The Venus Evening Apparition

of 2019-2020

by Martin J. Powell

The paths of Venus and Mercury through the zodiac constellations during the latter part of Venus' evening apparition in 2019-20 (click on the thumbnail for the full-size image, 180 KB). The earlier part of the apparition appears in the star chart below. Planet positions are plotted for 0 hrs Universal Time (UT) at 5-day intervals. For Venus, apparition data for the dates shown in bright white (at 10-day intervals) are included in the table below.

Both evening and morning apparitions of Mercury are included. Wherever a planet was too close to the Sun to view, the path is shown by a dashed line (- -). Hence Mercury's evening apparition drew to a close in mid-February 2020. It then became lost from view in the evening twilight as it headed towards inferior conjunction with the Sun. The planet re-emerged in the dawn twilight in early March for a morning apparition which lasted through to mid-April. Because Mercury is mostly seen in twilight, many of the fainter stars shown in the planet's vicinity may not have been visible when the planet itself was observed.

The positions at which Venus and Mercury attained greatest elongation from the Sun are indicated by the letters 'GE', with the solar elongation angle in brackets; it is Eastern (E) in the evening and Western (W) in the morning (the elongation of Venus is Easterly throughout the chart coverage). The position at which Venus attained greatest brilliancy for this apparition (apparent magnitude = -4.4) is shown by the letters 'GB'. The February evening apparition of Mercury favoured Northern hemisphere observers whilst the morning apparition of March to April was more favourable for Southern hemisphere observers (who should refer to the Southern hemisphere chart (184 KB) for a more appropriate orientation).

Planetary conjunctions of Venus with Neptune and Venus with Uranus took place on January 27th and March 9th respectively, indicated on the chart by the symbol (for more details see the planetary conjunctions section below). The paths of Uranus and Neptune on this chart are shown only as guides.

The faintest stars shown on the chart have an apparent magnitude of about +4.8. Printer-friendly versions of this chart are available for Northern (84 KB) and Southern hemisphere (85 KB) views. Click here (123 KB) to see a 'clean' star map of the area (i.e. without planet paths); a printer-friendly version can be seen here (61 KB). Astronomical co-ordinates of Right Ascension (longitude, measured Eastwards in hrs:mins) and Declination (latitude, measured in degrees North or South of the celestial equator) are marked around the border of the chart.

The four star names shown in yellow-green were officially adopted by the International Astronomical Union (IAU) in 2017.

Following superior conjunction on August 14th 2019 (when it passed directly behind the Sun in the constellation of Leo, the Lion) Venus' 2019-20 apparition as an 'Evening Star' got underway as the planet emerged in the dusk sky in late September 2019. The time of year at which the planet became visible depended upon the observer's latitude; Southern and Equatorial latitudes were first to see it, low down in the West shortly after sunset. The further North the observer was located, the later the planet emerged; hence mid-Northern latitudes began to see the planet from late October whilst higher-Northern latitudes began to see it from late November (50° North) and mid-December (60° North).

Venus entered the constellation of Virgo, the Virgin on September 9th, crossing to the South of the celestial equator (where the declination of a celestial body is 0°) on September 16th and reaching a solar elongation of 10° East on September 20th. The planet was slow to emerge from the twilight glow, taking several weeks to gain a significant altitude (angle above the horizon) after sunset. In mid-September Venus was positioned at a distant 1.6985 Astronomical Units (AU) from the Earth (254.1 million kms or 157.9 million statute miles), a distance which would continually reduce over the next eight months, through to the end of the apparition.

A Distant Venus imaged by Luis Amiama Gómez (Santo Domingo, Dominican Republic) on March 5th 2018 when the planet was emerging into the dusk sky for the 2018 evening apparition (click on the thumbnail for a larger image, 2 KB). Venus was 13° East of the Sun, 10".1 across and 97% illuminated (Image: ALPO-Japan / Luis Amiama Gómez)

At this early stage of the apparition, when seen through a telescope, the planet showed a broad gibbous phase, around 98% illuminated, shining at an apparent magnitude of -3.8 and measuring only around 10" across (i.e. 10 arcseconds, where 1" = 1/60th of an arcminute or 1/3600 of a degree). Its low altitude, great distance from the Earth and small apparent size made it a difficult object to observe telescopically, with no detail being visible in its clouds. The planet was positioned in central Virgo as the apparition began, moving South-eastwards along the ecliptic (the apparent path of the Sun, Moon and planets) at a steady rate of 1°.2 per day and pulling away from the Sun at about 0°.3 per day.

As Venus was becoming visible from Southern and Equatorial latitudes in late September, the planet was joined from the West by Mercury (mag. -0.2) in the first of three paired apparitions between the two planets which took place during Venus' 2019-20 evening apparition (a paired apparition being when the two planets are visible together for a prolonged period of time, either in the morning sky or the evening sky). It was the third evening apparition of Mercury in 2019, this one being favourable for viewing in the Southern hemisphere (from where the ecliptic presents a steep angle to the Western horizon after sunset at this time of year). Mercury was positioned 5°.5 to the South-east of Venus on September 27th and 6°.3 South-east of Venus on the 30th. Both planets were joined by the waxing crescent Moon on September 29th and 30th.

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On October 3rd Mercury was positioned 6°.9 to the South-east of Venus, having brightened slightly to magnitude -0.1. Venus passed 3°.1 North of Virgo's brightest star Spica ( Vir or Alpha Virginis, mag. +1.0) on the same day. Mercury entered Libra, the Balance (or Scales) on October 9th and entered Chart 1 coverage.

Venus reached 15° East of the Sun on October 10th, entering Libra on October 15th, with Mercury positioned 8° to its South-east. Venus itself entered Chart 1 coverage on October 16th. Mercury (mag. +0.0) reached its greatest elongation from the Sun (24°.6 East) in Southern Libra on October 20th, positioned 7°.3 to the South-east of Venus.

From early to mid-October, observers in Northern Tropical latitudes began to detect the planet, low in the WSW after sunset. Now at a more comfortable solar elongation of 18°, the planet passed 10' South (i.e. 10 arcminutes, where 1' = 1/60th of a degree) of the double star Zubenelgenubi ( Lib or Alpha Librae, mag. +2.8) on October 21st and 8º.0 North of the star Brachium ( Lib or Sigma Librae, mag. +3.3), located at the base of the Scales, on October 23rd.

Venus crossed the ecliptic Southwards on October 25th, then on the following day passed 8º.8 South of the star Zubeneschamali ( Lib or Beta Librae, mag. +2.5), the Northernmost star of the Scales' quadrilateral figure.

Mercury's motion against the background stars of Libra had slowed considerably since the planet entered the evening sky in late September. In the final week of October the planet was moving at a rate of just 0º.5 per day - half the speed it was moving only the week before - whilst Venus continued steadily Eastwards at around 1º.5 per day. Venus was positioned 4°.7 North-west of Mercury on October 27th, 4°.0 North-west of it on the 28th and 3°.5 NNW of it on the 29th.

Venus reached 20º East of the Sun on October 29th. At 1151 UT, observers located in the South-western tip of Australia saw Mercury, Venus and the waxing crescent Moon appear almost in line along 8º.1 in the WSW at dusk. Meanwhile, observers at mid-Northern latitudes were just beginning to detect Venus, low down in the WSW at dusk.

At around 0130 UT on October 30th Venus (mag. -3.8) passed 4°.6 South of the star Zubenelhakrabi ( Lib or Gamma Librae, mag. +3.9). Seven hours later, at 0830 UT, the planet passed 2°.7 North of Mercury (mag. +0.4) in an event called a planetary conjunction. These take place when two planets attain the same celestial longitude, so that they appear close together in the night sky. It was the first of six planetary conjunctions involving Venus which took place during the planet's 2019-20 evening apparition. This particular Venus-Mercury conjunction was nearly in line with the star Lib (Upsilon Librae, mag. +3.6), positioned 5°.8 to the South of Mercury. The giant planet Jupiter (mag. -1.7), located in the neighbouring constellation of Ophiuchus, the Serpent-Bearer, was 26° to the ESE of the planetary pairing. From 15 to 16 hours UT the waxing crescent Moon nicely positioned itself at the centre of the wide planetary grouping, an event ideally seen by observers located in Saudi Arabia, Yemen, the Horn of Africa, Madagascar and the Western Indian Ocean.

