Tag Archives: sky watching

2020, September 25: Morning Planets, Mars and Venus

Mars in Pisces, September 25, 2020
2020, September 25: Mars is nearly between Nu Piscium (ν Psc) and Omicron Piscium (ο Psc) is 0.9° above ν Psc and 2.8° below ο Psc.

Bright Mars and brilliant Venus put on an early morning display.

by Jeffrey L. Hunt

Just before 5 a.m. CDT, bright Mars was high in the southwest.  It is among the dim stars of Pisces. The Red Planet is slowly retrograding – moving westward compared to the starry background.  This illusion occurs when our faster moving planet approaches and passes the slower moving outer planets.

This morning, Mars is nearly between the stars Omicron Piscium (ο Psc on the photo) and Nu Piscium (ν Psc).  The planet is 0.9° above ν Psc and 2.8° below ο Psc.

Mars is closest to Earth on October 6.  As Earth approaches Mars, the Red Planet becomes brighter, but not much larger in appearance to the human eye.  While it can double in its apparent size through a telescope, the increase is imperceptible to the human eye (unlike what is shown in the social media memes.)

Earth moves between the sun and Mars on October 13.  This is called opposition, because the planets appear on opposite sides of Earth and their place and visible times are opposite of each other.

At opposition, a planet rises at sunset, appears in the south around midnight, and sets in the west

Venus in Leo, September 25, 2020
2020, September 25: Moving eastward in Leo, Venus is 4.8° to the upper left of Omicron Leonis (ο Leo).

At this hour, brilliant Venus is low in the east among the stars of Leo.  An hour later, about 90 minutes before sunrise, Venus is higher in the sky. 

At about 5 a.m. the famous constellation, Orion is in the south-southeast.  Orion’s larger hunting dog, Canis Major, with its bright star  Sirius is low in the southeast.

Among the stars Venus is moving eastward in Leo.  This morning it is 4.8° to the upper left of Omicron Leonis (ο Leo on the photo).  Watch Venus move farther away from ο Leo.  Early next month, Venus passes Regulus, the constellation’s brightest star.

Read more about the planets during September and October.

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Venus and Moon, September 14, 2020

2020, September 25: Morning Planets, Mars and Venus

Bright Mars and brilliant Venus put on an early morning display.

2020, September 25: Saturn and Moon

Saturn, Moon, Jupiter, September 25, 2020
September 25: One hour after sunset, the moon is 3.7° to the lower left of Saturn.

During early evening hours of September 25, the moon appears near Saturn in the southern sky.

by Jeffrey L. Hunt

During the evening hours of September 25, the moon appears 3.7° to the lower left of Saturn.  The gibbous moon is over 70% illuminated.

Jupiter, Saturn, Moon, September 25, 2020.
2020, September 25: The gibbous moon (overexposed in the photo) appears 3.7° to the lower left of Saturn. Jupiter is 7.6° to the lower right of Saturn.

Jupiter is 7.6° to the lower right of Saturn. 

As seen from the sun, Jupiter passes Saturn in a heliocentric conjunction on November 2. This is a prelude to the Great Conjunction on December 21, when Jupiter passes very closely to Saturn. While the planetary pair appears close in the sky, they are hundreds of millions of miles apart in space.

A Great Conjunction occurs every 19.6 years. The last one occurred in 2000. The next Jupiter – Saturn conjunction occurs October 31, 2040, when the two planets rise into the eastern morning sky. The gap is 1.1°. At this year’s conjunction, the two planets appear ten times closer.

While other conjunctions have occurred, this year’s conjunction is the closest Jupiter – Saturn conjunction since 1623.  That year’s conjunction occurred after the invention of the telescope and during very bright evening twilight.  Read our article about whether it was observed.

Read more about the planets during September and October.

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2020, September 24: Jupiter, Moon, Teapot

On September 24, the Moon visits the “Teapot” shape of Sagittarius with the moon nearby.

by Jeffrey L. Hunt

During the early evening of September 24, look in the south for the gibbous moon that is 60% illuminated.  Bright Jupiter is 4.2° to the upper left of the lunar orb. Dimmer Saturn is to Jupiter’s upper left.

