To the reader
The Skywatcher's Diary for June 1998 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 recent issue of the Sky Calendar is available
over the Internet. It can be viewed via a World-Wide Web browser at
http://www.pa.msu.edu/abrams/SkyCalendar/Index.html
If you would like a printed sample of the June issue, send a long,
self-addressed stamped envelope to:
June 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 with a World-Wide Web browser at
http://www.pa.msu.edu/abrams/SWD/Diary.html
The Skywatcher's Diary is also available via anonymous ftp at:
ftp://www.pa.msu.edu/pub/swd/
Three bright planets are in view one to 1-1/2 hours before sunrise.
Begin with Venus, brightest "star" in morning sky, low in E to ENE.
Jupiter, next in brilliance, on June 1st is in ESE, 38 degrees (about four
fists, assuming a 10-degree fist) to upper right of Venus. By June 30th
Jupiter climbs well up in SE, and its distance upper right of Venus has
increased to 69 degrees (seven fists). See June 3 in Skywatcher's Diary
for some tips on angular measure. Saturn on June 1st is low in E,
within 4 degrees (less than half a fist) upper right of Venus. Saturn
climbs toward the ESE as this month progresses, and by June 30th,
Saturn increases to 35 degrees (3-1/2 fists) upper right of Venus.
Throughout June, Saturn remains 34 degrees (3-1/2 fists) lower left of
Jupiter, as both planets climb higher and leave Venus near the horizon.
That's as close as the two giant planets appear to get to each other in
1998. From May 28 until July 19, for the first time since 1982, Jupiter
and Saturn appear within a single constellation (Pisces). In the year
2000, for the first time since 1981, Jupiter will finally overtake Saturn.
Mercury is the only evening planet; see June 15, 21, 24-28, 30 in
Skywatcher's Diary.
The Moon passes four bright planets; see June 15-20, 24, 25 in
Skywatcher's Diary.
SKYWATCHER'S DIARY: JUNE 1998
As you watch the Sun set in WNW this evening, the First Quarter
Moon will be over your left shoulder, in SSW, 90 degrees or one-
quarter circle from the Sun. Note the Moon's right half, the side toward
the Sun, is illuminated. As darkness falls, the first-magnitude star
Regulus, heart of Leo the Lion, is about 12 degrees to Moon's lower
right.
An hour before sunrise on June mornings, the two brightest "stars" are
Venus, very low between east and ENE, and Jupiter, in ESE to SE, far
to Venus' upper right. On Wednesday morning they are 40 degrees
apart. Fainter Saturn is 6 degrees upper right of Venus on Wednesday
and one degree farther from it each day.
An hour after sunset these evenings, The two brightest stars visible are
yellow-orange Arcturus, high in SE to SSE, and blue-white Vega, in
ENE. These two stars are 59 degrees apart. A clenched fist, held with
your arm fully extended, is "handy" for measuring angular distances
across the sky. On a clear starry night, calibrate your own fist by
counting how many times its width is needed to span the distance from
the horizon to overhead. If your fist must be positioned nine times to
cover that 90-degree arc, then your fist would take up 10 degrees of sky.
Through the night, watch Vega follow Arcturus across the sky, the two
stars remaining about 6 fists apart.
First-magnitude Spica, marking the spike of wheat in the hand of Virgo,
is in the southern sky at dusk in early June. Tonight, look about 8
degrees lower left of the waxing gibbous Moon. Crossing due south 50
minutes after Spica and 30 degrees higher is zero-magnitude Arcturus,
brightest star in the current evening sky. Arcturus-Spica are 33 degrees
apart.
In the southern sky at dusk, locate Spica about 8 degrees to Moon's
lower right.
Milky Way Legacy continues 8:00 p.m. tonight at Abrams Planetarium.
Tour our amazing home galaxy with noted author Ken Croswell and
emerge with a clearer view of our home in space. Find out some of the
ways the Milky Way is very special, and how, unlike most galaxies, it
is equipped to create the variety of ingredients needed for life.
Showtimes are Fridays and Saturdays at 8 p.m., Sundays at 4 p.m.,
through August 2.
An hour before sunup on Sunday, locate Saturn in the east, 10 degrees
to upper right of brilliant Venus and 34 degrees to lower left of bright
Jupiter.
Our family show, WSKY ... Radio Station of the Stars, is presented
Sundays, 2:30 p.m. at Abrams Planetarium, through August 2.