Mercury 's Eastward motion against the background stars ceased on October 31st when the planet reached its Eastern stationary point in South-eastern Libra.

Venus left Mercury behind it and entered Scorpius, the Scorpion, on November 1st, passing 3°.9 South of the star  Lib (Theta Librae, mag. +4.1) on November 2nd.

In early November Mercury was moving retrograde (East to West) against the background stars of Libra and was quickly heading back in towards the Sun. Over the next week the planet became lost from view in the dusk twilight.

Venus passed 1º.6 North of the star Dschubba ( Sco or Delta Scorpii, mag. +2.2) on November 3rd and 1°.5 South of the striking double-star Acrab (¹ Sco or Beta-1 Scorpii, combined mag. +2.6), formerly known as Graffias, on November 4th. Between the hours of 0300 UT and 0544 UT on November 5th, Venus passed 0º.6 South of the two Omegan stars Jabhat al Akrab (¹ Sco or Omega-1 Scorpii, mag. +3.9) and ² Sco (Omega-2 Scorpii, mag. +4.3). Together with Dschubba, Acrab and the quadruple star named Jabbah ( Sco or Nu Scorpii, mag. +4.0), they form a distinctive asterism (star pattern) in Northern Scorpius. Venus passed 2º.2 South of Jabbah on the following day (6th).

At around 02 hours UT on November 7th Venus passed 1º.1 North of the eighth-magnitude globular cluster Messier 80 or M80 (or NGC 6093) which, like most of the brighter globulars, appears as a faint, circular, fuzzy spot of light through binoculars under dark skies. The narrow separation allowed the two objects to be contained within the eyepiece view of a wide-field, low-magnification ocular, whilst binocular users saw the planet and cluster appear in close proximity. At 2040 UT on the same day Venus passed 3º.5 North of the variable star named Alniyat ( Sco or Sigma Scorpii, mag. +2.9v).

Venus entered Ophiuchus on November 8th, passing 4º.0 North of Scorpius' brightest star Antares ( Sco or Alpha Scorpii, mag. +1.0v) on the following day (9th). Antares shines with an unmistakable orange-red hue since it is a red supergiant, estimated to measure at least 400 times the diameter of our Sun. It is also a variable star, fluctuating between magnitudes +0.6 to +1.6 over a 5-year period.

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On November 10th Venus passed 5º.5 North of the star Paikauhale ( Sco or Tau Scorpii, mag. +2.8), a name which is Hawaii'an for a vagabond. It is one of several stars which have been formally assigned 'new' names by the International Astronomical Union (IAU) in the last few years. Since 2016 the IAU's Working Group on Star Names has been cataloguing and standardizing the star names used by the international astronomical community. In order to accommodate a wider diversity of global culture, it has adopted some names from mythologies other than Arab, Greek and Roman, whose star names dominate the night sky.

On November 11th Mercury reached inferior conjunction - when it passed directly between the Earth and the Sun - in central Libra. At most inferior conjunctions Mercury passes a short distance to the North or South of the Sun, making it unobservable from the Earth because of the overwhelming solar glare. On this occasion, however, the planet could be seen - with the aid of optical instruments and eye protection - as a tiny black dot crossing the solar disk in a relatively rare transit of Mercury. A similar transit took place in 2016 and another will take place in 2032. At the moment of Mercury's transit, Venus was positioned 23º East of the Sun, shone at magnitude -3.8, appeared 11" across and showed a 92% illuminated gibbous phase.

On November 13th Venus passed 11º.0 North of the star Larawag ( Sco or Epsilon Scorpii, mag. +2.2), positioned about half-way along the Scorpion's tail. It is an Aboriginal name from the Wardaman culture of Northern Australia, and another star which was formally assigned a 'new' name by the IAU - in this case, in 2017. At around 15 hours UT on November 15th Venus passed 2º.5 North of the seventh-magnitude globular cluster M19 (NGC 6273). At 12' (0º.2) in diameter, it is a roughly oval-shaped 'fuzzball' of stars which can easily be seen through binoculars and small telescopes under fully dark skies. Venus passed 8°.1 South of Sabik ( Oph or Eta Ophiuchi, mag. +2.5), the second brightest star in Ophiuchus, on November 17th.

Positioned 2º.8 East of M19 is the fifth-magnitude star Guniibuu (36 Oph A or 36 Ophiuchi A, mag. +5.1), one of a pair of orange dwarf stars (A and B) which are easily split in small telescopes. Assigned the name by the IAU in 2018, it refers to a mythological robin red-breast in Australian Aboriginal culture. Venus passed 2º.5 North of Guniibuu at around 0050 UT on November 18th. During its evening apparition in October 2021, the planet will pass in front of the star - blocking it from view for up to nine minutes - in an event known as an occultation.

Since mid-August Jupiter had been slowly edging its way Eastwards through Southern Ophiuchus at a rate of about 0º.2 per day. The planet was nearing the close of its 2018-19 apparition and would be lost from view by mid-December. On November 16th the giant planet entered Sagittarius, the Archer, the most Southerly constellation of the zodiac. Throughout November Venus had been approaching Jupiter from the West, gaining on the giant planet by about 1º per day. Jupiter was positioned 9º.9 East of Venus on November 15th, 6º.8 East of it on the 18th and 3º.8 ENE of it on the 21st.

Venus passed 0°.8 North of Theta Ophiuchi ( Oph, mag. +3.2), the brightest star in the Southernmost region of Ophiuchus, on November 19th and 12°.8 North of Shaula ( Sco or Lambda Scorpii, mag. +1.6), positioned at the 'sting' of the Scorpion's tail, on November 19th.

A Gibbous Venus sketched by Paul G. Abel (Leicester, UK) on May 21st 2018 using an 8-inch (203 mm) Newtonian reflector telescope at 167x magnification (click on the thumbnail for a larger image, 6 KB). The sketches were produced (left) in white light and (right) with a deep yellow eyepiece filter. Note the planet's characteristic 'W' or 'Y'-shaped cloud markings and how the illuminated phase appears slightly greater when seen through the deep yellow filter (Image: ALPO-Japan / Paul G. Abel)

On November 23rd Venus entered Sagittarius and by midnight UT on November 24th Venus was positioned only 1°.5 to the South-west of Jupiter. At 14 hours UT on the same day the two planets met in conjunction, Venus passing 1°.4 to the South of Jupiter. The planet Saturn (mag. +0.6) was positioned 19° to the East of the pair, the three planets forming a long right-angled triangle to the North of the Archer's famous Teapot asterism. Details of this and the other five planetary conjunctions involving Venus during the 2019-20 apparition are given in the Planetary Conjunctions section below.

For a period of 17 hours between November 26th and 27th, Venus passed 0º.5 South of the sixth-magnitude gaseous nebula commonly called the Lagoon Nebula or M8 (NGC 6523). With an apparent dimension of 90' by 40', the nebula is visible to the naked-eye from dark sites and is a spectacular sight through larger telescopes - particularly those fitted with nebular filters. The planet's passage South of the nebula began at 15 hours UT on the 26th and ended at 08 hours UT on the 27th.

From November 27th through to December 8th, Venus passed to the North of the Teapot. Seen in a North-up orientation, the teapot appears 'tipped up', pouring its contents South-westwards into neighbouring Scorpius. The asterism extends from the star Alnasl ( Sgr or Gamma Sagittarii, mag. +3.0) in the West to the star Tau Sagittarii ( Sgr, mag. +3.3) in the East. The asterism passage got underway on November 27th when Venus passed 5º.7 North of Alnasl, which is positioned at the front of the Archer's bow. Prior to IAU standardisation in 2016 the star was commonly known as Nash.

