Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2023–2024 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 41° above the horizon at sunrise on 20 Oct 2023.

2023–2024 morning apparition of Venus

13 Aug 2023 – Venus at inferior solar conjunction
18 Sep 2023 – Venus at greatest brightness
19 Oct 2023 – Venus at highest altitude in morning sky
22 Oct 2023 – Venus at dichotomy
23 Oct 2023 – Venus at greatest elongation west
04 Jun 2024 – Venus at superior solar conjunction

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

Date Sun
rises at
Venus
rises at
Altitude
at sunrise
Direction
at sunrise
Mag Phase
20 Aug 202305:5305:20east-4.13%
30 Aug 202306:0404:2118°east-4.49%
09 Sep 202306:1503:3828°east-4.518%
19 Sep 202306:2503:1334°east-4.527%
29 Sep 202306:3603:0038°east-4.535%
09 Oct 202306:4702:5841°south-east-4.542%
19 Oct 202306:5903:0241°south-east-4.448%
29 Oct 202307:1103:1241°south-east-4.353%
08 Nov 202306:2302:2639°south-east-4.358%
18 Nov 202306:3602:4237°south-east-4.263%
28 Nov 202306:4803:0135°south-east-4.267%
08 Dec 202306:5803:2132°south-east-4.170%
18 Dec 202307:0603:4228°south-east-4.174%
28 Dec 202307:1004:0425°south-east-4.177%
07 Jan 202407:1104:2622°south-east-4.080%

A graph of the phase of Venus is available here.

Apparitions of Venus

29 Oct 2021 – Evening apparition
20 Mar 2022 – Morning apparition
04 Jun 2023 – Evening apparition
23 Oct 2023 – Morning apparition
10 Jan 2025 – Evening apparition
31 May 2025 – Morning apparition
14 Aug 2026 – 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 10h55m00s 6°38'N Leo 24.3"
Sun 13h47m 11°04'S Virgo 32'08"

The coordinates above are given in J2000.0.

The sky on 22 Oct 2023

The sky on 22 October 2023
Sunrise
07:02
Sunset
17:51
Twilight ends
19:25
Twilight begins
05:28


Waxing Gibbous

64%

8 days old

Planets
Rise Culm. Set
Mercury 07:12 12:34 17:56
Venus 03:07 09:35 16:03
Moon 15:04 19:35 00:13
Mars 07:46 12:59 18:11
Jupiter 18:25 01:21 08:17
Saturn 15:37 20:51 02:06
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

20 Oct 2023  –  Venus at highest altitude in morning sky
23 Oct 2023  –  Venus at greatest elongation west
10 Jan 2025  –  Venus at greatest elongation east
02 Feb 2025  –  Venus at highest altitude in evening sky

Image credit

© NASA/Ricardo Nunes

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