Tag: Pleiades

Astronomy, Sky Watching

Skywatching April 2013


Image Source

Daylight continues to increase throughout April.  Nearly 80 minutes of daylight are added during the month as the sun rises north of east, rises higher in the south and sets north of west this month.

Moon Phases

Moon Phase Date Moonrise Moonset
Last Quarter April 2 1:39 a.m. 12:33 p.m.
New Moon April 10 5:59 a.m. 8:49 p.m.
First Quarter April 18 12:16 p.m. 2:25 a.m. (4/19)
Full Moon April 25 7:56 p.m. 6:20 a.m. (4/26)

Data from US Naval Observatory

The Evening Sky

Jupiter continues to dominate the sky throughout the month.  On April 1, this giant planet is about halfway up in the western sky at sunset.  It appears lower in the west each week at the same time.

jup_moon-0414

On April 14, the waxing crescent moon appears about 4 degrees to the left of Jupiter.  The chart above shows the grouping at 8:30 p.m. CDT.  The moon and Jupiter appear in front of the stars of Taurus with its bright star Aldebaran and prominent Pleiades star cluster.

Saturn rises into the eastern sky shortly after sunset this month.

sat_opposition

On April 28, Earth moves between Saturn and the sun as shown in the diagram above.  (Click the chart to see it larger.)  At this time, Saturn is visible in the sky all night and it is closest to Earth as it gets.  At opposition, Saturn rises in the southeast at sunset.  During the evening hours it rises higher into the sky, appearing south at midnight.  During the early morning hours, it moves westward appearing lower in the southwest as it sets at sunrise.

moon_sat.jpg

A few days before opposition, the moon appears near Saturn.  The chart above shows the moon’s eastward movement at 10 p.m.  CDT each evening.  On April 24, the bright nearly full moon is to the lower left of Spica.  The next night the moon appears below Saturn.

Venus begins rapid movement into the evening sky after is March superior conjunction.  By month’s end, it is about 9 degrees to the east of the sun and difficult to see. Early next month, it appears in the evening sky near the the waxing crescent moon.  For more about Venus as an Evening Star, see our detailed posting here.

Mars is not visible this month.  On April 18, the Red Planet is behind the sun at conjunction.  It will return to the morning sky during early summer, appearing near Jupiter in the morning of July 22.

Presentation1

This chart shows the relative positions of Earth, Sun, and Mars on April 18 when Mars is at conjunction.  (Click the image to see it larger.)

Morning Sky

Mercury  lingers in the April predawn sky early in the month, although it rises in mid-twilight.

merc_lune

On the morning of April 8, the waning crescent moon appears near Mercury.  The chart above shows the pair at 6 a.m. CDT, less then 30 minutes before sunrise.  Find a clear eastern horizon.  Locate the moon with binoculars and then look for Mercury  about 7 degrees to the lower right.  With 7×50 binoculars, the celestial pair may just fit into the binocular field.  Hold the binoculars so that the moon is in the upper left of the field and Mercury may appear to the lower right of the field.  Depending on the binocular, Mercury may appear just outside the view with the moon, so  move the binocular slightly so the moon leaves the field and Mercury enters the view.

By month’s end, the planet is lost in the sun’s glare.

sol_sys_0412

As viewed from above the chart shows the positions of the visible planets on April 15, 2013.   (Click the image to see it larger.) The sun is between Venus and Mars, making them difficult to observe.  Jupiter is on the evening side of Earth, while Saturn is near opposition as explained above.  Mercury is on the morning side of the sky, but difficult to observe.

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Astronomy, Sky Watching

Sky Watching March 2013

Image Credit

March is a time of transition from the long, cold nights of winter to the longer days of spring.  We adapt to this change by moving our clocks on hour ahead of the sun on the morning of March 10 in most of the United States.  While there’s still not much daylight to save or shift to evening hours, daylight increases by nearly 85 minutes during the month.

On March 20, astronomical spring begins in the northern hemisphere.  At 6:02 a.m. CDT, the sun’s rays are most direct on the equator, marking the vernal equinox.

