Skywatch Line for Monday August 30th and Tuesday August 31st, 2021

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 30th, and 31st, written by Joe Slomka.

The Sun sets at 7:33 PM; night falls at 9:14. Dawn begins at 4:38 AM and ends with the Sun rising at 6:19.

The Moon, in Taurus, reached Last Quarter on Monday; it rises at 11:46 PM in the Northeast, 29 arc-minutes large, 44% illuminated and sets at 3:35 PM Tuesday. The Moon doesn’t rise again until 12:27 AM Wednesday.

Western Virgo houses Venus and Mercury. Mercury sets first at 8:17 PM and appears 5 arc-seconds in size. Venus sets next at 8:55 PM, blazing with 4th magnitude, a large 15 arc-seconds and 73% lit. Both planets are very low and require an unobstructed view. Venus is 10° high while Mercury is only 3° above the horizon and 16° to Venus’ lower right.

Capricornus contains Saturn and Jupiter in the darkening southeast. Saturn appears first already up. By 8 PM, it is 15° high, shining with zero magnitude and is highest at 11 PM. Jupiter trails Saturn by 17° to Saturn’s left. The Gas Giant flashes with minus 2nd magnitude, a large 49 arc-seconds and highest at 12:14 AM. Both planets are in retro-grade, which means they both seem to temporarily back up westward.

Neptune, in Aquarius, is next, rising at 8:06 PM, glowing with 7th magnitude, a tiny 2 arc-seconds. Neptune is 10° high by 9 PM, 20° at 10 PM and highest at 1:53 AM. Neptune is nearing Opposition, which means almost ideal position for viewing. Uranus is last to rise, in Aries, at 10:05 PM, glimmering with 5th magnitude, 20° high at Midnight and is highest at 5:09 AM. By 1 AM, Uranus is 33° to the Moon’s upper right. At 5th magnitude, Uranus is visible through binoculars all night, but a sky chart is necessary to find it amid similar looking stars.

At 1 AM on Tuesday, Saturn, Jupiter, Neptune, Uranus and the Moon are arrayed in a straight line – the Ecliptic where the Sun, Moon and planets travel.

While looking at the Ecliptic, turn your binoculars to Mira, in Cetus. This star dims from third magnitude to 9th in a period of 333 days. The star reached maximum earlier in August and lies to the lower left of Uranus. Star charts help find it.

Ancient peoples saw the sky as the realm of the gods and told stories about their constellations. By midnight, all the constellations that make up the Andromeda story are visible. We previously mentioned Cassiopeia and Cepheus. Cassiopeia angered some gods and Ethiopia was subjected to severe calamities. An oracle told Cepheus that disasters would end if he chained Andromeda to a seaside rock to be eaten by the sea monster Cetus. Perseus was returning from a mission to kill the Medusa, a woman so hideous that her visage turned people to stone. One version of the myth has Perseus returning by his horse Pegasus. He hears Andromeda’s cry for help. The parents, nearby, promise her hand in marriage if he saves her. He kills Cetus and frees Andromeda. “W” shaped Cassiopeia and Cepheus, shaped like a stick drawing of a house, are visible overhead. Pegasus, the flying horse, is a Great Square high in the eastern sky, flying upside down; his neck begins at the lower right star of the square. Andromeda’s chains flow from the upper left star in the square and continues eastward. The famous Andromeda Galaxy lies above the upper chain and is visible to naked eyes in rural skies. Perseus appears to the east of Pegasus, resembling a stick drawing of a man with one long and one short leg. The brightest star in the short leg is Algol, the “Demon Star.” It represents the evil eye of the Medusa. Cetus lies beneath Pegasus and Pisces. It is a dim constellation low on the horizon for our latitude.

Skywatch Line for Friday, August 27, through Sunday, August 29, 2021

This is Dudley Observatory’s Skywatch Line for Friday, August 27, through Sunday, August 29, written by Sam Salem.