At 17 hours UT on November 28th Venus attained its most Southerly position in the zodiac for the 2019-20 apparition, at a declination of -24° 47' 14" (-24°.78 in decimal form). Venus then set at its most Southerly point along the local horizon, an effect which was more pronounced the further away from the Equator an observer was situated. At the Equator (latitude 0°), for example, Venus set in the WSW at this time whilst at 55° North (where observers were only just beginning to see it) the planet set in the South-west, some 20° further South along the horizon. Two hours after reaching its most Southerly point, Venus passed through the aphelion point in its orbit, where it was furthest away from the Sun at 0.7282 AU (108.9 million kms or 67.7 million statute miles). Perihelion - its closest point to the Sun - would be reached in the following March.

On November 29th at around 08 hours UT Jupiter, Venus, the crescent Moon and Saturn formed a grouping to the North of the Teapot, extending across 18°.6. It was best seen at dusk from a narrow band of the Earth stretching from South-eastern China through the Philippines, Eastern Indonesia and Eastern Australia. The planetary grouping lasted from around November 14th through to December 8th, the Moon being in the vicinity from November 28th to 30th.

On November 30th Venus passed 5°.1 North of Kaus Media ( Sgr or Delta Sagittarii, mag. +2.7), positioned at the centre of the Archer's bow. Before IAU standardisation in 2016 it was also known by the names Kaus Meridionalis and Kaus Medius.

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On December 1st Venus passed 42' (0°.7) North of Kaus Borealis ( Sgr or Lambda Sagittarii, mag. +2.8), positioned at the top of the Teapot asterism. On December 2nd the planet passed 0º.8 South of the globular cluster M22 (NGC 6656), which is considered to be one of the finest globulars in the night sky. It has an apparent diameter of 24' and its integrated magnitude (i.e. its apparent magnitude if the cluster were concentrated into a single point) is about +5.9. It is just visible to the naked-eye from dark sites, is easily seen through binoculars and is beautifully resolved in telescopes.

In early December, observers at mid-Southern latitudes saw Venus attain its highest altitude in the sky after sunset for the 2019-20 apparition. At 45° South latitude in early December, Venus was around 15° high in the WSW at 30 minutes after sunset, the planet setting over two hours after the Sun. At 35° South in mid-December, the planet attained 18° altitude at 30 minutes after sunset. The significance of the observer's latitude in observing planets at narrow solar elongations was well illustrated at this time; whilst mid-Southern hemisphere observers were enjoying their best views of Venus around mid-December, observers at 60° North latitude were only just catching their first glimpse of the planet after sunset (details of the planet's direction and altitude at 30 minutes after sunset for various latitudes are listed in the table below).

Over the next week Venus passed North of the four stars which form the 'handle' of the Teapot. The planet passed 2°.4 North of Phi Sagittarii ( Sgr, mag. +3.1) on December 4th and 1°.8 North of the constellation's second-brightest star Nunki ( Sgr or Sigma Sagittarii, mag. +2.0) on December 6th. Venus passed 5°.6 North of Ascella ( Sgr or Zeta Sagittarii, mag. +2.6), at the bottom of the Teapot's handle, on December 7th. Finally, on December 8th Venus passed 3°.5 North of Sgr (Tau Sagittarii, mag. +3.3) which marks the Eastern end of the Teapot. The planet passed 3°.1 South of the star Albaldah ( Sgr or Pi Sagittarii, mag. +2.9), positioned at the top of the Archer's head, on December 9th. Venus will occult (pass in front of) Albaldah during its morning apparition in 2035.

Table of selected data relating to the evening apparition of Venus during 2019-20 (click on the thumbnail for the full-size table, 66 KB). The data is listed at 10-day intervals, corresponding with the dates shown in bright white on the star charts 1 and 2. The data for the table was obtained from the software 'Redshift 5' , 'SkyGazer Ephemeris' and Kyle Edwards' 'Solar System Imaging Simulator'. The Venusian disk images were derived from NASA's Solar System Simulator.

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Having left Jupiter well behind it, Venus was fast approaching an even slower-moving Saturn, which was now positioned to the North-east of the Teapot. The ringed planet was in the final weeks of its 2019 apparition and, being very distant and small, was not seen at its best at this time. Its rings were however nicely open and measured 34" across, the globe of the planet measuring 15" across. Saturn (mag. +0.6) was 4°.2 ENE of Venus on December 8th, 3°.2 North-east of it on December 9th and  2°.4 North-east of it on the 10th. On December 11th, as Venus reached a solar elongation of 30° East of the Sun, the planet passed 1°.8 South of Saturn in the third planetary conjunction of the 2019-20 evening apparition (an assessment of the worldwide visibility of this conjunction is discussed in the Planetary Conjunctions section below). Eighteen hours after the conjunction, Venus passed 46' (0°.7) North of the star ₁ Sgr (Chi-1 Sagittarii, mag. +5.0) which the planet will occult during its evening apparition in 2040.

Venus continued its way through Sagittarius to the constellation's much fainter Eastern region. The planet passed 1°.5 North of the star 52 Sagittarii (mag. +4.6) on December 14th, then on the 17th it passed 3°.7 North of Terebellum ( Sgr or Omega Sagittarii, mag. +4.7), a Latin name which derives from an original Greek word meaning 'quadrilateral'. Terebellum is one of a group of four moderately-bright stars positioned within 2° of each other in the 'rump' of the Archer figure. They were named as such by Claudius Ptolemy (ca. 100-170 AD) in his famous star catalogue, the Almagest.

By mid-December Venus was setting in darkness from all but the Polar regions of the world. On December 19th the planet entered Capricornus, the Sea-Goat, passing 9°.0 South of the stars Prima Giedi (¹ Cap, or Alpha-1 Capricorni, mag. +4.2) and, soon afterwards, Algedi (² Cap or Alpha-2 Capricorni, mag. +3.6) on December 21st. Prior to IAU standardisation in 2016 the latter was also known as Secunda Giedi. Prima Giedi and Algedi are separated in the night sky by 6'.4 (0°.1) and are an easy optical double, meaning that they appear to the naked-eye as a double star but they are not physically related - in this case being 700 light years (where 1 light year = 63,240 AU) and 108 light years distant, respectively.

Venus passed 6°.5 South of the constellation's second-brightest star Dabih ( Cap or Beta Capricorni, mag. +3.1) on December 22nd. At around 0157 UT on December 29th the waxing crescent Moon passed in front of Venus, blocking it from view, in an event known as a lunar occultation. It was however only viewable from a sparsely populated region of the world comprising the Southernmost tip of South America and the Antarctic. Details of the timings and track of visibility can be seen by following the link in the Moon near Venus Dates section below.

The Northern hemisphere winter solstice now having passed, both Venus and the Sun began to ascend the ecliptic once more. With the declination of both celestial bodies moving Northwards and the solar elongation of Venus continuing to increase over the next few months, the setting positions of both Venus and the Sun moved Northwards along the local horizon with each passing week. Venus passed 1°.3 South of the star Cap (Theta Capricorni, mag. +4.0), at the centre of Capricornus, on December 31st.

On January 3rd Venus passed 27' (0°.45) South of  Cap (Iota Capricorni, mag. +4.2), positioned at the 'rump' of the Sea-Goat figure. The planet passed 0°.8 North of Nashira ( Cap or Gamma Capricorni, mag. +3.7) on January 7th and Deneb Algedi ( Cap or Delta Capricorni, mag. +2.9) on the 8th, both of these being 'tail' stars of the Sea-Goat. Venus exited the Chart 1 coverage on January 10th and entered Chart 2 coverage on the following day.