Look carefully at the stars to the lower right of the gibbous moon.  They are the main stars of the constellation Sagittarius. The stars resemble a kitchen teapot.  The star Nunki, cataloged as Sigma Sagittarii (σ Sgr), is part of the Teapot’s handle.  Use a binocular, if necessary, to see the shape.

Jupiter is moving eastward compared to the starry background.  Saturn retrogrades, an illusion of moving westward that occurs when the faster moving Earth passes between the sun and the slower moving outer planets.

Next week, Saturn resumes its eastward motion as Jupiter continues to close the gap to the Ringed Wonder toward their Great Conjunction on December 21, 2020. This is the closest conjunction since the Jupiter – Saturn conjunction of 1623.  Great Conjunctions occur every 19.6 years, but this is the closest for nearly 400 years.

Here’s where the moon is on the next evening.

Read more about the planets during September and October.

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Full moon

2020, October 31: Rare Halloween Full Moon

A rare Halloween Full Moon, 76 years in the making, is visible across most of the planet in 2020. This could be called a “Blue Halloween Moon.”

2020, September 22: Equal Night Followed By Equal Light

Venus and Moon, September 14, 2020
2020, September 14: Through a hazy sky, the moon is 5.0° to the lower left of Venus.

The sun crosses the equator at 8:31 a.m. CDT to signal a change in astronomical seasons – the Autumnal Equinox.

by Jeffrey L. Hunt

Autumn begins in the northern hemisphere on September 22, 2020 at 8:31 a.m. CDT.  The sun’s light is most directed toward the equator and for the next six months aimed at the southern hemisphere.

In the northern hemisphere, the sun is lower in the sky and daylight is shorter.

On the day of the equinox, the sun rises east and sets in the west.

The word “equinox” is taken to mean “equal night.”  Daylight and nighttime are nearly equal at 12 hours.

Venus in morning sky, August 12, 2020
Venus in the morning sky.

Being a sky watcher, this writer, considers another date when daylight and darkness are equal.  In the northern hemisphere that occurs in late October.

Normally, we think of two segments of a 24-hour period, daylight and nighttime.  Day is when the sun is shining and night is when it is below the horizon.

Night, though, is made of two parts, twilight and darkness.  Twilight is that period of time – averaging about 90 minutes before sunrise and 90 minutes after sunset at the mid-latitudes – when the sky is illuminated, but it’s not dark.

When the sun is near the horizon, its possible to work outside and find your way around without artificial illumination. Crepuscular creatures wander from the tree line or fly about in the air.   

Crescent Moon, Venus, and Aldebaran, July 17, 2020
2020, July 17: The crescent moon, Brilliant Venus, and Aldebaran shine from the eastern during early morning twilight.

During mid-twilight, the brightest stars are visible. The sky is waxed with cobalt blues, golden yellows, and spectacular oranges.  A crescent moon may be visible just before sunrise or after sunset.  Venus dazzles the eye, and Mercury puts on rare performances.

Sometimes Jupiter plays tag with Venus or Mars is nearby, but the Red Planet is never at its greatest brightness when near Venus.

In the later stages of twilight, the horizon near the sun’s last rays continues to hang on to the final shreds of the sun’s glory.

Then darkness falls hard. The sky is ablaze with the night’s stars. The nocturnal animals prowl and the sky watchers gaze through their telescopes.

So, this writer looks beyond the equinox to the “equal light” days of late October when daylight and darkness are equal, at about 10.5 hours.

Take a look for the morning planets Venus and Mars before sunrise.  Jupiter and Saturn are in the south during the early evening.  Mars joins them before midnight.  Here is a summary of what’s happening with the planets during September.

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2020, September 18: Bright Morning Planets, Stars On Display

Mars in Pisces, September 18, 2020
2020, September 18: Mars, now slowly retrograding in dim Pisces, is 1.9° to the upper left of Nu Piscium (ν Psc) and 2.5° to the lower left of Omicron Piscium (ο Psc).

A clear sky this morning allowed brilliant Morning Star Venus and bright Mars to put on a planetary display before sunrise.

by Jeffrey L. Hunt

A north breeze that cleared smoke from the western wildfires revealed bright planets and bright stars.

