To the reader:
The Skywatcher's Diary for February 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 February issue, please send a long,
self-addressed stamped envelope to:
February 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/
Venus, Jupiter, and Saturn are visible at dusk in all of February. After midmonth, Mercury joins them, raising the total to four planets. Not until April-May 2002 will a greater number of naked-eye planets (all five) be simultaneously visible.
Venus, the most brilliant, is low in WSW to W at dusk and sets soon
after dark. Bright Jupiter on Feb. 1 is 22 degrees upper left of Venus.
The gap between these two brightest planets closes by 1 degree per day,
to 20 degrees on Feb. 3, to 15 degrees on Feb. 8, to 10 degrees on Feb.
13, and to 5 degrees on Feb. 18. Don't miss the spectacle on Feb. 23, as
Venus passes very closely upper right of Jupiter! After Feb. 23, the
Venus-Jupiter separation widens by a degree per day, to 5 degrees by
Feb. 28. Saturn is high in SSW to WSW at dusk, 30 to 26 degrees
upper left of Jupiter. On Feb. 28 Saturn is 21 degrees upper left of
Venus. Very young Moon Tues. Feb. 16: See Skywatcher's Diary,
below. In the rest of that week (Feb. 17-20), waxing crescent Moon
climbs past all four evening planets. Mercury gets higher and easier
nightly after Feb. 16; look 12 degrees lower right of Venus-Jupiter pair
on Feb. 23, closing to 6 degrees lower right of Jupiter and 11 degrees
lower right of Venus on Feb. 28.
Morning Planet: Brightening Mars rises in ESE before middle of
night Feb. 1 and 15-20 minutes earlier each week. At dawn Mars is in
SSW, 10 to 17 degrees E of Spica.
Skywatcher's Diary: February 1999
The Moon, over a day past Full, rises in ENE about 1 hour 20 minutes
after sunset as seen from lower Michigan. From northeastern U.S. and
eastern Canada, the Moon covers the star Regulus in early evening. From Boston,
a telescope shows the star emerging along the Moon's
dark edge at 7:04 p.m. EST; from Montreal, at 7:00 p.m. Elsewhere,
use binoculars to see Regulus just above the rising Moon, and watch
them separate by half a degree (about one Moon's width) per hour. By
an hour before sunup on Tuesday, they're in the west, 5 degrees apart as
seen from Michigan, with Regulus to Moon's lower right.
>From latitude of Boston and East Lansing MI westward across the
U.S., the Moon rises within 2-1/2 hours after sunset tonight, and about
an hour later each night for the rest of this week. The sky is moonless at
nightfall through Feb. 16, and at very dark sites the zodiacal light
appears as a huge, nearly vertical cone of dim light in WSW. How far
from the Sun can you detect its glow? Venus, just above the WSW
horizon at nightfall, is 23 degrees from Sun, and Jupiter is now 44
degrees from Sun. From a fantastically dark site, you may be able to
trace the zodiacal light even past Saturn, now 74 degrees from Sun. For
more on this phenomenon, see
http://antwrp.gsfc.nasa.gov/apod/ap970826.html
An hour after sunset, Venus is low in WSW, with Jupiter 20 degrees to
upper left. Keep watch as they get one degree closer daily. Saturn is
now 30 degrees upper left of Jupiter.
The brightest minor planet, Vesta, at opposition tonight, is easy to
locate
in binoculars as a "star" of mag. 6.2, just 6.5 degrees WSW of 3.0-
mag. Epsilon Leonis, the star at the tip of the Sickle of Leo. On our
Sky Calendar diagram for Feb. 3, note that a line from Epsilon to 4.3-
mag. Lambda Leonis, 3.3 degrees long, extended nearly as far past
Lambda, ends at Vesta. A detailed Vesta finder chart appears on p. 112
of Feb. Sky & Telescope.
Tonight the Moon rises due east within 4-1/2 hours after sunset from
northern U.S., and about 4 hours after sunset from southern U.S. By
an hour before sunrise on Friday, the Moon is in SW, with Spica 12
degrees lower left and Mars 21 degrees left. Mars and Spica are now 11
degrees apart.
The Cowboy Astronomer is presented 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 p.m. Our family
show, Rusty Rocket's Last Blast, is presented Sundays at 2:30 p.m.
Six hours after sunset, Moon is low in E to ESE, with Spica 6 degrees
lower right. Within another hour, Mars is in ESE, 11 degrees lower left
of Moon and Spica. By an hour before sunup on Saturday, the trio is in
SSW, with Spica now 6 degrees below the Moon and Mars 9 degrees
to the Moon's left.
An hour before sunup on Sunday, Mars is in SSW, with the waning
gibbous Moon 3 or 4 degrees to its upper left.
