Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2138–2139 morning apparition. It will be shining brightly at mag -4.4.

From Cambridge , this apparition will be well placed and prominent, reaching a peak altitude of 38° above the horizon at sunrise on 17 Nov 2138.

2138–2139 morning apparition of Venus

21 Sep 2138 – Venus at inferior solar conjunction
26 Oct 2138 – Venus at greatest brightness
17 Nov 2138 – Venus at highest altitude in morning sky
01 Dec 2138 – Venus at dichotomy
01 Dec 2138 – Venus at greatest elongation west
12 Jul 2139 – Venus at superior solar conjunction

A graph of the phase of Venus is available here.

Apparitions of Venus

08 Dec 2136 – Evening apparition
29 Apr 2137 – Morning apparition
13 Jul 2138 – Evening apparition
01 Dec 2138 – Morning apparition
18 Feb 2140 – Evening apparition
09 Jul 2140 – Morning apparition
23 Sep 2141 – 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 13h17m30s 5°59'S Virgo 24.7"
Sun 16h20m 21°26'S Scorpius 32'25"

The coordinates above are given in J2000.0.

The sky on 3 May 2024

The sky on 3 May 2024
Sunrise
05:34
Sunset
19:46
Twilight ends
21:37
Twilight begins
03:43


Waning Crescent

18%

25 days old

Planets
Rise Culm. Set
Mercury 04:47 11:07 17:27
Venus 05:19 12:07 18:56
Moon 03:21 08:48 14:27
Mars 04:04 10:05 16:07
Jupiter 06:11 13:24 20:37
Saturn 03:32 09:09 14:47
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

17 Nov 2138  –  Venus at highest altitude in morning sky
01 Dec 2138  –  Venus at greatest elongation west
18 Feb 2140  –  Venus at greatest elongation east
01 Mar 2140  –  Venus at highest altitude in evening sky

Image credit

© NASA/Ricardo Nunes

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