Moon Phases

Moon Phase Date
Last Quarter March 4
New Moon March 11
First Quarter March 19
Full Moon March 27

Comet PanSTARRS

Comet PanSTARRS emerges from behind the sun in March.  While this posting is being composed in late February 2013, the comet’s brightness seems dimmer than once predicted.  The following video explains the difficulty in predicting comet brightness and more about the comet:

pans_luneOn the evening following New Moon, the crescent moon appears near the comet as shown in the chart above.  Look for the crescent moon low in the western sky.  Binoculars may be required to see the comet.

Evening Sky

Jupiter is high in the southwest at sunset, setting in the west at 1 a.m. CST early in the month.  By month’s end it sets at 12:30 a.m. CDT.

jup_luneJust a few nights after the moon appears with Comet PanSTARRS, it appears near Jupiter.  The chart above shows the moon and Jupiter in front of the stars of Taurus.   The bright star Aldebaran is nearby along with the bull’s bright star clusters:  Pleiades and Hyades.


sat_luneThe above chart shows Saturn and Spica with the Moon on March 1 and March 2 at 5 a.m. CST in the southern sky.

sat_lune_2Later in the month, the moon moves past Spica and Saturn again.  The chart shows them in the southwest at 5 a.m. CDT.  By month’s end, Saturn rises at 9:30 p.m. CDT.

Venus and Mars are not visible this month.   Venus reaches superior conjunction on March 28 and is set to move into the western evening sky in April to become a bright Evening Star.  (See our posting for Venus as an Evening Star, 2013-2014.)

Slide1This chart shows the positions of Earth, Sun, and Venus when Venus is at superior conjunction on March 28.  It is on the far side of the sun and lost in the sun’s brilliance.

Mars moves deeper into bright evening twilight and approaches conjunction on April 18 then moving into the morning sky visible in the eastern sky before sunrise starting in late June.

sol_sysThis chart shows the planets visible from Earth in their relative positions in the solar system on March 15, 2013.  (Click the image to see it larger.  On the this date, Mercury, Venus, and Mars appear in the sun’s bright glare.  Jupiter and Saturn are seen easily seen as they are away from the sun’s bright glare.

With the changing of the seasons and the bright winter stars fading in the western sky, March offers more daylight and the possibilities of a bright comet.

Astronomy, Sky Watching

Jupiter Tonight, February 20, 2013

DSC08499

Bright Jupiter shines from high in the southern skies during the early evening of February 2013 as seen in this 30-second exposure image as seen from the Chicago area. ( Click the image to see it larger.)  This giant planet shines from in front of the stars of Taurus and its bright star Aldebaran.  Two bright star cluster, Pleiades and Hyades, are part of the constellation and shine nearby.

The waxing gibbous Moon is just outside the frame at the upper left.

For more about skywatching this month, see our February posting.

Astronomy, Sky Watching

Skywatching February 2013

Orion the Hunter is visible in the southern
skies during the early evening hours of February.
(NASA photo)

Sun

Daylight rapidly increases during February.  On the first day of the month, the sun is in the sky for slightly over 10 hours.  By month’s end, daylight lasts for nearly 11.3 hours.  The net gain during the month is 80 minutes.

Moon Phases

Phase Date Moonrise Moonset
Last Quarter Feb 3 12:28 a.m. 10:45 a.m.
New Moon Feb. 10 6:41 a.m. 6:10 p.m.
First Quarter Feb 17 11:11 a.m. 1:24 a.m.  (02/18)
Full Moon Feb 25 5:50 p.m. 6:31 a.m. (02/26)

Times from the U.S. Naval Observatory

Evening Sky

Mercury makes its best appearance of the year in the western evening sky.  Because it appears in the west for a short time after sunset, viewers need a good horizon and a clear western sky.  Mercury passed behind the sun (superior conjunction) on January 18, moving east (evening) of the sun.  It has been emerging from the sun’s glare since.

mars_merc

On February 8, Mercury passes within a full moon diameter (0.3 degrees) of dimmer Mars.  With the view of a clear horizon, look for the pair about 30 minutes after sunset through binoculars in the west-southwestern sky.

merc_lune

On the evening of February 11, the moon passes 6 degrees to the upper right of Mercury as shown in the chart above with planet and moon displayed at 6 p.m. CST.

merc_gee

On February 16, Mercury reaches its greatest angular separation ( greatest elongation) (18 degrees) from the sun as seen in our skies.  This makes it the best evening appearance of the year as seen from the Chicago area and the northern mid-latitudes.  Mercury appears in the evening sky three times this year and three times in the morning sky.  The best morning appearance for the Chicago area is in mid-November.