On Friday, Sun rises at 6:15am and sets at 7:38pm; Moon sets at 11:28am and rises at 10:17pm. For the second time this month, the bright, waning gibbous Moon will pass close to Uranus. After the Moon has climbed high enough to become visible late on Friday evening, look for the magnitude 5.8 Uranus sitting several finger widths to its upper left, close enough for them to share the view in binoculars. The blue-green dot of Uranus can be seen in binoculars. Note Uranus’ location between the stars of constellations of Aries and Cetus and hunt for it on a night when the bright Moon has moved away.

Venus, at magnitude –3.9, shines pure white in the west-southwest during twilight. It sets around twilight’s end. Jupiter, at magnitude -2.9, and Saturn, at magnitude +0.2, shine in the southeast in late twilight and after dark. They’re in constellation of Capricornus. Jupiter starts the night lowest. Saturn glows about two fists to Jupiter’s upper right. The pair levels out around 11 p.m. By then they’re about at their highest in the south.

Whenever bright Vega crosses nearest your zenith, as it does right after dark now, you know that the Sagittarius Teapot is at its highest due south. Two hours later when Deneb crosses closest to the zenith, it’s the turn of little constellation of Delphinus and boat-shaped constellation of Capricornus down below it to stand at their highest due south. After dark, the Milky Way runs from Sagittarius in the south, up and a bit left across Aquila and through the big Summer Triangle high overhead, and on down through Cassiopeia to Perseus low in the north-northeast.

These next few days, before daybreak, let the waning crescent Moon serve as your guide to the Winter Circle. The Moon passes through Winter Circle the next few days. Although it’s summer in the Northern Hemisphere, a major sign of winter now looms large in the predawn sky. Let the waning crescent Moon guide your eye to the Winter Circle in late August and early September. The Winter Circle, or the Winter Hexagon, is an asterism, a star pattern that is not a recognized constellation. This humongous star formation consists of six 1st-magnitude stars in six different constellations: Capella of the constellation Auriga the charioteer, Pollux of the constellation Gemini the Twins, Procyon of the constellation Canis Minor the Smaller Dog, Sirius of the constellation Canis Major the Big Dog, Rigel of the constellation Orion the Hunter, and Aldebaran in the constellation Taurus the Bull. The Winter Circle dwarfs the Mighty Orion the Hunter, which only makes up the lower right portion of the Winter Circle. If you are acquainted with Orion, this constellation presents a great jumping off place for circumnavigating this brilliant circle of stars. These stars are so bright that they’re even visible in the morning twilight. In late August and early September, the Winter Circle returns to the morning sky. But we still won’t see the Winter Circle in the evening sky for months to come.

Skywatch Line for Wednesday, August 25, and Thursday, August 26, 2021

This is Dudley Observatory’s Skywatch Line for Wednesday, August 25, and Thursday, August 26, written by Alan French.

A waning gibbous Moon, 86-percent illuminated, rises at 9:33 P.M. Wednesday. Moonrise on Thursday is at 9:55 P.M. and the visible face of the Moon will be 79-percent in sunlight. The Moon will reach last quarter early Sunday morning.

Venus continues to dominate the western sky as darkness falls. The Sun sets at 7:42 P.M. As the Sun sinks below the horizon and the western sky darkens, look for brilliant Venus toward the west southwest. At 8:11, the end of civil twilight, Venus, shining at magnitude -3.9, will be 9.5-degrees above the horizon. By 8:47, the end of nautical twilight, Venus will only be 3-degrees above the horizon.

When the sky is still bright with evening twilight, Venus may be hard to spot at first, but you might be surprised how bright and obvious it is once you see it. Your eye has a very narrow angle of high visual acuity, so you have to be looking almost right at Venus to detect it when the sky is bright. When the sky background is darker, detection is easier over a wider area of your visual field.

There are three stages of morning and evening twilight, civil twilight, nautical twilight, and astronomical twilight. Although the Sun is below the horizon and out of direct sight, all stages feature some brightening of the sky above the Sun.

The traditional, but imprecise, descriptions of civil and nautical twilight are simple. During civil twilight the Sun has set but normal activities can continue unimpeded by the reduced light. During nautical twilight it’s too dark for normal activities, but the horizon, the dividing line between the ocean horizon and sky, is visible. Nautical twilight ends when this demarcation is no longer visible.