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.
An hour before sunup on Monday, Moon is in the south, with Mars
about 15 degrees to its right. The half-illuminated Moon is at Last
Quarter phase, 90 degrees or one-quarter of a circle to the west of the
Sun. Follow the Moon until about four hours after sunrise.
An hour after sunset, three planets are in a line nearly 45 degrees long.
Brilliant Venus is low in WSW, with bright Jupiter 15 degrees to its
upper left. Watch the gap Venus-Jupiter close by one degree daily until
Feb. 23. Saturn is now 29 degrees to Jupiter's upper left.
On Tuesday 1-1/2 hours before sunup, the fat crescent Moon is in SSE.
The reddish first-magnitude star Antares, heart of Scorpius, is about 12
degrees to Moon's lower left. The Scorpion's head is marked by three
stars in a nearly vertical line, 4 to 10 degrees below the Moon. Mars and
Spica are 12 degrees apart in SSW.
An hour before sunup on Wednesday, the waning crescent Moon, one-
third full, is in SSE, with reddish twinkling Antares, "rival of Mars," 9
degrees to its lower right. Mars itself is in SSW, shining with a steady
light.
In WSW an hour after sunset, Jupiter is 13 degrees upper left of Venus.
Using binoculars, how many satellites of Jupiter can you observe?
Tonight Ganymede and Callisto appear farthest from Jupiter and are
easy to spot as faint "stars" on opposite sides of the planet. In order
from upper left to lower right, tonight's arrangement of Jupiter and its
four Galilean moons is: Ganymede, Europa, Jupiter, Io, Callisto. Note
the line connecting Jupiter and its moons points downward toward
Venus and upward toward Saturn.
About 1-1/2 hours before sunrise on Friday, the crescent Moon is in
SE, with the Teapot of Sagittarius rising below and lower right.
Antares, heart of the Scorpion, is in SSE, and the Summer Triangle,
consisting of Vega, Altair, and Deneb, is in E to NE. All these stars rise
about 2 hours earlier with each passing month, and by mid-June will be
in these same places in the early evening.
At nightfall in mid-February, the Milky Way passes nearly overhead.
Follow its course from Cygnus low in NW, upward through Cepheus
and Cassiopeia, through Perseus and Auriga nearly overhead, then
down past the horns of Taurus and feet of Gemini and through the
Winter Triangle in the SE. The Milky Way of winter is more subtle and
less bright than its summer counterpart, because as we look up toward
the horns of Taurus, we are facing away from the bright center of our
Galaxy. If you have trouble seeing the zodiacal light or the Milky Way
despite clear skies, your problem may be light pollution. For
information, see the webpage of the International Dark-Sky Association
at:
http://www.darksky.org/~ida/index.html
An hour before sunrise on Saturday, the thin crescent Moon is very low
in SE.
An hour after sunset, Venus is in WSW, with Jupiter 10 degrees to its
upper left. Only ten days to go until a spectacular close pairing of these
two brightest planets! Until then, watch them get one degree closer each
day.
About 45 minutes before sunrise on Sunday, the thin old crescent Moon
is just above horizon in ESE. A line from Vega to Altair, extended,
points toward the rising Moon.
The seven brightest objects visible an hour after sunset, in order, are:
Venus and Jupiter, 9 degrees apart in WSW; Sirius in SE; Capella, just
ENE of overhead; Rigel in SSE; Procyon in ESE; and Saturn in SW, to
upper left of Venus and Jupiter.
The Moon is New tonight at 10:39 p.m. PST (1:39 a.m. EST on
Tuesday morning).
Can you spot the very young Moon? In WSW shortly after sunset,
Jupiter is 7 degrees upper left of Venus, and Mercury is 16 degrees
lower right of Venus; the young Moon is below Mercury, by 2 to 3
degrees from E Coast, 1 degree from W Coast. Use binoculars for
Mercury and Moon. Twenty minutes after sunset, the very thin Moon is
16 hours past New from Boston, 17 hours old from Miami, and an
easier 19 hours old from W Coast. From Hawaii, the 22-hour Moon
has climbed just above Mercury and may be glimpsed with unaided
eye. Who will be the first to see the young Moon, using binoculars?
Who will be the first to spot it with unaided eye?
About half an hour after sunset, the crescent Moon is easy to see in
WSW, with Venus 5 or 6 degrees above, and Jupiter 6 degrees upper
left of Venus. Mercury is 15 degrees lower right of Venus and about 10
degrees lower right of the Moon. As the sky darkens, look for Saturn
28 degrees upper left of Jupiter. Watch the Moon climb above three
more planets by the end of this week. Note the bluish earthshine on the
Moon's dark side.
