Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2117–2118 morning apparition. It will be shining brightly at mag -4.4.

From Fairfield , this apparition will not be one of the most prominent but prominent, reaching a peak altitude of 26° above the horizon at sunrise on 21 Jan 2118.

2117–2118 morning apparition of Venus

10 Dec 2117 – Venus at inferior solar conjunction
12 Jan 2118 – Venus at greatest brightness
21 Jan 2118 – Venus at highest altitude in morning sky
20 Feb 2118 – Venus at dichotomy
20 Feb 2118 – Venus at greatest elongation west
25 Sep 2118 – Venus at superior solar conjunction

A graph of the phase of Venus is available here.

Apparitions of Venus

25 Feb 2116 – Evening apparition
17 Jul 2116 – Morning apparition
30 Sep 2117 – Evening apparition
20 Feb 2118 – Morning apparition
08 May 2119 – Evening apparition
26 Sep 2119 – Morning apparition
13 Dec 2120 – 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 18h55m10s 19°34'S Sagittarius 24.7"
Sun 22h07m 11°32'S Aquarius 32'21"

The coordinates above are given in J2000.0.

The sky on 21 Nov 2024

The sky on 21 November 2024
Sunrise
06:45
Sunset
16:28
Twilight ends
18:05
Twilight begins
05:09


Waning Gibbous

53%

20 days old

Planets
Rise Culm. Set
Mercury 08:42 13:07 17:33
Venus 10:12 14:38 19:04
Moon 21:08 04:45 12:10
Mars 20:55 04:18 11:41
Jupiter 17:31 00:58 08:25
Saturn 13:13 18:45 00:17
All times shown in EST.

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

21 Jan 2118  –  Venus at highest altitude in morning sky
20 Feb 2118  –  Venus at greatest elongation west
25 Apr 2119  –  Venus at highest altitude in evening sky
08 May 2119  –  Venus at greatest elongation east

Image credit

© NASA/Ricardo Nunes

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