Tag: Mercury

2018: December 13: Morning Star Venus and Mercury

Bright Morning Star Venus and Mercury shine during twilight this morning in the southeastern sky.  The planet Venus is at its earliest rising time this morning for this appearance, rising shortly before 3:30 a.m. CST.  Mercury is displaying a very favorable morning appearance, although it nearly always appears during twilight.

More about Venus and Mercury

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2018, December 9: Morning Star Venus and Mercury

Brilliant Venus shines in the southeast during twilight this morning. Mercury, low in the sky, joins this brighter inner planet. (Look for Mercury with binoculars to first locate it. Zoom in on the image to see the planet.) During the next several mornings, Mercury is brighter and higher in the sky. Jupiter joins the view later in the month.

For more about Venus, and Mercury and Jupiter’s morning dance, see the following articles:

2018: December’s Morning Planet Dance

Three bright planets appear low in the southeast sky during late December.  Watch their movement during the five days highlighted to see them move in a celestial dance against the starry background, especially with Mercury passing Jupiter. Both planets are among fourth and fifth magnitude stars in southern Ophiuchus.  Mercury reaches greatest elongation (21°) on December 15, rising nearly 110 minutes before sunrise.  It stands about 20° above the horizon at sunrise. After its greatest elongation, Mercury rises about 2 minutes later each morning.  While the planets are moving eastward compared to the stars, Mercury appears lower each morning when viewed at the same time, as it heads back into bright twilight toward its solar conjunction.   This morning elongation of Mercury bookends the year, nearly matching rising intervals during its apparition in January.  Mercury moves fastest.  Watch it as it moves past Psi Ophiuchi and onward toward Jupiter for a conjunction on December 21.  Venus, above the Claws of the Scorpion (Zubenelgenubi and Zubeneschamali), rises about 230 minutes before sunrise.  It moves closer to the Southern Claw during the mornings described below. A few weeks ago, Venus was at its phase of greatest brilliancy and greatest illuminated extent.  It appears about 25° above Jupiter and Mercury.   In comparison, Jupiter, about rising 90 minutes before sunrise, creeps against the sidereal scene. It is near Omega Ophiuchi.  Use binoculars to track the motion of the planets against the positions of the stars and to initially locate Antares which is very low in the sky.  The motion of Venus and Jupiter are described in detail in accompanying articles. The following describes the mornings at 45 minutes before sunrise:

December 19:  Brilliant Venus (m = −4.7) is 28° up in the southeast, 4.3° above Zubenelgenubi (α Lib, m = 2.8).  Bright Jupiter (m = −1.8) is 27° to the lower left of Venus.  Jupiter is 0.8° to upper right of Omega Ophiuchi (ω Oph, m = 4.4) and 5.3° to the upper left of Antares (α Sco, m = 1.0), although the star is only 3° in altitude.  Use binoculars to find it.  Mercury (m = −0.5) is 2.5° to the upper right of Jupiter and 1° to the upper right of Psi Ophiuchi (ψ Oph, m = 4.5).

December 20: This morning Jupiter is 1.6° below Mercury and 0.6° to the upper right of Omega Ophiuchi. Mercury is 0.6° to the lower left of Psi Ophiuchi.

December 21: Mercury, Jupiter and Antares are nearly in a line, spanning 6.1°; the Jupiter-to-Antares gap is 5.2°.  Jupiter is 0.9° to the lower right of Mercury, their closest separation, and 0.4° to the upper left of Omega Ophiuchi.

December 22: Jupiter is 1.2° to the right of Mercury (m = −0.4) and 0.2° to the upper left of Omega Ophiuchi.

December 23: Jupiter is 2° to the upper right of Mercury, which has an altitude of 5°.  The giant planet is 0.22° to the upper left of Omega Ophiuchi.  It passes 5.2° to the upper left of Antares and Mercury passes 6.1° to the upper left of the star.  Venus is nearly 25° to the upper right of Jupiter and 2.9° to the upper left of Zubenelgenubi.