Venus and Jupiter are 45 degrees apart in E to SE 45 minutes before
sunup on Monday. They'll remain the two brightest "stars" in morning
twilight until September, but will continue to spread apart, appearing on
opposite sides of the sky by the end of summer.
Just one night before Full, the Moon is in SE an hour after sunset
tonight. Note the first-magnitude reddish star Antares, heart of
Scorpius, about 9 degrees to the Moon's lower right. Moon and star
remain about the same distance apart for most of the night. By 1-1/2
hours before sunup on Tuesday, They're in SW. with Antares to
Moon's lower left.
Tonight's Full Moon is up all night, rising in ESE before sunset on
Tuesday and setting in WSW soon after sunrise on Wednesday. An
hour after sunset this evening, look for Antares about 12 degrees to the
right of the Rose, Strawberry, or Flower Moon.
This evening and Thursday are the southernmost moonrises of this
month. Tonight from northern U.S., the Moon rises in ESE less than
half an hour after sunset. Thursday's moonrise is nearly an hour later
than tonight's.
Around this date each year, because of Earth's revolution around the
Sun, the Sun passes 23 degrees south of the bright star Capella. That's
far enough to allow viewing of Capella at both dusk and dawn. An hour
after sunset, look for the star very low, between NW and NNW. An
hour before sunup, look very low, between NNE and NE. If you're at
latitude 44 degrees or farther north, the star is circumpolar and is up all
night, passing just above horizon, due north, in middle of night
(midway between sunset and sunrise tonight).
An hour before sunrise on Friday, the two brightest "stars" are Venus,
very low, between ENE and E, and Jupiter in SE, 50 degrees to Venus'
upper right. Between them, fainter Saturn is in E, 15 degrees to Venus'
upper right.
From the latitude of East Lansing, Michigan (42.7 degrees north), the
earliest sunrises of the year occur the next few mornings.
An hour after sunset these evenings, look for the bright Summer
Triangle in NE to E. It is comprised of bright blue-white Vega in ENE;
Deneb 24 degrees to its lower left; and Altair low in E, 34 degrees
lower right of Vega and 38 degrees lower right of Deneb.
Arcturus, currently the evening sky's brightest star, passes high in south
during evening twilight. Follow this golden-orange beacon until it sinks
into the west-northwest at dusk in November.
Even though Mercury passed beyond the Sun just 6 nights ago and
tonight lies a scant 7 degrees upper left of the setting Sun, it may be
nonetheless already be possible to observe the planet. Tonight 20
minutes after sunset, use binoculars to scan the horizon near the place
where the Sun had set earlier. From the latitude of lower Michigan,
Mercury will be just 2 degrees above the horizon, so you'll need an
unobstructed view. Mercury sets later each evening in a darker sky, so
by week's end it may be visible with unaided eye.
An hour before sunrise on Tuesday, note the string of planets Jupiter,
Saturn, and Venus, in order 15, 50, and 70 degrees to Moon's lower
left. Look each morning through June 21.
On Wednesday an hour before sunup, the Last Quarter Moon is in SE,
with bright Jupiter a couple of degrees to its upper left. Brilliant Venus
is very low in ENE, 55 degrees to Jupiter's lower left. Saturn lies
between the two bright planets, 21 degrees to Venus' upper right. Look
a half hour earlier to glimpse the Pleiades cluster 10 degrees to Venus'
left.
An hour before sunup on Thursday, the fat waning crescent Moon is in
ESE, with Jupiter about 13 degrees to its upper right. Venus is very low
in ENE, 43 degrees to Moon's lower left. Saturn is about midway
between Moon and Venus.
On Friday an hour before sunup, between E and ESE, find the crescent
Moon with Saturn 7 degrees to its left. Bright Jupiter is in SE, about 27
degrees to Moon's upper right, and brilliant Venus is very low in ENE,
about 30 degrees to Moon's lower left.
On Saturday an hour before sunrise, crescent Moon is in E with Saturn
8 degrees upper right. Jupiter is in SE, 34 degrees to Saturn's upper
right, their least separation this year. Venus is about 17 degrees to
Moon's lower left and 24 degrees to Saturn's lower left.
Very low in ENE one-and-a-half hours before sunup on Sunday, the
thin crescent Moon has just cleared the horizon. Brilliant Venus lies just
5 degrees to its upper left, and the Pleiades star cluster (best seen in
binoculars) lies another 7 degrees to Venus' upper left. Saturn in E and
Jupiter in SE lie in a straight line 25 and 59 degrees to Venus' upper
right.
