Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2157–2158 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 28° above the horizon at sunrise on 10 Jan 2158.

2157–2158 morning apparition of Venus

28 Nov 2157 – Venus at inferior solar conjunction
31 Dec 2157 – Venus at greatest brightness
10 Jan 2158 – Venus at highest altitude in morning sky
07 Feb 2158 – Venus at dichotomy
08 Feb 2158 – Venus at greatest elongation west
13 Sep 2158 – Venus at superior solar conjunction

A graph of the phase of Venus is available here.

Apparitions of Venus

13 Feb 2156 – Evening apparition
05 Jul 2156 – Morning apparition
18 Sep 2157 – Evening apparition
08 Feb 2158 – Morning apparition
26 Apr 2159 – Evening apparition
15 Sep 2159 – Morning apparition
01 Dec 2160 – 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 18h00m30s 19°53'S Sagittarius 24.8"
Sun 21h17m 15°44'S Capricornus 32'26"

The coordinates above are given in J2000.0.

The sky on 17 May 2024

The sky on 17 May 2024
Sunrise
05:30
Sunset
20:06
Twilight ends
22:02
Twilight begins
03:34


Waxing Gibbous

78%

9 days old

Planets
Rise Culm. Set
Mercury 04:37 11:14 17:50
Venus 05:21 12:28 19:36
Moon 14:23 20:52 03:10
Mars 03:42 09:58 16:15
Jupiter 05:38 12:51 20:05
Saturn 02:47 08:27 14:07
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

10 Jan 2158  –  Venus at highest altitude in morning sky
08 Feb 2158  –  Venus at greatest elongation west
18 Apr 2159  –  Venus at highest altitude in evening sky
26 Apr 2159  –  Venus at greatest elongation east

Image credit

© NASA/Ricardo Nunes

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