Jupiter-Antares conjunctions become more difficult to see at the time of their next two conjunctions.  On December 4, 2030, Jupiter is only 6.5° west of the sun when it passes 5.1° from Antares.  At the November 23, 2042, conjunction, Jupiter is 8.8° east of the sun, setting 30 minutes after the sun, and passes 5.1° north of Antares. Mercury passes between them on November 20.  The November 8, 2054, conjunction occurs when Jupiter sets 75 minutes after the sun.  It is 24° east of the sun and 5.1° above Antares.  The next conjunction that has the pair perfectly-placed in the evening sky is July 13, 2090, when they are on the meridian at 10:00 p.m. CDT, Jupiter is 5.2° north of Antares.

Back to the current apparition of Jupiter:  After the Jupiter-Mercury activity, Venus moves between the Scorpion’s claws, heading for a widely-spaced conjunction with the giant planet in January.  This is followed by a conjunction with Saturn in February.  More details are in the accompanying articles; look for a focused article about the Venus conjunctions in the Winter issue.

Related Articles:

Venus in the Morning Sky, 2018-2019

Figure 1:  Venus shines in the morning sky with a crescent moon on September 17, 2017

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Photo Gallery

Venus as a Morning Star, 2018-2019

Venus returns to the morning sky in late 2018 and shines from the eastern sky until the middle of summer 2019.  The photo above (Figure 1) shows Venus on September 17, 2017, during the last morning appearance.  During  this appearance Venus has conjunctions with Jupiter and Saturn, and a close approach to Mercury.  Venus rises very rapidly in the morning sky after its inferior conjunction on October 26, 2018.  It seems to be chasing Spica into the sky.  By mid-December, Venus rises nearly four hours before sunrise, then begins to slide back toward the sun, taking nearly eight months to reach superior conjunction.

Bookmark this page to return to it follow the progress of Venus in the morning sky,

For readers wanting a detailed and more technical description of the appearance, click here.

Figure 2:  Venus at Inferior Conjunction: October 26, 2018

The morning appearance begins on October 26, 2018, when Venus moves between the earth and sun (inferior conjunction) (Figure 2). It is typically not visible at these times, but Venus is not lined up with the earth and sun. It passes below imaginary line between the earth and sun. Venus might be visible in the clear sky. Around noon, stand under an overhang that blocks the sun. Binoculars or a small telescope might be needed to initially locate it. It is very important not to point any optical instrument at the sun. The light collecting properties of the binoculars or a telescope can damage the device or cause irreparable damage to eyes if you are looking through them. With optical help from a telescope, Venus displays a very thin crescent.

Figure 3:  The rising times of stars and planets compared to sunrise.  The rising of Venus compared to sunrise
is displayed on the green line.  The moon’s rising is shown by the circles.

Venus then quickly moves into the morning sky the chart above (Figure 3) shows the rising time interval of Venus compared to sunrise; the rising time intervals for stars and other planets are shown as well. The circles show the rising time intervals for the moon.  The setting times for Jupiter and Saturn are included.  This occurs in the western sky.  When these planets set at sunrise, they are at opposition.

When the rising line of Venus crosses the rising line of another star or planet they rise at the same time. They are closest within a day or so of this intersection. When a moon circle appears near the rising line, the moon appears near Venus within a day or so.

The three phases of twilight: Civil Twilight, when the sun is 6° below the horizon; Nautical Twilight, sun is 12° below the horizon; and Astronomical Twilight, sun is 18° below the horizon at this time; the sky is as dark as it gets naturally.

This chart was composed from data by the US naval observatory for Chicago, Illinois.

Note that Venus appears seemingly suddenly in the morning sky. It appears to be chasing the star Spica. After Venus reaches its greatest brilliance and greatest elongation, it begins a slow fade into the sun’s glare. On the way it passes Jupiter, and Antares, and Saturn, along with other sign posts.

Venus and Spica, November 2018

Venus seems to be chasing Spica into the sky.  These charts show the pair about 30 minutes before sunrise.

Figure 4:  November 4, 2018, Venus is
4.4° below Spica.

  • November 4 (Figure 4): Only nine days after its conjunction, Venus rises an hour before sunrise this morning it is 4.4° below Spica with the waning crescent moon nearly 27° above Spica; notice the contrast of brightness. Venus is about 100 times brighter than Spica.