By early January Venus had brightened to -3.9 and its apparent size had reached 13". Telescopes showed a notably gibbous phase, about 80% illuminated. On January 11th Venus entered the constellation of Aquarius, the Water-Bearer (alternatively, the Water-Carrier or Waterman), passing 29' (0°.5) North of the star Aqr (Iota Aquarii, mag. +4.2) on January 13th and 4°.5 South of the star Ancha ( Aqr or Theta Aquarii, mag. +4.1) on January 15th. Between January 16th and 19th the planet passed to the South of the Water-Bearer's most recognisable feature: an asterism of four stars informally known as the Steering Wheel, centred on Aqr (Zeta Aquarii, mag. +3.6). On some modern star maps this asterism is seen to depict the head of the Water-Bearer figure; such maps are based on the constellations envisaged in the 1950s by the author and illustrator H. A. Rey (1898-1977). On older star maps, such as the Uranographia published in 1801 by Johann Elert Bode (1747-1826), these stars marked the amphora from which the water was poured. Venus passed 10°.4 South of Sadachbia ( Aqr or Gamma Aquarii, mag. +3.9), at the South-western edge of the modern-day Steering Wheel, on January 16th.

Around mid-January, observers in Southern Tropical latitudes saw Venus reach its highest altitude after sunset for the current evening apparition. From latitude 25° South the planet was positioned 22° above the Western horizon (at 30 minutes after sunset) and set two hours after the Sun. At other latitudes the altitude, direction and visibility duration at one half-hour after sunset were as follows: 16º above the SSW horizon at 60º North, being visible for 3¾ hours thereafter; 25º above the South-west horizon at 40º North, visible for three hours thereafter and 28º above the WSW horizon at the Equator, setting 2½ hours afterwards.

The paths of Venus, Mercury, Mars, Jupiter and Saturn through the zodiac constellations for the earlier part of Venus' evening apparition in 2019-20 (click on the thumbnail for the full-size image, 207 KB). The latter part of the planets' apparition is shown in the chart above. Positions of Venus, Mercury and Mars are plotted for 0 hrs Universal Time (UT) at 5-day intervals; those of Jupiter and Saturn are for the 1st of each month. Both evening and morning apparitions of Mercury are included. Wherever a planet was too close to the Sun to view, the path is shown by a dashed line (- -). Hence Mercury's evening apparition ended in early November 2019 when it became lost from view in the dusk twilight. The planet was then not visible with the naked-eye until it re-emerged in the morning sky about two weeks later (note that a transit of Mercury took place at the planet's inferior conjunction on November 11th 2019, when it was positioned mid-way along its retrograde path in Libra). Because Mercury is mostly seen by naked-eye under twilit conditions, many of the fainter stars shown in the planet's vicinity may not have been visible when the planet itself was observed.

For Venus, apparition data for the dates shown in bright white (at 10-day intervals) are included in the table above. The positions at which Mercury attained greatest elongation from the Sun are indicated by the letters 'GE', with the solar elongation angle in brackets; Eastern elongations apply for evening apparitions and Western elongations for morning apparitions. Note that the October 2019 evening apparition of Mercury shown on the chart favoured Southern hemisphere observers (who should refer to the Southern hemisphere chart (211 KB) for a more appropriate orientation) whilst the November-December morning apparition favoured Northern hemisphere observers.

Planetary conjunctions of Venus with Mercury, Jupiter and Saturn took place on October 30th, November 24th and December 11th respectively, indicated on the chart by the symbol . On these dates, a line drawn through the relevant planet paths (with respect to Celestial North) show them to be in alignment. For more details see the planetary conjunctions section below.

The faintest stars shown have an apparent magnitude of about +4.8. Printer-friendly versions of this chart are available for Northern (95 KB) and Southern hemisphere (95 KB) views. Click here (157 KB) to see a 'clean' star map of the area (i.e. without planet paths); a printer-friendly version can be seen here (76 KB). Astronomical co-ordinates of Right Ascension (longitude, measured Eastwards in hrs:mins) and Declination (latitude, measured in degrees North or South of the celestial equator) are marked around the border of the chart.

The eight star names shown in yellow-green were officially adopted by the International Astronomical Union (IAU) in 2017-18.

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At 0850 UT on January 18th Venus passed 15' (0º.25) South of the star  Aqr (Sigma Aquarii, mag. +4.8), which is positioned more or less at the centre of Aquarius. Venus will occult Aqr during its morning apparition of 2048, at almost the same time as the planet is in conjunction with Mercury. Venus passed 10°.9 South of  Aqr - at the centre of the Steering Wheel - later on the 18th. At the Eastern edge of the 'wheel' asterism is Aqr (Eta Aquarii, mag. +4.0), which on Rey's star maps marked the tip of the Water-Bearer's nose. Venus passed 10°.1 South of the star on January 19th. On January 23rd Venus passed 1º.0 South of the star Aqr (Lambda Aquarii, mag. +3.7), which the planet occulted during its 2014 morning apparition.

At 1924 UT on January 27th Venus passed just 4' (0º.06) to the South of Neptune (mag. +7.9) in a very close conjunction which, owing to the latter planet's dimness, required optical aid to view. However, the sheer brilliance of Venus - a staggering 58,000 times brighter than Neptune - made it an uncomfortable conjunction to view. Neptune entered Aquarius in 2011 and will remain there until 2022.

At 0510 UT on January 28th Venus passed just 1' (0º.01, about four apparent Venus-widths) to the South of the star Aqr (Phi Aquarii, mag. +4.2), which Rey depicted as marking the top of the Water-Bearer's amphora (Bode's star map depicted them as part of the stream of water which flowed from the amphora towards the star Fomalhaut in the constellation of Piscis Australis). Phi Aquarii is another star which the planet will occult at a future date - in this case on January 27th 2028, one 'Venus cycle' hence (see the accompanying article describing The Venus 8-year Cycle).

Between January 29th and February 4th Venus passed about 7° degrees South of the Circlet of Pisces, an asterism positioned at the Western end of Pisces, the Fishes. The Circlet is the most distinct feature of the constellation and comprises seven stars of fourth and fifth magnitude.

Venus entered Pisces on February 2nd, passing 7º.3 South of Psc (Omega Piscium, mag. +4.0), located at the Southern Fish's tail, on February 7th. The planet crossed to the North of the celestial equator on February 8th, when its declination changed from negative to positive.

In early February Venus was joined by Mercury approaching from the West, in the second paired apparition of the 2019-20 evening apparition. This particular apparition of Mercury favoured Northern hemisphere observers, since from here the ecliptic presents a steep angle to the Western horizon after sunset at this time of year. On this occasion the two planets did not reach conjunction; they came closest on February 9th, when they were a significant 23°.6 apart. Mercury (mag. -0.5) reached greatest elongation East (18°.1) in neighbouring Aquarius on February 10th, positioned 23º to the WSW of Venus. The pairing continued through to about February 17th, when Mercury (having faded to mag. +0.9) headed into the dusk twilight.

On February 14th at 0340 UT Venus came to within 4'.5 (0º.07) of the Piscean border with Cetus, the Whale (or Sea Monster), an appropriately large constellation located to the South-east of Pisces. At 0750 UT on the same day Venus was positioned at precisely 1.0000 AU from the Earth, i.e. the same distance as the average distance of the Earth from the Sun (149.5 million kms or 92.9 million statute miles). At this point in the apparition the distance between Venus and the Earth was reducing at an average rate of about 1.032 million kms (641,300 statute miles) per day.

On February 15th Venus crossed the ecliptic Northwards, then on February 19th passed 2°.0 South of the star Psc (Delta Piscium, mag. +4.4). Four days later (23rd) the planet passed 34' (0°.56) South of Psc (Epsilon Piscium, mag. +4.2). On old star maps these stars mark a section of the meandering cord which ties the Northern and Southern Fishes' tails together.

Gibbous Venus at 62% phase filmed by the writer during the planet's evening apparition in 2004 (click on the thumbnail for the full-size animation, 163 KB). The unsteady 'boiling' effect of the planet is caused by turbulence in the Earth's atmosphere. In the 2019-20 apparition Venus attained a 62% phase on March 2nd 2020.