There are more precise definitions. For the setting Sun, civil twilight begins when the Sun vanishes below the horizon. It ends when the center of the Sun is 6-degrees below the horizon, which is also the start of nautical twilight. Nautical twilight ends when the Sun’s center reaches 12-degrees below the horizon, which also signals the start of astronomical twilight. Astronomical twilight ends when the Sun is 18-degrees below the horizon, and the sky is completely dark

In the morning the process is reversed. Astronomical twilight begins when the Sun is 18-degrees below the horizon, and ends at the start of nautical twilight, when the Sun reaches 12-degrees below the horizon. Nautical twilight ends and civil twilight begins with the Sun 6-degrees below the horizon and ends with sunrise.

Because few of us live under truly dark skies, free of light pollution, the subtle glow of astronomical twilight may never be noticed.

Skywatch Line for Monday August 23rd and Tuesday August 24th, 2021

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 23rd, and 24th, written by Joe Slomka.

The Sun sets at 7:44 PM; night falls at 9:28. Dawn begins at 4:28 AM and ends with the Sun rising at 6:12.

Monday’s Moon, one day after “Full”, rises at 8:49 PM in Aquarius, is 97% illuminated and 31 arc-minutes in size; it sets at 8:16 AM, Tuesday. Tuesday’s Moon, in Pisces, rises at 9:21 PM, 93% lit, slightly smaller and sets at 9:21 AM on Wednesday.

Inner planets Mercury and Venus, brighten the low western evening. Mars is no longer visible. Elusive Mercury, in Leo, sets first at 8:26 PM, shining with minus zero magnitude and appearing 5 arc-seconds in size. Setting at 9:07 PM, Venus, in Virgo, lies 18° to Mercury’s upper right, blazes with minus 4th magnitude, and a larger 14 arc-seconds.

Meanwhile, giant planets Saturn and Jupiter are risen in the Southeast and share Capricornus. Saturn rises first at 6:44 PM, shines with zero magnitude, 18 arc-seconds, is highest at 11:29 PM and sets at 4:18 AM; it is 20° high at 9 PM and 25° at 10 PM. Jupiter rises at 7:34 PM, glimmers with minus 2nd magnitude, a large 49 arc-seconds, highest at 12:45 AM and sets at 4:52 AM; it is 14° high at 9 PM and 23° at 10 PM.

Neptune, in Aquarius, rises at 8:34 PM, glows with 7th magnitude, a tiny 2 arc-seconds, and highest at 2:21 AM. On Monday night, Neptune appears 18° above the Moon; Tuesday finds the Moon just rising with Neptune 12° to the upper right. Uranus still brings up the rear, rising in Aries at 10:33 PM, shimmering with fifth magnitude, a larger 3 arc-seconds, 15° high at Midnight. Both set during daytime.

The constellation Perseus is well up after Midnight. At 11:08 PM on Tuesday, the star Algol (also known as Beta Persei) dims. Algol, the “Demon Star,” varies its light every 2 days, 20 hours and 49 minutes. It fades from second magnitude to third – easily seen by the naked eye. The entire cycle takes about nine hours. Two hundred forty years ago, John Goodricke theorized that a dimmer star was partially eclipsing a brighter star. In 1889, the new technique of spectroscopy verified his theory. The main star is one hundred times the Sun’s luminosity. The eclipsing star is actually slightly brighter than our Sun. There is a third star that orbits the system once every 1.8 years, but plays little part in the occultation. The system is about 96 light years away and the most easily studied “eclipsing binary.” Astronomy magazines and websites provide timetables of its eclipses.

Skywatch Line for Friday, August 20, through Sunday, August 22, 2021

This is Dudley Observatory’s Skywatch Line for Friday, August 20, through Sunday, August 22, written by Sam Salem.

On Friday, Sun rises at 6:07am and sets at 7:49pm; Moon sets at 3:30am and rises at 7:16pm.

