© NASA/Ricardo Nunes

Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed

Objects: Venus
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Venus will reach half phase in its 2020 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 39° above the horizon at sunrise on 28 Aug 2020.

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.

The table below lists how high Venus will appear at sunrise over the course of the apparition. All times are given in Cambridge local time.

Date Sun
rises at
rises at
at sunrise
at sunrise
19 Jun 202005:1003:5512°east
29 Jun 202005:1303:2119°east
09 Jul 202005:1902:5525°east
19 Jul 202005:2702:3630°east
29 Jul 202005:3702:2433°east
08 Aug 202005:4702:1937°east
18 Aug 202005:5802:1938°east
28 Aug 202006:0802:2539°east
07 Sep 202006:1902:3639°east
17 Sep 202006:2902:5139°east
27 Sep 202006:4003:0937°east
07 Oct 202006:5103:2936°east
17 Oct 202007:0303:5034°south-east
27 Oct 202007:1504:1232°south-east
06 Nov 202006:2703:3429°south-east
16 Nov 202006:4003:5826°south-east
26 Nov 202006:5204:2223°south-east

A graph of the phase of Venus is available here.

Observing Venus

The 2020 morning apparition of Venus
03 Jun 2020 – Venus at inferior solar conjunction
08 Jul 2020 – Venus at greatest brightness
12 Aug 2020 – Venus at dichotomy
13 Aug 2020 – Venus at greatest elongation west
07 Sep 2020 – Venus reaches highest point in morning sky

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 hours, 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 06h19m30s +20°02' Orion 23.6"
Sun 09h30m +14°43' Leo 31'34"

The coordinates above are given in J2000.0.

The sky on 12 August 2020
Twilight ends
Twilight begins

23-day old moon
Waning Crescent


23 days old

Rise Culm. Set
Mercury 05:18 12:30 19:42
Venus 02:16 09:38 16:59
Moon 23:58 07:06 14:14
Mars 22:25 04:49 11:11
Jupiter 18:03 22:38 03:17
Saturn 18:31 23:12 03:58
All times shown in EDT.


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

12 Aug 2020  –  Venus at dichotomy
13 Aug 2020  –  Venus at greatest elongation west
07 Sep 2020  –  Venus reaches highest point in morning sky
30 Oct 2020  –  Venus at perihelion

Image credit

© NASA/Ricardo Nunes






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