Venus at dichotomy

Dominic Ford, Editor
From the Inner Planets feed


Objects: Venus

Venus will reach half phase in its 2015–2016 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 22 Oct 2015.

2015–2016 morning apparition of Venus

15 Aug 2015 – Venus at inferior solar conjunction
20 Sep 2015 – Venus at greatest brightness
22 Oct 2015 – Venus at highest altitude in morning sky
25 Oct 2015 – Venus at dichotomy
26 Oct 2015 – Venus at greatest elongation west
06 Jun 2016 – Venus at superior solar conjunction

A graph of the phase of Venus is available here.

Apparitions of Venus

31 Oct 2013 – Evening apparition
23 Mar 2014 – Morning apparition
06 Jun 2015 – Evening apparition
26 Oct 2015 – Morning apparition
12 Jan 2017 – Evening apparition
03 Jun 2017 – Morning apparition
17 Aug 2018 – 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 11h04m00s 5°51'N Leo 24.4"
Sun 13h56m 11°55'S Virgo 32'09"

The coordinates above are given in J2000.0.

The sky on 25 Nov 2024

The sky on 25 November 2024
Sunrise
06:45
Sunset
16:14
Twilight ends
17:54
Twilight begins
05:05


Waning Crescent

25%

24 days old

Planets
Rise Culm. Set
Mercury 08:26 12:49 17:13
Venus 10:11 14:34 18:58
Moon 01:14 07:25 13:26
Mars 20:30 03:57 11:23
Jupiter 17:01 00:31 08:02
Saturn 12:50 18:21 23:51
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

22 Oct 2015  –  Venus at highest altitude in morning sky
26 Oct 2015  –  Venus at greatest elongation west
12 Jan 2017  –  Venus at greatest elongation east
03 Feb 2017  –  Venus at highest altitude in evening sky

Image credit

© NASA/Ricardo Nunes

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