Update:  November 10, 2018


Figure 5:  Venus is closing the gap on Spica.

  • November 6 (Figure 5): Brilliant Venus is 3.6° below Spica with the waning crescent moon 9° to the left of the planet. Watch Venus close the gap on Spica during the next week.
  • November 9: Venus rises at the beginning of twilight, about 100 minutes before sunrise. After today, Venus rises before the beginning of twilight until March 14, 2019.
Figure 6: Venus closes about one degree of Spica in mid-November. There is no conjunction but this is the closest approach — a quasi conjunction
  • November 14: (Figure 6): The Spica chase ends when brilliant Venus closes to 1.2° of the star.  Venus does not pass Spica.  Because the separation is less than 5°, this is known as a “quasi-conjunction.”

Venus at Greatest Brightness

Figure 7:  This chart shows the location of Venus
during its 11-day stage of greatest brightness.

  • November 24: Now rising over 3 hours before the sun, brilliant Venus starts its stage of greatest brightness (Figure 7). For the next 11 days it displays its greatest visual intensity. It is important to note that this is not a singular event, but the duration of this greatest brightness occurs across several mornings.  More formally, Venus is near its greatest illuminated extent, defined as a geometrical configuration when Venus has an elongation of 40° – midway between inferior conjunction and greatest elongation.  This occurs December 1, when Venus’ illuminated portion covers more area of the sky than any other time during its apparition. (For a more technical explanation of greatest illuminated extent, see https://tinyurl.com/venus-greatest-illuminated.)  For our description, greatest brilliancy occurs during a 11-day period when Venus displays its greatest visual brightness.  Its brightness measured with light-sensitive equipment may slightly change, but our eyes cannot perceive that minute difference. 


Figure 8:  Look for Venus and Sirius about 2 hours before sunrise in late November.

  • November 29: As Venus is in the middle of its stage of greatest brightness, notice that it is about the same altitude (16°) as brightest star Sirius in the southwest, at about 100 minutes before sunrise. While it is not appropriate in formal astronomy to visually compare respective brightness of objects that are widely separated (101° in this case), notice that Venus is distinctly brighter (about 25 times) than Sirius – the brightest planet compared to the brightest star. Venus is now 5.3° to the lower left of Spica, about two weeks after their quasi-conjunction (Figure 8).

A Morning Planet Dance

 

Figure 9:  The morning planet dance of Venus, Jupiter, and Mercury in late December 2018.

  • December 19:  Today is the greatest time interval between Venus rising and sunrise. While the Venus rising time is still 3:23 a.m. CST (in Chicago), sunrise changed 4 minutes earlier during the past week.  The gap between sunrise and Venus rising now decreases, on average, about 1 minute each morning until Venus rises at Astronomical Twilight less than three months from this morning. Brilliant Venus is 28° up in the southeast, 4.3° above Zubenelgenubi (α Lib).  Bright Jupiter is 27° to the lower left of Venus.  Jupiter is 0.8° to upper right of Omega Ophiuchi (ω Oph) and 5.3° to the upper left of Antares, although the star is only 3° in altitude.  Use binoculars to find it.  Mercury is 2.5° to the upper right of Jupiter and 1° to the upper right of Psi Ophiuchi (ψ Oph). (See Figure 9)
  • December 20: This morning Jupiter is 1.6° below Mercury and 0.6° to the upper right of Omega Ophiuchi. Mercury is 0.6° to the lower left of Psi Ophiuchi.
  • December 21: Mercury, Jupiter and Antares are nearly in a line, spanning 6.1°; the Jupiter-to-Antares gap is 5.2°.  Jupiter is 0.9° to the lower right of Mercury, their closest separation, and 0.4° to the upper left of Omega Ophiuchi.
  • December 22: Jupiter is 1.2° to the right of Mercury (m = −0.4) and 0.2° to the upper left of Omega Ophiuchi.
  • December 23: Jupiter is 2° to the upper right of Mercury, which has an altitude of 5°.  The giant planet is 0.22° to the upper left of Omega Ophiuchi.  It passes 5.2° to the upper left of Antares and Mercury passes 6.1° to the upper left of the star.  Venus is nearly 25° to the upper right of Jupiter and 2.9° to the upper left of Zubenelgenubi.