At about 4 a.m. CDT, bright Mars was high in the south-southwest.  It is among the dim stars of Pisces. The Red Planet is slowly retrograding – moving westward compared to the starry background.  This illusion occurs when our faster moving planet approaches and passes the slower moving outer planets.

Mars is closest to Earth on October 6.  As Earth approaches Mars, the Red Planet becomes brighter, but not much larger in appearance to the human eye.  While it can double in its apparent size through a telescope, the increase is imperceptible to the human eye (unlike what is shown in the social media memes.)

Earth moves between the sun and Mars on October 13.  This is called opposition, because the planets appear on opposite sides of Earth and their place and visible times are opposite of each other.

At opposition, a planet rises at sunset, appears in the south around midnight, and sets in the west as the sun rises in the east.  Mars appears at opposition about every 26 months.

On the photo above, Mars appears 1.9° to the upper left of Nu Piscium (ν Psc on the photo) and 2.5° to the lower left of Omicron Piscium (ο Psc). 

Venus with bright stars, September 18, 2020
2020, September 18: Brilliant Morning Star Venus appears with Sirius, Procyon, Castor, Pollux, Betelgeuse and Rigel.

At this hour, brilliant Venus is low in the east.  An hour later, about 90 minutes before sunrise, the planet is higher in the sky. 

At this time Venus appears with other bright stars.  The night’s brightest star, Sirius, is low in the southeast. About a month ago, the star made its first appearance in the morning sky this year.

The famous constellation Orion – with its bright stars Betelgeuse and Rigel – are to the upper right of the Dog Star.

With a binocular the Orion Nebula, a stellar nursery – is visible as a hazy cloud.  The Little Dog Star – Procyon – is nearby.  The Gemini Twins – Castor and Pollux appear above Venus

Venus in Cancer, September 18, 2020
2020, September 18: Venus is in the east before sunrise. It is 1.4° to the lower left of Omicron Cancri (ο Cnc).

Among the stars Venus is moving eastward in the very dim starfield of Cancer.  This morning it is 1.4° to the lower left of Omicron Cancri (ο Cnc on the photo).  Watch Venus move farther away from ο Cnc.

Here is a daily summary about the planets during September.

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Venus and Jupiter, August 18, 2012

The Harvest Moon

The Harvest Moon is the full moon that occurs nearest to the autumnal equinox in the northern hemisphere.

2020, September 17: Jupiter, Saturn, International Space Station

The International Space Station passes Jupiter and Saturn, September 17, 2020
2020, September 17: The International Space Station passes Jupiter and Saturn during a 10-second time exposure. The planets are 8.0° apart.

After the sky cleared today, the International Space Station made a bright pass across the mid-northern latitude states this evening near Jupiter and Saturn in the sky.  The ISS was brighter than the planet Jupiter.

by Jeffrey L. Hunt

The International Space Station passes Jupiter and Saturn this evening as seen across the Midwest.  A clearing sky permitted viewing this evening.  At its brightest, the ISS was easily brighter than Jupiter.

As for the planets, Jupiter is 8.0° to the right of Saturn.  Jupiter passes Saturn in a Great Conjunction on December 21, 2020. This is the closest conjunction since the Jupiter – Saturn conjunction of 1623.  Great Conjunctions occur every 19.6 years, but this is the closest for nearly 400 years.

Before Jupiter passes Saturn in our sky, Jupiter edges past Saturn as viewed on the solar system’s scale in what is known as a heliocentric conjunction.  This occurs on November 2.

Continue to look for Jupiter and Saturn each evening.  During the next several weeks, watch Jupiter close the gap to Saturn.

Here is a daily summary about the planets during September.

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2020, September 13: Bright Jupiter Begins to Close on Saturn

Jupiter and Saturn in Sagittarius, September 13, 2020
2020, September 13: Saturn is 8.1° to the left of Jupiter. In the starfield, Jupiter is 2.1° to the lower left of Pi Sagittarii (π Sgr) and 2.9° to the lower right of 50 Sagittarii (50 Sgr). Saturn is 1.7° to the lower left of 56 Sagittarii (56 Sgr).