This weekend, enjoy the dusk-till-dawn light of the Moon. On Friday evening after sunset, look towards the southeast for the bright waxing gibbous Moon shining several finger widths below Saturn, with much brighter Jupiter positioned off to their left. As they cross the sky during the night the diurnal rotation of the sky will lift the Moon to Saturn’s left. They’ll set together in the west-southwest before dawn.

On Saturday, the gibbous Moon will hop east to sit below Jupiter and Saturn in the southeastern sky after dusk. The Moon will be somewhat closer to brighter Jupiter than Saturn, and just close enough for them to fit together in binoculars after midnight because the Moon’s eastward orbital motion will draw it farther from the planet. By the time the Moon drops below the west-southwestern horizon as the Sun is rising, it will have shifted to Jupiter’s left.

Full Moon occurs on Sunday, at 8:02am. Full Moon shines among or near the stars of Aquarius or Capricornus. This August full Moon is a seasonal Blue Moon. It’s the 3rd of four full moons in one season. For the Northern Hemisphere, this weekend’s full Moon counts as a summer Blue Moon. August full Moon is colloquially called the “Sturgeon Moon,” “Red Moon,” “Green Corn Moon” and “Grain Moon.” Since the full phase will officially occur on Sunday morning in the Americas, the Moon will appear to be full on both Saturday night and Sunday night. Magnified views will reveal a thin strip of darkness along the Moon’s western and eastern limbs on Saturday and Sunday night, respectively.

The two brightest stars of summer are Vega, now overhead shortly after nightfall, and Arcturus, shining in the west. Draw a line down from Vega to Arcturus. A third of the way down, the line crosses the dim Keystone of Hercules. Two thirds of the way down the line crosses the dim semicircle of Corona Borealis with its one modestly bright star, Alphecca or Gemma. Vega and the Keystone’s star closest to it form an equilateral triangle with Eltanin to their north. Eltanin is the brightest star of Draco’s quadrilateral head. He’s eyeing Vega.

As summer progresses and Arcturus moves down the western sky, the kite figure of Boötes that sprouts up from Arcturus tilts to the right. The kite is narrow, slightly bent with its top leaning right, and about two fists at arm’s length. Arcturus is its bottom point where the stubby tail is tied on. The Big Dipper now slants at about the same height in the northwest, to the Kite’s right.

Skywatch Line for Wednesday, August 18, and Thursday, August 19, 2021

This is Dudley Observatory’s Skywatch Line for Wednesday, August 18, and Thursday, August 19, written by Alan French.

A waxing gibbous Moon now brightens the evening sky. On Wednesday night an 85% illuminated Moon will be low in the south southeast at 9:00 P.M. Thursday night it will be closer to full, appearing 92% in sunlight. The Moon will reach full next Sunday morning.

On Thursday night at 9:00 P.M. the bright Moon, Saturn, and bright Jupiter will be low toward the southeast, with fainter, yellowish Saturn between the Moon and Jupiter.

Any telescope magnifying 50 or 60 times easily shows Saturn’s lovely rings. We always get our best view of the planets when they are high in the sky, and they appear highest when they are due south in our skies. Saturn will transit – pass due south – at 11:47 P.M., when it will be 28-degrees above the horizon.

Saturn’s largest Moon, Titan, is an easy sight through any telescope. On Wednesday night look for a star just below (south) of Saturn. On Thursday night, Titan will be to Saturn’s lower left (southeast).

Spotting scopes, designed for birding and nature study, give a magnified view matching the orientation you see by eye. Many astronomical telescopes provide an inverted or reversed view, or both, so the view may not match our description.

Skywatch Line for Monday August 16th and Tuesday August 17th,

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 16th, and 17th, written by Joe Slomka.

The Sun sets at 7:55 PM; night falls at 9:43. Dawn begins at 4:15 AM and ends with the Sun rising at 6:03.
The Moon rises in the constellation Ophiuchus on both nights. Monday it rises at 3:14 PM, 63% illuminated, 32 arc-minutes in size and sets at 12:32 AM, Tuesday. Tuesday’s Moon rises at 4:27 PM, slightly larger, 73% lit and sets at 1:22 AM, Wednesday.