Positioned 2°.7 to the East of Psc is the double star Revati ( Psc or Zeta Piscium,, mag. +4.9), a Sanskrit name adopted by the IAU in 2017 and derived from an ancient Hindu lunar mansion. Venus passed 1°.0 North of Revati on February 25th. The star comprises two components of magnitude +5.2 and +6.3, separated by a wide 23" (0'.4) and easily split in small telescopes. The fainter component is located at a position angle (bearing from Celestial North) of 63° (roughly in the '10 o'clock' position). Venus passed 4°.5 South of the star Alpherg ( Psc or Eta Piscium, mag. +3.8), which marks the Northern Fishes' tail, on February 29th. Alpherg is the brightest star in Pisces, a yellow giant which serves as a convenient 'finder star' for the galaxy M74 (NGC 628), positioned just 1°.3 to its ENE. M74 is a 10th-magnitude face-on spiral and is one of the faintest objects in the Messier catalogue.

By late February Venus had brightened slightly to magnitude -4.1, its apparent diameter was approaching 20" and its illuminated phase was a little over 60%.

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On March 4th Venus passed 3°.2 North of the star Torcular ( Psc or Omicron Piscium, mag. +4.2), positioned close to the Piscean boundary with Aries, the Ram. The name was formerly standardized by the IAU in 2017, the original name having been Torcularis Septentrionalis. Later that same day, Venus entered Aries. Venus' passage through this small constellation would be an eventful one, involving a planetary conjunction, a significant orbital position passage and a maximum solar elongation.

On March 6th Venus passed 7°.3 South of the multiple star Sheratan ( Ari or Beta Arietis, mag. +2.6), then on March 9th the planet was in conjunction with Uranus, passing 2°.4 to the North of the blue-green planet at 1430 UT. Uranus re-entered Aries from Pisces in the previous year, having spent almost nine years in the latter constellation. This conjunction had the same problem as that for Neptune six weeks earlier: namely, the brilliance of Venus confounding the ease of viewing. In this case the problem was somewhat less since Venus shone at a magnitude of -4.1 whilst Uranus was a much more comfortable +5.8.

Four hours after the planetary conjunction, Venus passed 8°.5 South of the Ram's brightest star Hamal ( Ari or Alpha Arietis, mag. +2.0), which in 2011 was found to have an extra-solar planet or exoplanet (a planet outside our own Solar System) orbiting around it. The exoplanet is the equivalent of 1.7 Jupiter masses and orbits the star at a distance of 1.1 AU in a period of 380 days. Hamal is the brightest of six stars in Aries which are known to host an exoplanet.

Venus passed the perihelion point in its orbit (its closest point to the Sun) in the early hours (UT) of March 20th, at a solar distance of 0.7184 AU (107.4 million kms or 66.7 million statute miles). The planet's passage through perihelion at this moment in time was significant for Northern hemisphere observers for a reason which will be explained shortly. Later that same day Venus passed 8º.0 South of the star Bharani (41 Ari or 41 Arietis, mag. +3.6), another name which was adopted by the IAU in 2017. Bharani is the second lunar mansion in Hindu astrology. Two degrees to the NNW of Bharani, in the Northernmost realm of Aries, is the star Lilii Borea (39 Ari or 39 Arietis, mag. +4.5), a Latin name meaning 'Northern Lily'. The name was formally recognised by the IAU in 2017 and it first appeared in a 1757 star catalogue compiled by the French astronomer Nicolas-Louis de Lacaille (1713-1762). The lily to which he referred was the short-lived constellation Lilium, the Lily, a fleur-de-lis placed in this part of the sky by another Frenchman, Ignace-Gaston Pardies (1636–1673), in honour of King Louis XIV.

On March 22nd Venus passed 1º.3 South of Ari (Epsilon Arietis, mag. +4.6) which is both a double star and a variable star. At around 15 hours UT on the following day (23rd) the distance between the Earth and Venus was the same as that between the Sun and Venus, at 0.7184 AU (107.4 million kms or 66.7 million miles). Seen from far above the Earth's North pole, the Earth, Venus and the Sun now appeared to form an isoscelene triangle in space, with Venus positioned at the apex.

In mid-March observers in Equatorial latitudes saw Venus attain its highest altitude above the local horizon for the 2019-20 apparition, the planet being 31° high in the WNW at 30 minutes after sunset (the scenario is shown in the form of a horizon diagram below). At these latitudes, the planet now remained visible for almost three hours after sunset. At latitudes South of the Southern Tropics the planet's altitude at any given period after sunset had reduced considerably since the optimal period in December. At latitude 35º South Venus was only 14º above the horizon at one half-hour after sunset, being visible for less than 2 hours whilst at 45º South the planet stood just 7º high at 30 minutes after sunset, being visible for 1½ hours thereafter.

Venus reached its greatest elongation from the Sun for this apparition (46°.08 East) on March 24th in Eastern Aries, positioned roughly mid-way between the stars Ari and Botein ( Ari or Delta Arietis, mag. +4.3). At this stage, telescopes showed Venus' disk half-illuminated (phase = 0.50 or 50%), which is often referred to as the moment of dichotomy. The planet now had an apparent diameter of  23".3 and shone an magnitude -4.2. Although the greatest elongation from the Sun occurred on March 24th, Venus was in fact positioned at precisely 46°.0 elongation for a 13-day period from March 18th through to March 31st. When seen from a point far above the Solar System, the Earth, Venus and the Sun now formed a right-angled triangle in space, with Venus positioned at the 90° angle.

On the same day as Venus reached greatest Eastern elongation, Mercury - now on the opposite side of the Sun in central Aquarius - reached greatest Western elongation (27°.7) in the morning sky.

For a few days around greatest elongation, telescopic observers often attempt to determine the precise date of dichotomy. It is the moment when the terminator (the line separating the light and dark sides of the planet) appears perfectly straight, essentially dividing Venus into two perfect halves. Solar System geometry suggests that this should occur on greatest elongation day, however it often does not and the precise reason for this was not understood until quite recently. Observers often report the straight terminator a few days earlier or later than the greatest elongation date (early in evening apparitions and late in morning apparitions). Hence in the 2019-20 apparition, telescopic observers could expect to see a 50% phase on or around March 21st. This is commonly known as the phase anomaly or Schröter's Effect (the latter named after the German astronomer Johann Schröter, who first observed the effect in 1793). The phenomenon is thought to be due to Venus' dense atmosphere scattering the sunlight. Blue light scatters more readily than red light (which is why the sky on Earth appears blue) and this effect is also seen on Venus when it is observed using coloured eyepiece filters. The phase anomaly is much more evident when the planet is observed through a blue filter, whilst the anomaly is less evident when seen through filters of other colours, e.g. red or yellow.

Venus at Dichotomy imaged by Manos Kardasis (Athens, Greece) on January 13th 2017 using a 14-inch (355 mm) Schmidt-Cassegrain telescope (click on the thumbnail for a larger image, 4 KB). Note the 'cusp collars' at the planet's polar regions, apparently deforming an otherwise straight terminator (Image: ALPO-Japan / Manos Kardasis)

For Northern hemisphere observers the date of Venus' maximum solar elongation in 2020 was ideal, since it coincided with the period during which the planet attained its highest position above the local horizon after sunset. From late March into early April, for example, observers at latitude 30° North saw the planet attain a significant 38° above the Western horizon at 30 minutes after sunset - the highest altitude attained from any latitude during the 2019-20 apparition. Higher latitudes did not fare much worse. Even from latitude 60° North, in late March, the planet was placed 32° above the Western horizon at 30 minutes after sunset. This ideal set of circumstances meant that Venus remained visible after sunset for between 3½ hours (at 30° North) and 5½ hours (at 60° North). In addition, Venus' passage through perihelion only a few days earlier meant that it was slightly brighter than normal at this point. Hence for Northern hemisphere observers the planet was both high and bright - the best combination of circumstances in eight years - making naked-eye observation particularly favourable.