Jupiter’s retrograde ends and the Giant Planet begins to close on Saturn for the Great Conjunction of 2020.

by Jeffrey L. Hunt

Bright Jupiter and Saturn are in the south as the sky darkens from early evening twilight.

Jupiter is now moving eastward compared to the starry background, while Saturn retrogrades – moves westward compared to the stars – until month’s end.

This evening Jupiter is to the lower left of Pi Sagittarii (π Sgr on the photo above) and to the lower right of 50 Sagittarii (50 Sgr). 

Saturn is 8.1° to the left of bright Jupiter.  It is 1.7° to the lower left of 56 Sagittarii (56 Sgr).

The gap between Jupiter and Saturn begins to close until the Great Conjunction of 2020, when Jupiter seems to pass very close to Saturn in the evening sky.  This is the closest conjunction since the Jupiter – Saturn conjunction of 1623.  Great Conjunctions occur every 19.6 years, but this is the closest for nearly 400 years.

Before Jupiter passes Saturn in our sky, Jupiter edges past Saturn as viewed on the solar system’s scale in what is known as a heliocentric conjunction.  This occurs on November 2.

Continue to look for Jupiter and Saturn each evening.  During the next several weeks, watch Jupiter close the gap to Saturn.

Here is a daily summary about the planets during September.

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2020, November 2: Jupiter – Saturn Heliocentric Conjunction

A Jupiter-Saturn Heliocentric Conjunction, November 2, 2020
2020, November 2: Jupiter passes Saturn in a heliocentric conjunction, as viewed from outside the solar system.

As the Great Conjunction of Jupiter and Saturn nears, Jupiter passes Saturn if viewed from the sun.

by Jeffrey L. Hunt

As Jupiter edges closer to Saturn in the evening sky of Earth, Jupiter passes Saturn as viewed from outside the solar system on November 2, 2020.  This is known as a heliocentric conjunction.  The next one for these two planets is on December 7, 2040.

If we were on Jupiter on November 2, we would say that Saturn is at opposition.  Saturn is in the opposite direction in the sky from the sun.  If we were Saturnians, then we would say that Jupiter is at inferior conjunction, between Saturn and the sun. Notice on the chart above that Earth is not close to the line of the heliocentric conjunction.

From these two planets in alignment, a question may develop about more planets appearing in a line from the sun. Astronomer Jean Meeus (Mathematical Astronomy Morsels, pp. 186-191) addresses the question.  Without reciting his reasons, the answer: “Never!” The dynamics of fast – moving Mercury to slow-moving Pluto (Yes, Pluto is one of the “Classic Nine” planets.), there is never a moment when all nine are in a line stretching from the sun.  He further notes that it’s impossible for even three to be in a line.  Reasonably they can be within a 60° angle of each other, 50° if Pluto is not included.

Jupiter and Saturn in Sagittarius, November 2, 2020
2020, November 2: Jupiter is 5.0° to the lower right of Saturn, about one hour after sunset. Look toward the south-southwest.

In our sky, the planets are 5.0° apart.  They can be found in the south-southwest about an hour after sunset on November 2.  Saturn is to the upper left of bright Jupiter. The planets are in front of the stars of eastern Sagittarius.  The famous “Teapot” shape is to the lower right of the planets.

The Great Conjunction occurs December 21, 2020.

Continue to watch Jupiter and Saturn, as the Jovian Giant moves in and passes the Ringed Wonder as viewed from our observing spot on Earth.

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2020, October 31: Rare Halloween Full Moon

Halloween Art
2020: Halloween Full moon first since 1955 in Central Time Zone and since 1944 for North America. Photo Credit (https://www.publicdomainpictures.net/)

A rare Halloween Full Moon, 76 years in the making, is visible across most of the planet in 2020.

by Jeffrey L. Hunt

No, it’s not Comet Halley, but it’s been 76 years in the making, a Halloween Full Moon that is visible nearly across the entire globe.

During Halloween in 1944, a Full Moon occurred for nearly all the globe.  This was the last time a Halloween Full Moon was globally visible.

Many images of the season display cats with curved backs, leafless trees, ghosts, goblins, ravens, bats, and full moons (such as those on the accompanying graphic), but a Halloween Full Moon is a rare occurrence.