With only 5 days remaining until their spectacular pairing, Venus and
Jupiter are just 5 degrees apart in WSW at dusk, not far to Moon's
lower right. Mercury is 15 degrees to Venus' lower right. Saturn is
about 25 degrees to Moon's upper left.
Venus and Jupiter are just 4 degrees apart in WSW at dusk, far to
Moon's lower right. Mercury is about 14 degrees to Venus' lower right.
Saturn is about 10 or 11 degrees above Moon or to its upper left. Moon
and four planets (Mercury to Saturn) span 46 degrees.
Moon is high in SW at dusk, with Saturn about 5 degrees to its lower
right. Far below, in WSW, Jupiter is within 3 degrees to upper left of
Venus, and Mercury is within 14 degrees to Venus' lower right. Only
three days to go until the spectacular close pairing of Venus and Jupiter.
Look nightly!
Venus-Jupiter are within 2 degrees apart in WSW at dusk and can be
followed for over two hours after sunset. Mercury at dusk is 13 degrees
to Venus' lower right, while Saturn is 27 degrees to Jupiter's upper left
and 19 degrees to Moon's lower right. From highest to lowest, the five
solar system bodies visible are Moon, Saturn, Jupiter, Venus, Mercury.
By this evening Venus climbs to within 0.8 degree lower right of
Jupiter. Look again Tuesday evening! Mercury at dusk is about 13
degrees lower right of the brilliant duo -- this week and next are the best
of this year for seeing this elusive planet in the evening sky. Saturn lies
just over twice as far to the pair's upper left. The Moon is at First
Quarter phase, half full and high is SSW at dusk. Bright Aldebaran, eye
of the Bull, and the nearby stars of the Hyades cluster, lie within 7 or 8
degrees to the Moon's upper left.
Don't miss tonight's spectacle, as Venus passes very closely upper right
of Jupiter! Can you spot one or both planets before sunset? Their
separation at dusk is 0.2 degree from East Coast, 0.3 degree from West
Coast, 0.4 degree from Hawaii. Saturn is 27 deg. upper left of the close
pair, while Mercury is 12 degrees to the pair's lower right. After tonight,
Venus-Jupiter separation widens by 1 degree per day, to 5 degrees by
Feb. 28.
Venus is now about 1.2 degrees above Jupiter, in WSW to W at dusk.
Each evening, at the same stage of twilight, Jupiter appears lower, and
Venus a little higher. At dusk, Mercury is within 11 degrees lower right
of Jupiter, and Saturn is 26 degrees upper left of Venus. Moon is in SE,
with the red supergiant star Beteleguse 12 degrees to Moon's lower
right.
Tonight brilliant Venus is just over 2 degrees above Jupiter, in WSW to
W at dusk. Watch these two planets spread one degree farther apart with
each passing day. Saturn is 25 degrees to Venus' upper left, Mercury
less than half as far to Venus' lower right. The Moon is in ESE to SE,
with the Gemini twins, Castor above Pollux, to the Moon's left, and
Procyon below the Moon. Betelgeuse, Procyon, and brilliant twinkling
Sirius, the "Dog Star" 36 degrees to Moon's lower right, form the
nearly equilateral Winter Triangle.
Moon is in ESE at dusk. Pollux and Castor, the Gemini twins, are
about 11 and 15 degrees to Moon's upper left. Procyon is 14 degrees to
Moon's lower right. Sirius, brightest nighttime star, is 26 degrees lower
right of Procyon. Even brighter than Sirius, the planets Venus and
Jupiter are just over 3 degrees apart in WSW to W. Saturn is 24 degrees
upper left of Venus; tonight through March 2, Mercury stays 11 degrees
to Venus' lower right.
Brilliant Venus is in WSW to W at dusk, with Jupiter 4 degrees to its
lower right. Mercury is 7 degrees to Jupiter's lower right. Saturn is
about 22 degrees to Venus' upper left.
Low in WSW to W at dusk, Jupiter and Mercury are 5 and 11 degrees
to lower right of brilliant Venus. This is as close as Mercury gets to
Venus during this evening apparition, but on March 5 Mercury-Jupiter
will be only 4 degrees apart.
At dusk in eastern U.S. tonight, Regulus appears about 4 degrees to
lower left of the nearly Full Moon. The Moon will pass just south of
Regulus early Monday morning, around 2 a.m. PST from West Coast,
5:30 a.m. EST from East. Narrowest miss occurs in southern
California. Use binoculars or a telescope to see the 1.4-mag. star in the
Moon's bright glare. Seen from Hawaii, the Moon covers the star
tonight; in Honolulu, a telescope shows star's disappearance at 10:42
p.m. and reappearance at 12:03 a.m. Hawaii time.