Venus at Morning Greatest Elongation

Figure 10:  Venus at greatest elongation,
January 5, 2009

  • January 5, 2019: Venus reaches its greatest elongation from the sun (47.0°) (Figure 10). It is 13.6° above Antares. Jupiter is 14.2° to the lower left of Venus and 5.9° from Antares.  Venus and Spica are 35.3° apart. Through a telescope, Venus is nearly the same angular diameter as Mars when it was at its closest last summer (July 31).  Venus appears at its morning half phase.

Venus-Jupiter:  A Widely-Spaced Conjunction

Figure 11:  Venus, Jupiter, and Antares,
January 17, 2019.  Venus
approaches Jupiter

  • January 17: At 6:15 a.m. CST (60 minutes before sunrise), brilliant Venus is 20° up in the southeast (Figure 11). Venus passes 7.8° to the upper left of Antares.  Bright Jupiter is 5.1° to the lower left of Venus and 7.2° from Antares.  Venus is now two times farther from Earth than when we marked its greatest brilliancy, 49 days ago.  Through a telescope, Venus’ terminator is slightly, but distinctly, convex — indicating a morning gibbous phase.

Figure 12: A widely-spaced Venus-Jupiter conjunction.

  • January 22: Venus passes to the upper left of Jupiter this morning in a widely-spaced conjunction (2.4°) (Figure 12). Venus is 22° up in the southeast at 6:30 a.m. CST (40 minutes before sunrise). Venus passes Jupiter (1.1°) again on November 24, 2019, when they appear in the western evening sky on Venus’ next evening apparition. Venus and Jupiter resume their close (epoch) conjunctions with a difficult-to-see grouping on February 11, 2021 (0.4°). An easier-viewed epoch conjunction occurs on April 30, 2022 (0.5°).  Both of these close conjunctions occur in the morning sky.

Venus continues to move eastward against the starry background, away from Jupiter and toward Saturn.

Venus-Saturn Conjunction

Figure 13:  A Venus-Saturn conjunction,
February 18, 2019

  • February 18: At 6 a.m. CST (about 40 minutes before sunrise), Saturn is 13° up in the southeast. This morning is the Venus-Saturn conjunction (Figure 13).  Venus is 1.1° to the upper left of Saturn.  As with Jupiter (described on January 22), Venus has another conjunction with Saturn in the evening sky later this year.  On December 10, 2019, they appear 1.8° apart.  This is followed by a very close conjunction (0.4°) on February 6, 2021 in the morning sky close to sunrise.

Heading Into Twilight & A Close Approach to Mercury

  • March 14: Venus rises at Astronomical Twilight (93 minutes before sunrise) and for the rest of this apparition rises earlier during the phases of twilight. Through a telescope, Venus is growing in its morning gibbous phase. This morning, Jupiter is 90° west of the sun.  It is 52° to the upper right of Venus.  Saturn is 20.8° to Venus’ upper right.

Figure 14: A Venus-Mercury quasi-conjunction,
April 16, 2019

  • April 16: Venus and Mercury have a quasi-conjunction (4.3°) (Figure 14). (See the definition in the November 14 note.)  Mercury has a wide greatest elongation (27.7°), but the ecliptic is at a low angle for viewing. Even with its earliest rising on April 3, Mercury rose 8 minutes before Nautical Twilight, about 65 minutes before sunrise.  You’ll need binoculars to see it in the east-northeast sky.  This morning, Mercury rises 15 minutes after Nautical Twilight.

Figure 15:  A Venus-Mercury-Moon grouping,
May 2, 2019

  • May 2: The waning crescent moon (27.1 d) is 4.3° to the lower right of Venus. Mercury is 8.5° to the lower left of Venus, just above the horizon (Figure 15).  The time interval between Astronomical Twilight and sunrise grows 24 minutes from this morning through mid-June.  While Venus is rising at the same time interval before sunrise for the next month, it appears in a brighter sky.  Note this on the rising chart (Figure 3).

