Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2021–2022 evening apparition. It will be shining brightly at mag -4.4.

From Los Angeles , this apparition will not be one of the most prominent but , reaching a peak altitude of 24° above the horizon at sunset on 3 Dec 2021.

2021–2022 evening apparition of Venus

26 Mar 2021 – Venus at superior solar conjunction
28 Oct 2021 – Venus at dichotomy
29 Oct 2021 – Venus at greatest elongation east
03 Dec 2021 – Venus at highest altitude in evening sky
07 Dec 2021 – Venus at greatest brightness
08 Jan 2022 – Venus at inferior solar conjunction

The table below lists the altitude of Venus at sunset over the course of the apparition. All times are given in Los Angeles local time.

Date Sun
sets at
Venus
sets at
Altitude
at sunset
Direction
at sunset
Mag Phase
04 Sep 202119:1420:5519°south-west-4.072%
14 Sep 202119:0020:4519°south-west-4.168%
24 Sep 202118:4620:3719°south-west-4.165%
04 Oct 202118:3220:3119°south-west-4.261%
14 Oct 202118:1920:2820°south-west-4.357%
24 Oct 202118:0720:2821°south-west-4.452%
03 Nov 202117:5720:3022°south-west-4.447%
13 Nov 202116:5019:3323°south-west-4.541%
23 Nov 202116:4519:3324°south-west-4.635%
03 Dec 202116:4319:2724°south-west-4.727%
13 Dec 202116:4419:1023°south-west-4.718%
23 Dec 202116:4818:3818°south-west-4.59%
02 Jan 202216:5417:48south-west-4.22%

A graph of the phase of Venus is available here.

Apparitions of Venus

05 Jan 2019 – Morning apparition
24 Mar 2020 – Evening apparition
13 Aug 2020 – Morning apparition
29 Oct 2021 – Evening apparition
20 Mar 2022 – Morning apparition
04 Jun 2023 – Evening apparition
23 Oct 2023 – Morning 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 17h24m10s 26°49'S Ophiuchus 24.6"
Sun 14h11m 13°12'S Virgo 32'11"

The coordinates above are given in J2000.0.

The sky on 28 Oct 2021

The sky on 28 October 2021
Sunrise
07:06
Sunset
18:03
Twilight ends
19:28
Twilight begins
05:42


Waning Crescent

47%

22 days old

Planets
Rise Culm. Set
Mercury 05:42 11:31 17:21
Venus 11:04 15:48 20:31
Moon 23:22 06:45 14:04
Mars 06:36 12:10 17:44
Jupiter 14:41 20:02 01:22
Saturn 13:52 19:00 00:08
All times shown in PDT.

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

29 Aug 2020  –  Venus at highest altitude in morning sky
29 Oct 2021  –  Venus at greatest elongation east
03 Dec 2021  –  Venus at highest altitude in evening sky
19 Feb 2022  –  Venus at highest altitude in morning sky

Image credit

© NASA/Ricardo Nunes

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