Venus is the only planet visible in the evening western sky. In Virgo, it blazes with minus 4th magnitude and appears sized about 3 arc-seconds and sets at 9:18 PM. Mars is so low on the horizon that it is, in effect, not visible.

While Venus is setting, the Moon, Saturn and Mercury are rising in the southeast. In Capricornus, Saturn rises at 7:13 PM, shining with zero magnitude, 18 arc-seconds wide and is highest at Midnight. Jupiter, in Aquarius, follows 18 degrees to Saturn’s lower left, rising at 8:04 PM, sparkling with minus 2nd magnitude, a large 49 arc-seconds and highest at 1:16 AM. Jupiter reaches Opposition on Thursday, which means that it is at prime position for observation for the rest of the month. Neptune, also in Aquarius, is next, rising at 9:02 PM, 2 arc-seconds small, glowing with 7th magnitude, and highest at 2:49 AM. Uranus is last, in Aries, shimmering with 5th magnitude, and sized 3 arc-seconds. All four planets set either at or after sunrise.

By nightfall, Capricornus, Aquarius, Pisces and Cetus dominate the southern sky. All are water-based. Capricornus is a unique constellation: The Sea-Goat. The creature has the head of a goat, but the body of a fish. This part of the Zodiac is truly ancient; the Sumerians identified it as early as 1600 BC. A royal seal, from the town of Ur, is on display in the Boston Museum; the seal bears the image of Capricornus, just as it is pictured today. Boundary markers of Mesopotamian kings also depict Capricornus as we do. The source of this animal is a mystery. A people far removed from any large body of water invented it. The Goat-Fish was associated with the god Ea – the master of creation and the god of the underground seas, including fresh water springs. Ea resembles the Roman god Neptune. In 1846, the astronomer Galle discovered the planet Neptune in Capricornus.

Skywatch Line for Friday, August 13, through Sunday, August 15, 2021

This is Dudley Observatory’s Skywatch Line for Friday, August 13, through Sunday, August 15, written by Sam Salem.

On Friday, Sun rises at 6:00am and sets at 8:00pm; Moon rises at 11:29am and sets at 10:51pm. First quarter Moon occurs on Sunday, at 11:19 a.m. At first quarter, the Moon rises around mid-day and sets around midnight, so it is visible in the afternoon daytime sky. The evenings surrounding first quarter are the best ones for seeing the lunar terrain when it is dramatically lit by low-angled sunlight, especially along the terminator, the pole-to-pole boundary between the lit and dark hemispheres.

On Friday, as the stars come out, look for Spica, the brightest star in the constellation Virgo the Maiden, lower right of the Moon. They’re less than a fist at arm’s length apart. High to their upper right shines Arcturus, the brightest star in the constellation Boötes the herdsman.

As darkness falls on Sunday, the first quarter half-illuminated Moon will be close to the star Antares on the sky’s dome. Antares, the brightest star in the constellation Scorpius the Scorpion, represents the Scorpion’s beating heart. This red gem of a star is truly enormous, with a radius more than 3 astronomical units. If Antares were suddenly substituted for our Sun, the surface of the star would extend well past the orbit of Mars.

Venus, at magnitude –3.9, shines due west during twilight. It sets around twilight’s end. Jupiter, at magnitude -2.9, and Saturn, at magnitude +0.2, shine in the southeast in late twilight and after dark. They shine in or near the constellation Capricornus. Jupiter starts the night lowest. Saturn glows yellowly, about two fists at arm’s length to Jupiter’s upper right. The pair levels out around midnight. By then they’re nearly at their highest in the south, at their telescopic best.

The brightest star high in the southeast these evenings is Altair, the brightest star in the constellation of Aquila. Little orange Tarazed sits above it by a finger-width at arm’s length. Tarazed, or gamma Aquilae, is a star in the constellation of Aquila. A little more than a fist-width to Altair’s left is delicate constellation Delphinus, the Dolphin, leaping left. Above Altair, slightly less far, is smaller, fainter constellation Sagitta, the Arrow. It too is pointing leftward.

