2022, June 13: Mercury Becoming Morning Planet, Evening Antares, Moon

June 13, 2022: Mercury continues its slow entrance into the morning sky to join the predawn planet parade.  After sundown, the bright moon is near Antares.

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by Jeffrey L. Hunt

Chicago, Illinois:  Sunrise, 5:15 a.m. CDT; Sunset, 8:27 p.m. CDT.  Check local sources for sunrise and sunset times for your location.

Morning Sky

SUMMARY OF PLANETS IN 2022 MORNING SKY

The morning planet parade is slowly adding Mercury.  The planet is emerging from bright twilight.  The speedy planet’s appearance makes five bright planets in the sky simultaneously.  The unusual tidbit about this appearance is that the five planets are visible in order from the sun – Mercury, Venus, Mars, Jupiter, and Saturn.

In addition, the bright five are joined by the dimmer planets, Uranus, Neptune, and the classic ninth planet Pluto.  Currently, Venus is in the same binocular field as Uranus, although the dim aquamarine planet is in bright twilight.

The visibility of Neptune is possible with some “star hopping” or a computer-guided telescope.  To see Pluto, a larger telescope and a dark sky is needed.  Because the planet is a challenge to spot, observations are needed across multiple days to see it move against the distant starry background.  Find more about how to look for Neptune and Pluto in this article or listen to the June 6^th podcast.

For the four easily-found planets, start at the western edge of the parade. The Venus – to Saturn span is over 83°.  Rising over five hours before sunrise, Saturn, retrograding in eastern Capricornus near the star Deneb Algedi, is over 30° above the east-southeast horizon at one hour before sunrise. 

While looking for Saturn, look for the star Fomalhaut, nearly 15° above horizon and to the lower left of the Ringed Wonder.

Farther eastward, bright Jupiter and Mars, are about one-third of the way up in the east-southeast.  Slow-moving Jupiter is trailing behind Mars, as the Red Planet marches eastward after their recent conjunction.  Mars is noticeably dimmer than the Jovian Giant.

At this hour, brilliant Venus is nearly 8° above the east-northeast horizon.  Find a sky watching spot with a clear horizon.  Venus is quickly stepping eastward away from the slower-moving worlds in the solar system.

The Pleiades star cluster is 13.1° to the left of the Morning Star. Use a binocular to locate it

The star Capella is low in the north-northeast, appearing slightly higher in the sky than Venus. The star appears low in the north-northwest after sunset. This occurs for most regions in the continental US.  During the night, Capella sets and reappears in the north-northeast before sunrise.

Mercury is not visible at this hour. Fifteen minutes later, it is very low in the east-northeast, 11.4° to the lower left of Venus.  In this level of twilight, a binocular may be necessary to initially locate Venus, unless you’ve followed it since it was first spotted earlier during twilight.  The optical assist of a binocular is certainly needed for Mercury, Mars, and Saturn this morning.  The complete span from Mercury – Saturn is nearly 95°.

Evening Sky

The bright moon is about 10° up in the southeast as night falls, less than 12 hours before its Full moon phase. The moon’s brightness overwhelms the dimmer stars in the sky.  This evening, the star Antares is 8.1° to the upper right of the lunar orb.

Antares – meaning “the rival of Mars” – is displayed as the heart of the Scorpion on celestial artwork.  The constellation has not completely appeared above the horizon at this time.

The name appears to be derived from Mars’ nearly biennial appearance near the star.  They are about the same apparent brightness and nearly the same color, although Mars is a planet that shines from sunlight reflected from its iron-encrusted surface.

Antares is an unusual star, an equivalent to Betelgeuse in Orion, one of winter’s gems.  It is a red supergiant, shining from 600 light years away at a brightness of over 9,000 suns. 

Imagine two metal globes that are the same size at different temperatures, one hot enough to glow red, while the other shines with a blue-white color.  The blue globe is brighter than the red one.  To get the red globe to shine at the same brightness, it must be larger than the blue one.  Bright red stars are larger than bright blue ones. 

Any small, reddish star is dim and a challenge to see.  Interestingly, over 70% of the stars closest to our sun are dim, red stars, but they are not easily observed.

With Antares’ luminosity, it must be very large.  Estimations show that if the sun were replaced with Antares, the red star’s outer layers would extend beyond Mars and nearly halfway to Jupiter.  If it were empty, it could hold about 10 million stars the size of the sun.

Like Betelgeuse, Antares is thought to be near the end of its stellar life cycle.  After a star fuses the hydrogen at its core, it fuses other elements at higher temperatures, causing the star’s outer layers to expand, cool and redden. Eventually the star’s core cannot reach high enough temperatures to continue stellar fusion.  The star expands rapidly (explodes) and suddenly brightens – a supernova.  In the year 1054, a star went supernova that was visible during the daytime for over three weeks and at night for about two years, before it faded from eyesight.  Today, a cloud of gas continues to expand from the region of space described by Chinese astronomers.  This supernova remnant is commonly known as the Crab Nebula. Whether an Antares supernova and aftermath reaches such proportions is yet to be seen.

The moon reaches its Full (Strawberry) moon phase tomorrow morning at 6:52 a.m. CDT.

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