The chart above shows Mercury at sunset during its greatest eastern elongation with its invisible orbit sketched in the view.  The planet has reached a place on its orbit where it appears farthest away from the sun.  Mars is below Mercury.

Mercury is rarely visible in a dark sky, usually setting during twilight in its evening appearance or rising during early morning twilight at its morning appearance.

jup_lune

Jupiter is a the dazzling “star” visible high in the southern skies during the early evening hours throughout the month.  At mid-month, the moon passes Jupiter.  On February 17, the moon is 5 degrees to the lower right of Jupiter.  On the next evening, the pair is separated by nearly 7 degrees.

Jupiter is in front of the stars of Taurus with its bright star Aldebaran and two bright star clusters:  Pleiades and Hyades.  Look at the clusters through binoculars on evenings when the moon is not in that part of the sky.

Morning Sky

Saturn is visible in the southern predawn skies during February.  At the beginning of the month, Saturn rises in the southeast at 12:30 a.m. and by month’s end it appears at 10:45 p.m.  The bright star Spica appears about 18 degrees to the right of Saturn.

sat_spica_lune

Early in the month, the moon passes Spica and Saturn.  On the morning of February 2, the moon is 5 degrees to the lower left of Spica and 12 degrees to the lower right of Saturn.  On February 3, the moon is 4.5 degrees below Saturn as shown on the above chart.

Venus rapidly moves into the sun’s bright glare during the month to reappear in the evening sky in the spring, closing out its morning apparition for 2012-2013.

sol_sys

If we could see the solar system from above, we could see its distribution of planets around the sun.  (Click the image to see it larger.) Venus is moving behind the sun as seen from Earth.  Mercury and Venus appear together in the evening sky.

Take a look at the February sky!

Astronomy, Sky Watching

Jupiter Tonight, January 15, 2013

DSC08450

Jupiter and the bright winter stars shine through high clouds as seen in this image made at 9:20 p.m. CST from the Chicago area. (Click the image to see it larger.)  Jupiter is in front of the stars of Taurus that includes Aldebaran the Pleiades star cluster.  Jupiter continues to retrograde, appear to move west compared to the background stars, throughout this month.

Orion is nearby with its bright stars Betelgeuse and Rigel.

Details are in our monthly skywatch.

Astronomy, Sky Watching

Jupiter Tonight, January 1, 2013

DSC08396

Jupiter is visible this evening in the eastern sky as seen in this 30-second exposure at 6:10 p.m. CST from the Chicago area.  (Click the image to see it larger.)  This giant planet is in front of the stars of Taurus with its brightest star Aldebaran.  The Hyades star cluster is nearby and an excellent binocular target.  The Pleiades star cluster, another excellent view through binoculars, appears above Jupiter.  Elnath represents one of the bull’s horns.  Capella (Auriga) is also visible in this view.

During the night, Jupiter appears farther south toward midnight and in the west during early morning hours.  It sets well before sunrise.

For more about the sky this month, see our January 2013 skywatching posting.

Astronomy, Sky Watching

Jupiter, Aldebaran and Orion Tonight, December 21, 2012

After several cloudy, rainy, and snowy days, a clear sky returned this evening. This 30-second exposure shows the southeastern sky at 9:10 p.m. CST from the Chicago area. (Click the image to see it larger.)  Bright Jupiter is in front of the stars of Taurus with its bright star Aldebaran.  They are paired high in the sky.  Elnath and Zeta Tauri represent the bull’s horns.  Two star clusters, Pleiades and Hyades, are excellent targets through binoculars.

Orion follows Taurus in the sky with its bright stars Betelgeuse and Rigel.  The Orion Nebula, a star forming region, is another excellent target through binoculars.

For our monthly sky watching posting, click here.