A Bright Twilight Conjunction With Aldebaran

Figure 16:  Venus-Aldebaran,
June 17, 2019

  • June 17: Now rising less than hour before sunrise, Venus passes 4.7° to the upper left of Aldebaran (Figure 16). This will test your observing skills with a telescope. Venus is in a slow slide into the sun’s glare, rising, on average, about 1.7 minutes later each day.

Heading Toward Conjunction

 

Figure 17:  Venus and the moon, July 1, 2019

  • July 1: At 4:55 a.m. CDT (35 minutes before sunrise), a very thin crescent moon (28.0 d) stands 6.3° to the right of Venus (Figure 17). The planet is 3.6° off the east-northeast horizon, another challenge for your observing location and your observing skills.

July 21: Clearly rising in bright twilight, Venus rises farthest north, azimuth equals 57°, the same position the sun rose at the summer solstice. Tomorrow, Venus rises at Civil Twilight (sun’s altitude is −6°), about 30 minutes before sunrise.Figure 18:  Venus at Superior Conjunction,
August 14, 2019

  • August 14: Venus is at superior conjunction, 1:07 a.m. CDT (Figure 17).  This appearance of Venus ends.

 

Appearances with Moon

  • November 6, 2018 (8.9°)
  • December 3, 2018 (5.6°)
  • January 1, 2019 (5.4°)
  • January 31, 2019 (2°)
  • March 2, 2019 (4.3°)
  • April 1, 2019 (8.7°)
  • May 2, 2019 (4.3°)
  • June 1, 2019 (6°)
  • July 1, 2019 (6.3°)

2018: September 8: Mercury, Regulus and the Moon #astronomy #moon

September 8: Before sunrise, locate the thin waning crescent moon (28.0 d, 2%) 1.8° to the upper left of Regulus with Mercury 4.4° below the star. Mercury (m = −1.2) is only 4.5° up in the east-northeast 30 minutes before sunrise. You’ll need a clear horizon and binoculars to see the trio in bright twilight.

2018, September 6: Mercury and Regulus in the Morning Sky

September 6: In the predawn eastern sky, the waning crescent moon (26.0 d, 15%) is on a virtual line that connects the Gemini Twins, Castor (α Gem, m = 1.6) and Pollux (β Gem, m = 1.2). The moon is 9.2° from Pollux. Thirty minutes before sunrise, with binoculars, look in the east-northeast for Mercury (m = −1.1) 1.2° to the left of Regulus. Mercury is 6.5° up in the sky.

In the evening sky, Saturn’s retrograde ends. It is 5° to the upper right of Kaus Borealis (λ Sag, m = 2.8), the star at the top of the lid of the Teapot of Sagittarius, and 45° from Jupiter. Mars and Jupiter have the same visual brightness (m = −1.9). Because they have distinctly different colors, do they appear to be the same brightness to you? While they are over 70° apart, it is not appropriate in formal astronomy to compare respective objects’ brightness, but it is a fun activity. Look near the end of twilight because they have nearly the same altitude early in the evening.

2018, September 1: Mercury Approaches Regulus

 

September 1: Mercury (m = −9) is 10° up in the east-northeast, 30 minutes before sunrise.  It is approaching a conjunction with Regulus (α Leo, m = 1.3).  This morning Regulus is 7.8° below Mercury, and very difficult to locate, even with optical assistance and a perfect horizon.

In the evening sky, for most of the month, Venus (m = −4.7) and Spica (m = 1.0) set at nearly the same time, 85 minutes after sunset this evening.  As they separate, Venus moves farther south.  (Recall that the farther north an object the longer it stays in the sky.)  As they slide into twilight the largest time gap in their setting times is 15 minutes. Jupiter (m = −1.9) is 24° to the upper left of Venus. (If the Martian dust storms subside,) At 10 p.m. CDT, when Mars is near the meridian about 22° up, it may provide excellent telescopic views. Mars moved into the boundaries and in front of the sidereal backdrop of Capricornus.