For the naked-eye planet observer situated at mid- and high-Northern latitudes, Venus' 2019-20 apparition was the best evening apparition in the planet's apparition 'cycle' (there being five evening and five morning apparitions in each Venusian 8-year 'Cycle'). In contrast, for Equatorial and Southern hemisphere observers it was the worst evening apparition in the 'cycle'. For telescopic observers of the planet, however, the relatively high placement of Venus in the sky after sunset was of little benefit. Because of the planet's glare when seen against a darkening sky, coupled with the Earth's troublesome atmospheric turbulence at low altitudes, most experienced telescope users observe the planet in full daylight, when it is high above the horizon and more easily seen against a brighter sky. Of course, extreme caution must be taken when attempting to observe any of the planets in daylight and the Sun must be positioned at a safe angular distance from the planet and be fully shielded from view.

On March 25th Venus passed 1°.3 North of the aforementioned Botein, the Easternmost star of the Ram figure. The planet entered Taurus, the Bull, on March 30th, where it would remain through to the end of the apparition.

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Greatest elongation day having passed, Venus began to show a crescent phase through telescopes, its apparent size continuing to enlarge slightly with each passing day. From April 3rd to 4th the planet passed South of the open star cluster known as the Pleiades or M45. Also known by the name The Seven Sisters, they are probably the best-known star cluster in the night sky. Under dark skies the seven brightest stars in the group can be seen with the naked-eye; they are Alcyone ( Tauri or Eta Tauri, mag. +2.9), Atlas (mag. +3.6), Electra (mag. +3.7), Merope (mag. +4.2), Taygete (mag. +4.3), Pleione (mag. +5.1v) and Celaeno (mag. +5.5). Venus took a little over a day to traverse the apparent width of the cluster, passing 27' (0°.45) South of Electra (the Westernmost naked-eye star of the group) at 0610 UT on April 3rd and, 27 hours later, 5' (0°.08) South of Atlas (the Easternmost naked-eye star of the group) at 0930 UT on April 4th.

On April 7th Venus passed 12°.2 North of the eclipsing binary star Tau (Lambda Tauri), positioned at the 'chest' of the Bull figure, whose magnitude varies from ca. 3.5 to 4.0 over a period of four days.

From April 12th to April 17th Venus passed to the North of the large V-shaped star cluster known as the Hyades. The cluster comprises around 400 stars spread over an exceptionally large area of about 5° of the sky. On April 12th Venus passed 10°.2 North of the star Prima Hyadum ( Tau or Gamma Tauri, mag. +3.6), positioned at the apex of the 'V'. Before standardization by the IAU, the star was known variously as Primus Hyadum or Hyadum I. On April 13th Venus passed 8°.5 North of Secunda Hyadum (¹ Tau or Delta-1 Tauri, mag. +3.7), a triple star system positioned about half-way along the Northern arm of the Hyades cluster. Before IAU standardization the star was also known as Secundus Hyadum or Hyadum II.

Also positioned along the Northern arm is the star Ain ( Tau or Epsilon Tauri, mag. +3.5), marking the base of the Bull's Northern horn. Venus passed 7°.2 North of the star on April 15th. At the same moment the planet passed 10°.5 North of Chamukuy (² Tau or Theta-2 Tauri, mag. +3.7), positioned about half-way along the Southern arm of the cluster. The name is that of a small bird in Yucatec Mayan culture and it was adopted by the IAU in 2017. The star forms a naked-eye yellow-white double with ¹ Tau (Theta-1 Tauri, mag. +3.8), positioned some 5'.6 (0°.09) to the North.

On April 17th Venus passed 10°.2 North of Taurus' brightest star Aldebaran ( Tauri, mag. +0.9), positioned at the South-eastern corner of the 'V' and marking the 'eye' of the Bull. Aldebaran appears orange-red to the naked-eye since it is a red giant star. It appears to be part of the cluster but in fact, it is not a physical member of the Hyades group; its appearance in the cluster is purely a line-of-sight effect. The Hyades lie at a distance of about 150 light years from Earth whereas Aldebaran is much closer, at 68 light years.

Venus passed 4°.0 North of the star Tau (Tau Tauri, mag. +4.2) on April 19th, another star which is not part of the Hyades group. Positioned at the 'bend' of the Bull's Northern horn, it is a multiple-star system and a member of an obscure open star cluster known as Alessi 51.

As Venus proceeded towards the North-eastern corner of Taurus, its apparent motion against the background stars was slowing. When the planet entered Taurus in late March its apparent motion was about 1° per day but by the close of April its daily motion had slowed to around 0°.5. The solar elongation was also narrowing, having reduced from 46° in late March to around 40° by late April.

Venus attained its greatest brilliancy for this apparition (mag. -4.4) on April 28th in North-eastern Taurus. Greatest brilliancy occurs when the percentage of the illuminated portion of the disk (phase) and its angular size combine to best visual effect. In 2020 this took place when the planet was 27% illuminated (phase = 0.27), its angular diameter was 37".3 and its solar elongation was 39°. Thirty minutes after sunset, naked-eye observers in the Northern hemisphere now saw Venus in its true majestic brilliance against a dark sky, positioned some 30° high above the Western horizon. For much of the Southern hemisphere, Venus was brilliant and the sky was dark, but the planet was less than 20° above the horizon at 30 minutes after sunset.

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On May 4th Venus attained its most Northerly declination for this apparition at +27° 49' 1" (+27°.82) which was the most Northerly declination attained by the planet since May 2012 and before the year 2077. The planet was now 4°.7 North of the ecliptic (ecliptic latitude = +4°.7) and only 0°.9 South of Taurus' boundary with Auriga, the Charioteer. Across the world, the planet now set at its most Northerly point along the local horizon. Its Eastward motion against the background stars had now slowed to just 0°.3 per day.

Venus' solar elongation fell below 30° East on May 12th. The planet's apparent motion ceased on May 13th as it reached its Eastern stationary point, positioned 1°.5 South-west of the star Alnath ( Tau or Beta Tauri, mag. +1.7), which marks the tip of the Bull's Northern horn. Hereafter Venus moved retrograde against the background stars, its declination (and ecliptic latitude) reducing as it accelerated towards the close of the apparition.

After reaching peak brilliancy in late April, Venus faded rapidly as May progressed: it began the month at magnitude -4.3 and would end the month at magnitude -3.8. From around mid-May, steadily-held binoculars began to detect Venus as a tiny crescent soon after sunset as the planet languished low in the WNW sky. Telescopes showed a large, thin crescent at this point, around 10% illuminated and nearly 50" in diameter. The crescent appeared greatly disturbed by the Earth's turbulent atmosphere and was split into the rainbow colours by an effect called dispersion (an example of how dispersion appears through a telescope can be seen here).

A 'Bow-like Venus' at Dusk imaged by Tomio Akutsu (Tochigi Prefecture, Japan) on March 16th 2017 using a 14-inch (355 mm) Schmidt-Cassegrain telescope (click on the thumbnail for a larger image, 3 KB). The planet was 17° East of the Sun with a 4% illuminated crescent (Image: ALPO-Japan / Tomio Akutsu)

With Venus retrograding towards the South-west at a rate of just 0°.2 per day, it was joined again by Mercury in mid-May in the third and final paired apparition of the 2019-20 evening apparition. The orange-pink planet moved swiftly into the evening sky, speeding North-westwards towards Venus at a rate of 2°.1 per day. This was Mercury's second evening apparition of 2020 and its third overall (there having been a morning apparition in-between). This particular apparition favoured Northern hemisphere observers although the altitude of both planets after sunset was rather low from all except Equatorial and Northern Tropical latitudes. At midnight UT Mercury was positioned 9°.2 WSW of Venus on May 18th, 7°.1 WSW of Venus on the 19th, 5°.0 WSW of it on the 20th, 3°.0 WSW of it on the 21st and 1°.2 South-west of it on the 22nd. Over this period Mercury faded by about 0.1 magnitude per day from -0.9 (on May 18th) to -0.5 (on May 22nd). At 0753 UT on May 22nd Mercury passed 0°.9 South of Venus in the sixth and final planetary apparition of the 2019-20 apparition. The waxing crescent Moon passed South of the pair on May 23rd and 24th, Mercury becoming lost from view from about May 28th.