As the moon revolves through space, we view its sunlit surface in various shapes — the moon’s phases. We give them interesting names such as waxing gibbous or waning crescent.

Observers from half the globe can see the moon simultaneously. As Earth rotates and the moon rises higher into the sky. As it sets in one part of the globe, the moon rises in another part of the world.

No special equipment is needed to view this Full Moon. It is no different from any other full phase, except for the sentimentality of the date.

Because October has 31 days and a lunar cycle occurs every 29.5 days, a Halloween Full Moon means that the month’s first full moon occurs on October 1 or 2, depending on the time of the full phase.  It also marks the year’s Harvest Moon (October 1, 2020).

Because of the varied uses of the term “blue moon,” the Halloween Full Moon is the second of the month, and might be named a “Blue Halloween Full Moon.”

Many casual observers that see a bright moon might think that it’s full.  The moon might be gibbous or nearly full. Astronomically, the moon is full for an instant of time when it is opposite the sun from Earth.  During that night when the moon appears as a complete globe of light, we frequently use the “full moon” term.  Even a day before or after the actual date, the term is used.

For a reasonable discussion, let’s dig into the astronomical definition.  Further it is important to consider the observer’s location and time system (standard or daylight) that is used there.  Every place on Earth does not have the same clock time or even display the same date.  For example, during daylight time 1 p.m. in New York is 2 a.m. the next calendar day in Tokyo.  Because of the use of time zones, the fact that the earth is round, and not all places have daytime and nighttime simultaneously, tells us to make this distinction. A full moon may not occur on the same day for all earthly locations. To determine whether a Halloween Full Moon occurs, the local calendar must read October 31 and the full moon time must be from 12:00:01 a.m. to 11:59:59 p.m. local time.

Surveying U.S. Naval Observatory data from 1930 to 2050, the window occurs nearly every 19 years. Here are the Halloween Full Moons. Here is when recent Halloween Full Moons occurred:

  • 1944, October 31, 7:35 a.m. CST.  This was before Daylight Saving Time was used. The entire planet had a Halloween Full Moon
  • 1955, October 31, 12:04 a.m. CST.  There was no Halloween Full Moon for western North America and the Western Pacific to the International Date Line. All locations eastward to to the International Date Line had the Halloween Full Moon.
  • 2020, October 31, 9:49 a.m. CDT. All locations eastward to GMT+8 time zone with daylight time or GMT+9 hours with out daylight time.
  • 2039, October 31 (5:36 p.m. CST).  With the current public dislike for daylight time, the future of it is unpredictable. Standard time is used in this note.

In the Western Hemisphere, the year 2001 was a near miss for a Halloween Full Moon for North and South American time zones east of Mountain Time, and was the consequence of daylight time. It occurred November 1 (12:41 a.m. CDT). One cycle earlier, in 1982, the potential Halloween Full moon occurred nearly eight hours too late (November 1, 7:57 a.m. CDT) for North America and South America.  In 1974, another near miss occurred when the full moon occurred at 8:19 p.m. CDT on October 30.

The 2020 Halloween Full Moon is visible in North America and South America, and most of the globe, except for regions west of the International Date Line, such as Eastern and Central Australia, New Zealand, Papua New Guinea, Guam, and eastern Russia. The Halloween Full Moon occurs in all time zones eastward from the Prime Meridian through Europe, Africa, Asia, India, Indonesia, Korea, and Japan to western Australia. It occurs eastward to GMT+8 hours, with daylight time and GMT+9 hours for countires without daylight time. For regions to the east of these time zones, the Full Moon occurs there during the early morning hours of November 1. 

The next Halloween Full moon is during 2039 in North America and South America. Depending on the regional status of the use of daylight time, possibly two time zones east of the Greenwich, England meridian can witness a Halloween Full Moon. It’ll occur before Comet Halley’s return in 2061. So “celebrate” this year’s Halloween Full Moon!

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2020, September 14: Venus, Moon Visit Beehive

Venus and Moon, September 14, 2020
2020, September 14: Ninety minutes before sunrise, look for the moon and Venus near the Beehive star cluster. The moon is 5.0° to the lower left of Venus.

