Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2012 morning apparition. It will be shining brightly at mag -4.3.

From Cambridge , this apparition will be well placed and prominent, reaching a peak altitude of 40° above the horizon at sunrise on 3 Sep 2012.

2012 morning apparition of Venus

05 Jun 2012 – Venus at inferior solar conjunction
10 Jul 2012 – Venus at greatest brightness
15 Aug 2012 – Venus at dichotomy
15 Aug 2012 – Venus at greatest elongation west
03 Sep 2012 – Venus at highest altitude in morning sky
28 Mar 2013 – Venus at superior solar conjunction

A graph of the phase of Venus is available here.

Apparitions of Venus

19 Aug 2010 – Evening apparition
08 Jan 2011 – Morning apparition
26 Mar 2012 – Evening apparition
15 Aug 2012 – Morning apparition
31 Oct 2013 – Evening apparition
23 Mar 2014 – Morning apparition
06 Jun 2015 – Evening apparition

Observing Venus

Venus's orbit lies closer to the Sun than the Earth's, meaning that it always appears close to the Sun and is lost in the Sun's glare much of the time.

It is observable for a few months each time it reaches greatest separation from the Sun – moments referred to as greatest elongation. These apparitions repeat roughly once every 1.6 years.

On these occasions, Venus is so bright and conspicuous that it becomes the third brightest object in the sky after the Sun and Moon. It is often called the morning star or the evening star.

Venus's phase

Venus's phase varies depending on its position relative to the Earth. When it passes between the Earth and Sun, for example, the side that is turned towards the Earth is entirely unilluminated, like a new moon.

Conversely, when it lies opposite to the Earth in its orbit, passing almost behind the Sun, it appears fully illuminated, like a full moon. However, at this time it is also at its most distant from the Earth, so it is actually fainter than at other times.

Venus shows an intermediate half phase – called dichotomy – at roughly the same moment that it appears furthest from the Sun, at greatest elongation. The exact times of the two events may differ by a few days, only because Venus's orbit is not quite perfectly aligned with the ecliptic.

Venus's position

The coordinates of Venus when it reaches dichotomy will be:

Object Right Ascension Declination Constellation Angular Size
Venus 06h29m00s 19°59'N Gemini 23.6"
Sun 09h39m 13°59'N Leo 31'35"

The coordinates above are given in J2000.0.

The sky on 19 May 2024

The sky on 19 May 2024
Sunrise
05:16
Sunset
20:03
Twilight ends
22:04
Twilight begins
03:15


Waxing Gibbous

90%

11 days old

Planets
Rise Culm. Set
Mercury 04:26 11:07 17:49
Venus 05:08 12:22 19:35
Moon 16:16 22:01 03:37
Mars 03:28 09:47 16:07
Jupiter 05:20 12:37 19:54
Saturn 02:32 08:11 13:50
All times shown in EDT.

Source

The circumstances of this event were computed using the DE430 planetary ephemeris published by the Jet Propulsion Laboratory (JPL).

This event was automatically generated by searching the ephemeris for planetary alignments which are of interest to amateur astronomers, and the text above was generated based on an estimate of your location.

Related news

05 Jun 2012  –  Transit of Venus
15 Aug 2012  –  Venus at greatest elongation west
03 Sep 2012  –  Venus at highest altitude in morning sky
31 Oct 2013  –  Venus at greatest elongation east

Image credit

© NASA/Ricardo Nunes

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