Venus' elongation was now rapidly reducing, falling from 20° East of the Sun on May 21st to 15° East of the Sun on May 25th. As the Venusian crescent continued to enlarge it also became more slender, such that the dark (non-illuminated) side of the planet was well-displayed when seen from the Earth. Telescopic observers now began their search for the mysterious and elusive Ashen Light, a faint glowing of the night side of Venus which until recently had no clear explanation. First observed in 1643 by the Italian astronomer Giovanni Riccioli (1598-1671), the effect is best observed when Venus is at a narrow crescent phase and is seen against a fully dark sky. Observers searching for the Light will normally use ultraviolet and/or infrared filters in order to help reveal it, an occulting bar often being used to block the bright, visually-intrusive crescent from view. The phenomenon is believed to be caused either by the planet's surface glowing red hot (due to its extremely high surface temperature) or due to electrical activity in its dense atmosphere.

In the final week of May, keen observers saw Venus positioned only a few degrees above the horizon at dusk, the stars around it no longer visible in the bright twilight. Those with exceptionally-good eyesight may now have attempted to observe the crescent of Venus with the naked-eye. Whilst this may seem extraordinary, the planet's apparent size of around 57" brought it very close to the generally-accepted resolution of the human eye, i.e. 1 arcminute. Because the planet's solar elongation was now less than 15° glare was no longer a problem because the planet was seen in bright twilight through to its setting, theoretically allowing the crescent to be discerned more easily.

By the end of May Venus became lost from view from all locations as it sped towards inferior conjunction (passing between the Earth and the Sun) on June 3rd. Positioned 0°.5 to the North of the Sun in central Northern Taurus, Venus passed unseen from the evening sky into the morning sky. The period of non-visibility was brief, however, since after the first week of June the planet was seen rising as a 'Morning Star' in the Eastern sky shortly before the Sun, heralding a new morning apparition (2020-21) which lasted through to February 2021.

 [Terms in yellow italics are explained in greater detail in an associated article describing planetary movements in the night sky.]

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Venus Conjunctions with other Planets

in 2019-20

The Venus and Jupiter conjunction of November 24th 2019 was the most visually spectacular of the six planetary conjunctions visible during the period, although the two were not ideally placed for viewing at higher Northern latitudes - indeed, it was not visible at all North of about 57° North. From latitude 50° North the pair were positioned just 8° above the South-western horizon as Jupiter came into view, being visible for a little over an hour thereafter. From latitudes North of about 45° North the planets were seen to set in twilight; further South, they set in darkness. Elsewhere the altitudes and directions of the planetary pair as Jupiter came into view were as follows: 15° high in the South-west (at 30° North), 22° high in the WSW (at the Equator) and 20° high in the WSW (at 35° South), the planets being visible for 1½ hours, 1¾ hours and 1¾ hours respectively. Adding interest to the event was Saturn, a pale yellow moderately bright 'star' positioned 19° further to the East.

For Northern hemisphere observers the placement of both Jupiter and Saturn in Sagittarius during the period meant that both of these planetary conjunctions were positioned at low altitude in the South-western sky at dusk. Venus and Saturn were in conjunction on December 11th 2019, when they were 1°.8 apart at a respectable 30° East of the Sun. The event was visible worldwide, although it was seen in continuous twilight North of about latitude 55° North. From 40° North the pair were positioned 17° above the South-western horizon as Saturn came into view in the dusk, being visible for almost two hours thereafter. Elsewhere the planets were 27° high in the WSW (at the Equator), 25° high in the WSW (at 25° South) and 18° high in the WSW (at 45° South). The conjunction was visible for two hours, two hours and 1¾ hours, respectively.

The placement of Uranus (in Aries) and Neptune (in Aquarius) meant that their evening visibility favoured Northern hemisphere observers. The Venus-Neptune conjunction of January 27th 2020 was the closest conjunction of the six, the planets being just 4' (0°.06) apart and easily contained within the eyepiece view of a small telescope. The altitudes of the planets as Neptune came into view were as follows: 17° high at 60° North, 29° high at 30° North and the Equator, 19° high at 25° South and 7° high at 45° South. The Venus-Uranus conjunction of March 9th 2020 was technically the best conjunction of the six for Northern hemisphere observers, the event taking place only two weeks ahead of Venus' greatest elongation date with the pair being positioned 45° East of the Sun. The separation between the two planets was a wide 2°.4 degrees - equivalent to almost five apparent Full Moon diameters. For Northern hemisphere observers the altitudes of the Venus-Uranus conjunction were higher than those for the Venus-Neptune conjunction: 27° high at 60° North, 36° high at 30° North and 31° high at the Equator. Altitudes in the Southern hemisphere were about the same as those for the Neptune conjunction. In both cases the planets set in darkness from all but higher Southern latitudes.

There were two visible conjunctions between Venus and Mercury during the 2019-20 apparition. The first, on October 30th 2019, took place early in the apparition when observers at higher Northern latitudes had not yet begun to see Venus emerge in the dusk sky. The widely-separated pair were however ideally placed for Southern hemisphere observers. From the Equator Southwards the two planets were 16°-17° high in the WSW (Southern Tropical latitudes) or West (mid-Southern latitudes) as Mercury came into view, the pair being visible for between 1¼ hours (15° South) and 1½ hours (45° South) before setting in darkness.

The second Venus-Mercury conjunction, on May 22nd 2020, took place late in the apparition when observers were only days away from losing sight of Venus. The narrow solar elongation of 18° meant that the planets were seen in twilight throughout from locations North of about 35° North and South of about 10° South. At 0°.9 separation it was a relatively close approach between the two planets, Mercury speeding past Venus as the latter planet crawled slowly in the opposite direction against the background stars. From latitude 60° North the planetary pair were 8° high in the North-west as Mercury came into view, the pair being visible for 1¾ hours thereafter. At 30° North they were 15° high in the WNW and visible for 1¼ hours. At the Equator - where the planets set in darkness - they were also 15° high in the WNW and visible for about an hour. South of the Equator the altitudes were lower, the directions more Northerly and the visibility durations shorter: 10° high in the North-west and visible for around 50 minutes (at 25° South) and just 4° high in the North-west, visible for around 30 minutes (at 45° South).

The six planetary conjunctions with Venus which were viewable during the 2019-20 evening apparition are summarised in the table below.

Venus conjunctions with other planets during the 2019-20 evening apparition (click on the thumbnail for the full-size table, 50 KB) The column headed 'UT' is the Universal Time (equivalent to GMT) of the conjunction (in hrs : mins). The separation (column 'Sep') is the angular distance between the two planets, measured relative to Venus, e.g. on 2019 Dec 11, Saturn was positioned 1°.8 North of Venus at the time shown. The 'Fav. Hem' column shows the Hemisphere in which the conjunction was best observed (Northern, Southern and/or Equatorial). The expression 'Not high N/S Lats' indicates that observers at latitudes further North than about 45°N (or further South than about 45° South) were likely to have found the conjunction difficult or impossible to observe because of low altitude and/or bright twilight.

In the 'When Visible' column, a distinction is made between Dusk and Evening visibility; the term Dusk refers specifically to the twilight period after sunset, whilst the term Evening refers to the period after darkness falls (some conjunctions take place in darkness, others do not, depending upon latitude). The 'Con' column shows the constellation in which the planets were positioned at the time of the conjunction.