Summer begins today at 10:03 a.m. EDT, as Sun stands directly over
Tropic of Cancer.
Forty-five minutes after sunset, try for Mercury very low in WNW. As
sky darkens, use binoculars and look for Pollux and Castor, 4-1/2
degrees apart and 10 degrees above Mercury. The three bodies form an
isosceles triangle tonight. Watch for changes this week as Mercury
passes to their lower left.
On Monday about 45 minutes before sunup, can you see the thin old
crescent Moon rising in ENE about 11 degrees lower left of Venus?
From far Southwest U.S., the star Aldebaran rises very closely lower
left of the crescent, and is covered by Moon's bright limb before
sunrise. Optical aid will be needed to see the event in bright twilight
around these times: Tucson, 5:02 a.m., San Diego, 5:06 a.m.; Los
Angeles, 5:10 a.m.; San Francisco 5:29 a.m.
The Summer Triangle -- Vega, Deneb, and Altair -- remains visible all
night until nearly mid-August. Tonight, look for it in NE to E at dusk,
and west of overhead at dawn. Week by week, watch it ascend higher in
the east at dusk, and lower in the west at dawn.
Moon is New tonight at 11:50 p.m. EDT. One-and-a-half hours before
sunup on Wednesday, look very low in ENE for brilliant Venus with
the Pleiades star cluster within 6 degrees to its upper left. Planet and
cluster appear closest this morning; binoculars give best view. As sky
brightens, watch for Aldebaran rising 11 degrees to Venus' lower left.
About 25 minutes after sunset, from southern California and Hawaii,
the thin young crescent Moon is setting in WNW, 7 or 8 degrees lower
left of Mercury. Viewers in the rest of the U.S. will need to wait until
Thursday evening to see the first crescent Moon.
About 45 minutes after sunset, look for thin crescent Moon very low in
WNW, with Mercury 9 degrees to its right. Using binoculars as twilight
deepens, look for the Gemini twins: Pollux 5 degrees to Mercury's
upper right, and Castor nearly as far to Pollux's right.
Nearly an hour after sunset, locate crescent Moon low in W to WNW,
with Mercury some 19 degrees to its lower right, and Regulus about the
same distance to Moon's upper left. Tonight Mercury is at its closest to
fainter Pollux. Look for that star 4.8 degrees to the planet's upper right.
Castor is 4.5 degrees to right of Pollux (and a little higher, from
northern U.S.) Use binoculars to hop from Mercury to Pollux to Castor.
Binoculars magnifying 7X to 10X should fit two of the three bodies
within the field of view at once.
This Friday and Saturday, MSU Observatory will be open for public
viewing from 9:00 until 11:00 p.m. if skies are clear.
Nearly an hour after sunset, locate the waxing crescent Moon in W with
Regulus 5 or 6 degrees upper left, and bright Mercury about to set 30
degrees to Moon's lower right. Using binoculars, check for Pollux and
Castor about 5 and 10 degrees to Mercury's upper right. The three
objects are in a slightly bent line tonight. Check again in coming nights.
About an hour after sunset, look for Moon in W with Regulus, heart of
Leo, about 7 degrees to its lower right. Bright Mercury is very low in
WNW, some 40 degrees to Moon's lower right. Binoculars show
Pollux 6 degrees to Mercury's right and a little higher. Castor is 4-1/2
degrees from Pollux. The three bodies lie in a straight line tonight.
An hour before sunup, the two brightest "stars" are Venus, very low in
ENE, and Jupiter, well up in SE. On Monday, Saturn is midway
between them, 34 degrees from each.
An hour before sunup on Tuesday, locate Venus very low in ENE.
Using binoculars, look for the first-magnitude star Aldebaran, eye of
Taurus, 5 degrees below Venus. Watch for interesting changes as the
stars of Taurus get a little higher each morning.
An hour after sunset, the fat crescent Moon is in SW to WSW. Five
bright objects mark the approximate plane of the solar system this
evening: The Moon, Regulus in west 32 degrees to Moon's lower right,
and Mercury very low in WNW 30 degrees to lower right of Regulus;
Spica in SSW to SW, 23 degrees to Moon's left, and Antares in SSE,
46 degrees to Spica's lower left.