The crescent moon and Morning Star Venus pass close to the Beehive star cluster.

by Jeffrey L. Hunt

Moving among the dim stars of Cancer, brilliant Morning Star Venus passes the Beehive star cluster during mid-September.

Venus and Moon, September 14, 2020
2020, September 14: Through a hazy sky, the moon is 5.0° to the lower left of Venus.

Venus has appeared in the morning sky since mid-June, and it is there into the new year.  It continues to step eastward compared to the starry background in its morning sojourn.

The planet continues to rise over 3.5 hours before sunrise.  By the beginning of morning twilight that starts about 100 minutes before sunrise, Venus sparkles above the skyline in the eastern sky.  Like the other easily visible planets, Venus appears as an overly bright star, the brightest “star” in the sky.  It even outshines Sirius, nighttime’s brightest star.

Venus and Moon, September 14, 2020
2020, September 14: The moon is 5.0° to the lower left of Venus.

All the planets appear to move along the ecliptic, an imaginary line that is the plane of the solar system.  The ecliptic makes a great circle around the sky through the familiar zodiacal constellations. Mars, shining in the southern sky during morning twilight, is among the stars of Pisces, while evening planets Jupiter and Saturn are in eastern Sagittarius.

Cancer is a dim constellation between the Gemini Twins and Leo, where Venus moves at month’s end.

The Beehive star cluster is a distant clump of stars that are similar to the famous Pleiades (Seven Sisters), but they are farther away, appearing dimmer to our eyes.  The cluster is also known as the Praesepe (Manger).

The Beehive star cluster looks like a fuzzy cloud to the unaided eye. Its best view is through a binocular, as it spills outside a telescope’s eyepiece.

The cluster is a phase of the life of a star where astronomical theory predicts that stars are formed in bunches.  This cluster has about 200 stars; about a dozen appear through a binocular.

On the morning of September 14, look about 90 minutes before sunrise for brilliant Venus and the lunar crescent that is 12% illuminated.  They are 5.0° apart. The star cluster is 2.7° to the upper left of Venus; that’s about half the Venus – Moon gap.  The lunar crescent is 4.6° to the lower left of the cluster.  The star Delta Cancri (δ Cnc on the chart above) is 0.9° to the upper left of Venus.

Venus is slightly closer to the Beehive on the morning of September 13 and the moon is above the scene.  See the detailed notes below for more specific directions.

Photographers can catch the scene with a camera that has time exposure settings and a tripod mount or another means of holding a steady camera. Exposures from 1 to 5 seconds yield satisfactory results.  Exposures that are longer reveal Earthshine on the moon, sunlight reflected from Earth’s clouds, continents, and oceans that gently illuminate the nighttime moonscape.

The detailed notes that follow provide more specifics:

  • September 13: Venus passes 2.3° to the lower right of the Beehive cluster. The planet is also 1.5° to the upper right of (Delta Cancri (δ Cnc). One hour before sunrise, find the brilliant planet about 28° up in the east.  The waning crescent moon (25.3 days past the New Moon phase, 20% illuminated) is over 10° above Venus. The moon is also 6.1° to the lower right of Pollux. 
  • September 14: Venus is 5.0° to the right of the crescent moon (26.3d, 12%) and 0.9° to the lower right of δ Cnc. With a binocular observe that the Beehive cluster is 2.7° to the upper left of Venus and 4.6° to the upper right of the lunar crescent. One hour before sunrise, find Venus about 28° up in the east. 
The moon and Venus, September 15, 2020
2020, September 15: The crescent moon and Venus in the morning sky.
  • September 15: One hour before sunrise, Venus is nearly 28° up in the east.  It is 1.4° to the lower right of δ Cnc and 3.3° to the lower right of M44.  All three of these objects are nearly along a line that starts with the star cluster and ends with Venus.  The moon (27.2d, 6%) is about 15° up in the east.  It is 5.4° to the upper left of Regulus
The crescent moon, September 15, 2020
2020, September 15: The moon is in the east before sunrise. The thin crescent moon is 6% illuminated.

Here is a daily summary about the planets during September.

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