To find the direction in which the conjunctions were seen on any of the dates in the table, note down the constellation in which the planets were located ('Con' column) on the required date and find the constellation's setting direction for your particular latitude in the Rise-Set direction table.

The table is modified from another showing Venus conjunctions with other planets from 2015 to 2020 on the Venus Conjunctions page.

Although any given conjunction takes place at a particular instant in time, it is worth pointing out that, because of the planets' relatively slow daily motions, such events are interesting to observe for several days both before and after the actual conjunction date.

There are in fact two methods of defining a planetary conjunction date: one is measured in Right Ascension (i.e. perpendicular to the celestial equator) and the other is measured along the ecliptic, which is inclined at 23½° to the Earth's equatorial plane (this is due to the tilt of the Earth's axis in space). An animation showing how conjunction dates are determined by each method can be found on the Jupiter-Uranus 2010-11 triple conjunction page. Although conjunction dates measured along the ecliptic are technically more accurate (separations between planets can be significantly closer) the Right Ascension method is the more commonly used, and it is the one which is adopted here.

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Moon near Venus Dates,

September 2019 to May 2020

The Moon is easy to find, and on one or two days in each month, it passes Venus in the sky. Use the following tables to see on which dates the Moon passed near the planet between September 2019 and May 2020:

The Moon moves relatively quickly against the background stars in an Eastward direction, at about its own angular width (0º.5) each hour (about 12º.2 per day). Because it is relatively close to the Earth, an effect called parallax causes it to appear in a slightly different position (against the background stars) when seen from any two locations on the globe at any given instant; the further apart the locations, the greater the Moon's apparent displacement against the background stars. Therefore, for any given date and time listed in the table, the Moon will have appeared closer to Venus when seen from some locations than others. For this reason, the dates shown in the table should be used only for general guidance.

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Direction, Altitude & Visibility Duration

of Venus after Sunset,

October 2019 to May 2020

The following tables give the direction and altitude (angle above the horizon) of Venus at 30 minutes after sunset, together with the duration of visibility of the planet after sunset, for the 2019-20 evening apparition. An explanation of abbreviations in the tables is given in the box below. For the sake of convenience, the table is split into Northern and Southern hemisphere latitudes (the Equator is included in both tables to allow interpolation of the data for observers situated at Equatorial latitudes). The tables should have proved sufficient to locate the planet in twilight, allowing telescope users to view the planet in comfort (because of Venus' brilliance, glare becomes a problem when the planet is seen through the eyepiece against a dark sky). Direction and Altitude diagrams are also provided below for intermediate latitudes of 55° North, 35° North, 30° South and the Equator.

The tables allow one to find the highest altitude in the sky which Venus attained for any given latitude during the 2019-20 evening apparition, and in which direction it was seen. For example, observers situated at latitude 50° North found the planet highest in the sky (at 30 minutes after sunset) in late March 2020, when it was seen at an altitude of 36° towards the West. The duration column shows that the planet was then above the horizon for about 4½ hours after sunset.

Direction & Altitude (30 minutes after local sunset) and Visible Duration of Venus for Northern hemisphere latitudes and the Equator for the evening apparition of 2019-20 (click on the thumbnail for the full-size table, 105 KB; for Southern hemisphere latitudes and the Equator, click here, 95 KB). To find your latitude, visit the Heavens Above website, select your country and enter the name of your nearest town or city in the search box.

The table column headings are as follows:

Dir = compass direction of Venus,

Alt = angular altitude (elevation) of Venus (degrees above the horizon; a negative value of Alt means Venus was below the horizon). Altitudes are accurate to within ±1°.

Dur = the approximate visibility duration of Venus after local sunset (in hrs:mins). An italicised duration means that Venus was seen under twilight conditions through to its setting, i.e. it  was not seen against a truly dark sky (twilight in this case refers to nautical twilight, which ends when the Sun is more than 12° below the horizon). Durations are accurate to within ±5 minutes.

Note that the directions and altitudes refer to the planet's position at 30 minutes after local sunset. To find the time of local sunset at your own location, select your country/town from the drop-down menu at the TimeandDate.com website. The approximate time at which Venus set can be found by adding the visibility duration on a particular date (column Dur) to the time of local sunset on the same date. To find the direction in which Venus set on any given date for a particular latitude, note down the constellation in which the planet was located on the required date (column headed Con) then find its setting direction for your latitude in the Rise-Set direction table.

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Direction & Altitude Diagrams (Horizon Diagrams)

for the 2019-20 Evening Apparition

The following diagrams show an observer's Western horizon (from due South to due North) for latitudes of 55° North (a high-Northern latitude), 35° North (mid-Northern), the Equator and 30° South (mid-Southern). The path of Venus is plotted in the sky at 30 minutes after local sunset throughout the 2019-20 evening apparition with the planet's direction and altitude marked along the horizontal and vertical axes, respectively. Essentially, these diagrams show the same information as in the above look-up tables, but in an illustrative format, for the Equator and three intermediate latitudes.

Below:  Paths of Venus in the Evening Sky (30 mins after sunset) for the 2019-20 evening apparition, as seen by observers at latitudes 55° North, 35° North, the Equator and 30° South (click on a thumbnail for a full-size image, ca. 130 KB each). The letters GE refer to the planet's greatest elongation (followed in brackets by its angular distance from the Sun) and the letters GB refer to the planet's greatest brilliance (followed in brackets by its apparent magnitude).

The azimuth (Az, along the bottom of each diagram) is the bearing measured clockwise from True North (where 0° = North, 90° = East, 180° = South, etc.). The altitude (Alt) is the angle measured vertically from the local horizon (the horizon itself is 0° and the point directly overhead is 90°). Azimuth and altitude are co-ordinates which are used for high-accuracy tracking of objects across the sky; in astronomy it is mainly used for setting telescopes which are fitted with altazimuth mounts.

To determine the planet's position in the sky with higher accuracy, an overlay grid is provided for each diagram. The overlay grids are marked at 10° intervals in azimuth and altitude (the dates are removed for clarity). For example, at latitude 35° North on February 1st 2020, at 30 minutes after sunset, Venus was found at azimuth = 239° (i.e. in the WSW) and altitude = 30°. Azimuths and altitudes are accurate to ±1°.

Although the dates indicated in the above diagrams refer specifically to the period 2019-20, Venus has an 8-year cycle of apparitions such that its position in the evening sky in 2019-20 will repeat very closely in the evening sky of 2027-28. The writer refers to this particular evening apparition as Apparition C1; for more details, see the accompanying article describing The Venus 8-year Cycle.

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Credits

• The star chart was created using by the commercial software MegaStar by Willmann-Bell, Inc. Star colours were based on those shown in "Patrick Moore's Colour Star Atlas" (Mitchell Beazley Publishers Ltd., London, 1973).
• The dates of the planet's constellation boundary crossings and its directions, altitudes and visibility durations were determined from the commercial software RedShift 5 by Maris Technologies Ltd. The times and separations of the lunar conjunctions with Venus (Moon near Venus dates) were obtained from the same software using the 'Conjunctions' option of the 'Sky Diary'.
• The distances of Venus, its aphelion and perihelion dates and the daily rates of angular motion were derived from the SkyGazer Ephemeris utility by John Biondo.
• The future dates of stellar occultations by Venus were obtained from the website The Sky and Its Phenomena by Italian amateur astronomer Pierpaolo Ricci. The most Northerly and Southerly declinations of the planet during the apparition were obtained from his Extreme Declinations page.

• Information on the cultural origins of the IAU's 'newly-named' stars were obtained from the following sources: Revati, Bharani, Chamukuy and Larawag: UniverseToday.com. Paikauhale and Guniibuu: IAU's WGSN FAQ page. Lilii Borea: Ian Ridpath's Star Tales website, with supplementary information from Wikipedia.
• The zodiac signs used in the data table are courtesy of the free graphics site .

Copyright  Martin J Powell  May 2019