2016, August 27: A Venus-Jupiter Epoch Conjunction


The June 30, 2015, Venus-Jupiter Conjunction.  The 2016 conjunction is closer.

Update 08/27/16

DSC03635

Here is the view of the conjunction on 8/27/16.  Click the image to see Venus and Jupiter.

The link to our video about this conjunction

An Epoch Conjunction

Just 424 days after the last Epoch Conjunction, Venus and Jupiter pass again in the western evening sky on August 27, 2016, shortly after sunset.  The image above shows the two planets when they were about one-third of a degree apart during the 2015 conjunction.  The 2016 conjunction is three times closer.  This article outlines the circumstances of conjunctions between Venus and Jupiter, the events of this conjunction, and concludes with a list of future Venus-Jupiter conjunctions.

See this article for more as Venus as an Evening Star during 2016-2017.

Conjunctions of the bright planets occur when they appear to move past each other in the sky.  Sometimes they seem to nearly meet, although they are millions of miles apart.  A Venus-Jupiter conjunction occurs between 34 days and 449 days, depending on the relative positions of the three planets (this includes Earth).  Venus revolves around the sun once in about 225 days.  Because our planet is moving, Venus catches up to and passes by Earth every 584 days.  Jupiter is a slower moving participant in this celestial waltz as it revolves around the sun once in nearly 12 years.

Venus-Jupiter conjunctions occur somewhat frequently; the close ones of are great visual interest, because to the unaided eye, the planets appear to merge together.  While not a “once-in-a-lifetime”event, these close conjunctions are infrequent enough to attract the attention of even the casual sky watchers.  Robert C. Victor, former staff astronomer at Abrams Planetarium, calls these close conjunctions “epoch conjunctions.”

Venus is always visible near the sun as it is closer to the sun than Earth.  From our planet it never appears more than about 45 degrees from the sun.  When it is east of the sun, it appears in the western sky just after sunset.  When it is west of the sun, it appears in the eastern sky, just before sunrise.

Jupiter’s movement in the sky largely follows the earth’s revolution around the sun and mostly reflects the annual westward advancement of the starry background.  Jupiter first makes a morning appearance in the eastern sky, just past conjunction when Jupiter is on the far side of its orbit behind the sun.  Each week it appears higher in the sky and farther west at the same time each morning.  Several months later, it appears in the western sky just before sunrise from this slow westward celestial migration.  At this time it is at opposition with Earth between the sun and Jupiter; they are on opposite sides of our sky.  At this time, Jupiter rises a sunset, appears in the south at midnight and sets at sunrise — appearing in between at other times during the night.  Jupiter continues to rise earlier each week, eventually appearing in the south at sunset.  As Jupiter heads for conjunction (behind the sun) it appears in the western sky at sunset, eventually setting with the sun.  This entire cycle takes 399 days.

Because Venus’ orbit is inside Earth’s orbit, Venus never appears more than 45 degrees from the sun, the Venus-Jupiter conjunction appears within region of the sky when Jupiter is near conjunction.  Additionally, if the Venus-Jupiter conjunction occurs too close to the sun, the planets are hidden in the sun’s brilliant glare.  In recent times, 75% of the conjunctions occur when Venus and Jupiter are very close to the sun.

jup_venus

During the August 2016 conjunction, Venus is emerging from behind the sun (superior conjunction).  Venus is only 22 degrees from the sun, setting 56 minutes after the sun, and before Nautical Twilight.  Jupiter is nearing its solar conjunction which is caused more by the earth’s revolution than Jupiter’s orbital movement.  The two planets are about 450 million miles apart, although they appear about 7′ (7 minutes= 0.10 degrees, much less than a full moon diameter) apart.

The Conjunction

Here are the events leading up to the conjunction.

ven_jup_160801

On August 1, Venus is low in the western sky.  Find a clear horizon to see it.  Bright Jupiter is 26 degrees to the upper right of Venus.  Mercury is  about 8 degrees to the upper left of Venus.

5_planets_160804

While not a good appearance, the evening of August 4, 2016, presents another opportunity to view all five naked eye planets simultaneously.  Locate a clear horizon looking west.  Venus stands about 3 degrees above the western horizon.  While it is bright in the twilight, binoculars may be needed to first locate it.  A thin crescent moon appears 10 degrees to the upper left of Venus, with Mercury  2 degrees to the upper right of the Moon.  Jupiter is higher to the upper left of the moon (14 degrees).  Saturn and Mars are in the southern sky, near the star Antares.

ven_jup_160806

On August 6, the separation between Venus and Jupiter decreases to 21.5 degrees with the moon 10 degrees to the upper left of Jupiter.

ven_jup_160815

On August 15, Mercury is rapidly disappearing from the sky.  Tonight Venus and Jupiter are 12 degrees apart.

jup_ven_160820

By August 20, the Venus-Jupiter distance is 7.5 degrees.

ven_jup_160824

On August 24, the pair is 3 degrees apart.

ven_jup_160826

Two evenings later and the evening before the conjunction, the Venus-Jupiter distance is 54′ apart.

ven_jup_160827

August 27, 2016 is conjunction evening when the two planets are 7 arc minutes apart!

telescope_160827

In a telescope at about 80 power, Jupiter and its four largest moons are visible along with Venus.  The view through your telescope may be inverted or backwards left to right, depending on the optical design.  The four largest moons are in a plane that is along the cloud bands of the planet.

ven_jup_160828

On the evening following the conjunction, the planets are 1 degree apart. with Jupiter to the lower right of Venus.

ven_jup_160830

On August 30, the planets have separated to 3 degrees.

The planets continue to separate and Jupiter disappears into the sun’s glare heading for solar conjunction (September 26, 2016).

Upcoming Venus-Jupiter Conjunctions

The table below shows the next 7 close Venus-Jupiter conjunctions.  The November 2017 conjunction and the February 2025 event rival this conjunction in separation.   Following the conjunctions mentioned on this list, a close conjunction (28′) occurs on August 23, 2038 followed by a closer conjunction occurs on November 2, 2039 (13′).  Other more widely spaced Venus-Jupiter conjunctions (30′ to 2 degrees) occur in the interim.

Conjunction Dates Separation Location Visibility
.
November 13, 2017 20’ Morning(east) During this conjunction the planets rise in the east-southeast about 75 minutes  before sunrise.  In separation, it rivals the June 2015 conjunction, but it appears low in the sky.
November 24, 2019 1 degree, 28 minutes Evening(west) The planets in this widely spaced conjunction are nearly 3 full moon diameters apart.  They are visible low in the southwestern sky during twilight and early evening, setting about 1 hour, 35 minutes after sunset.
January 22, 2019 2 degrees, 24 minutes Morning (east) The planets in this widely spaced conjunction are far apart visually, but easily seen as they rise about 3 hours before sunrise and appear in low in the southeastern sky as morning twilight begins.
February 11, 2021 26’ Morning This pairing is very difficult to see in the eastern sky as the planets rise in bright twilight just 25 minutes before sunrise.
April 30, 2022 29’ Morning The planets rise in the eastern sky about 90 minutes before sunrise.  In separation, this rivals the June 2015 conjunction, although it is lower in the sky.
March 1, 2023 32’ Evening This conjunction rivals the June 2015 pairing, with the planets high in the west after sunset, setting 2 hours, 30 minutes after the sun.
May 23, 2024 15’ Morning This pairing is impossible for casual observers  to see as it occurs when the planets are nearly behind the sun hidden in the solar glare.
Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: