1966. For observers' accounts, see the January 1967
issue of Sky & Telescope, pp. 4-10.
No one expects such large number of meteors this year. But just in case
something unusual happens, many amateur astronomers will be
checking the sky between midnight and dawn Monday morning. If you
can't cover the whole interval yourself, why not organize a cooperative
effort where each observer covers an hour, activating a phone tree to
contact the others if something spectacular unfolds?
For more on the Leonids, visit the websites listed just before the Diary
entry for Nov. 1.
-
- An hour after sunset, brilliant Venus and faint Mars are 6 degrees apart
low in SW. Binoculars show 3rd-magnitude Lamdbda Sagittarii within
1 degree below Mars, and 2nd-mag. Sigma within 0.3 degree upper left
of Venus.
-
- An hour before sunrise on Wednesday, the waning gibbous Moon is
high in SW, with Procyon, the Little Dog Star, 12 degrees lower left,
and Pollux, the brighter Gemini twin, 12 degrees upper right. The
prominent object 26 degrees below Procyon is Sirius, the Dog Star,
brightest star in the night sky.
-
- Now that Moon rises in late evening (about 5 hours after sunset), there
are over 3 hours of dark-sky viewing after twilight fades. Enjoy the
Milky Way, Andromeda Galaxy, and other deep-sky objects. If your
sky is too bright to see the Milky Way and would like to find out what
you can do, visit the website of the International Dark-sky Association
at: http://www.darksky.org/~ida/index.html
-
- Venus-Jupiter are now 30 degrees apart in SW to S at dusk. In a month
they'll be 17 degrees apart. An hour before sunup Friday, the Moon,
approaching Last Quarter, is high in S, with Regulus, heart of Leo, 7
degrees left. Note Moon's shape is just over half full.
-
- The Pleiades star cluster is at opposition to Sun tonight: Low in ENE at
dusk, high in S in middle of night, and low in WNW at dawn. Regulus
is high in S an hour before sunrise, about 6 degrees to Moon's upper
right on Saturday morning. Note Moon is a fat crescent, just under half
full.
-
- Although we're already two months into autumn, the Summer Triangle
can still be followed evenings until mid-January. An hour after sunset,
look for Vega, its brightest member, in the west more than halfway to
overhead. Deneb is just west of overhead, and Altair is halfway up in
SW. Far outshining these stars are Venus and Jupiter, nearly 30 degrees
apart, to the Triangle's lower left.
-
- Have you se