16 Psyche is one of the most intriguing targets in the main asteroid belt that orbits the Sun between the orbits of Mars and Jupiter. 16 Psyche is a giant metal asteroid, about three times farther away from the Sun than is the Earth. Its average diameter is about 140 miles, or about one-sixteenth the diameter of Earth’s Moon. Unlike most other asteroids that are rocky or icy bodies, scientists think the M-type (metallic) asteroid 16 Psyche is comprised mostly of metallic iron and nickel, similar to Earth’s core. Scientists wonder whether Psyche could be an exposed core of an early planet that lost its rocky outer layers due to several violent collisions billions of years ago. This asteroid is now the primary target of NASA’s Psyche mission. Targeted to launch in August of 2022, the Psyche spacecraft would arrive at the asteroid in early 2026. One of the mission’s goals is to determine whether Psyche is indeed the core of a planet-sized object. The Psyche mission will be the first mission to investigate a world of metal rather than of rock and ice. This offers a unique window into the violent history of collisions and accretion that created terrestrial planets.

Skywatch Line for Wednesday, August 11, and Thursday, August 12, 2021

This is Dudley Observatory’s Skywatch Line for Wednesday, August 11, and Thursday, August 12, written by Alan French.

The Moon was new last Sunday and is now in the early evening sky. Wednesday night a slender crescent Moon, 13% illuminated, will be a lovely sight near bright Venus. Look for the pair low in the west at 8:45 P.M. The Moon will be 13-degrees above the western horizon with bright Venus to its lower right, 8-degrees away.

As the Sun sinks farther below the horizon and the western sky darkens it will be easier to see that the entire Moon is visible. The bright portion is in sunlight, but it’s nighttime in the darker, fainter majority of the visible half of the Moon. From there a brilliant, nearly full Earth, would be visible in the Moon’s sky. It is this light – earthshine – that illuminates the darker portion of the Moon. As the Moon moves toward full, our Earth, as seen from the Moon, moves toward new, so its brightness, and earthshine, decreases.

Venus sets at 9:30 P.M. and the Moon sinks below the horizon at 10:03 P.M.

On Thursday at 8:45 P.M. the Moon will be 22% in sunlight, toward the west southwest, and 17-degrees above the horizon. It will set at 10:27 P.M.

The early moonsets make these wonderful nights for the Perseid meteor shower. Perseids are visible from around July 17 through August 24, but begin and end modestly. This year they will be at their peak and best during the pre-dawn hours Thursday, but there are some indications the peak could extend into late Thursday evening and Friday morning – another opportunity to catch clear skies.

The Perseid meteor shower is caused by debris from Comet 109P/Swift-Tuttle, a comet that travels around the Sun every 133 years. Earth travels through the debris left along its orbit every summer, and we see the Perseid meteor shower as the particles shed by the comet, entering our atmosphere at 60km/sec, compress, heat, and ionize air molecules in our atmosphere. When the molecules return to their normal state, they emit light, producing the streak we see as a meteor. The Perseids tend to be fast and produce many bright “fireballs.”

When we look determines how many meteors we see. If you trace the meteors backwards across the sky, you’ll find that the trails all lead back toward a point in Perseus near the famous Double Cluster. This apparent point of origin for the meteors is called the radiant. By 10 P.M. the radiant is 20-degrees high in the northeast and some Perseids will be visible, but many, streaking downward from the radiant, will be hidden by the horizon. We’ll see more between 2:00 A.M. and 4:30 A.M., when the radiant is high and fewer meteors are hidden by our horizon.

We also see more meteors after midnight because we are then on the front side of the Earth as it travels through space. Keep in mind, since we set the clocks ahead when we changed to Daylight Saving Time, that midnight is now 1:00 A.M. on our clocks.

Light polluted skies will hide some of the fainter Perseids, so try to find dark skies for the best show. If dark skies are not accessible, watch for some bright fireballs. Under dark skies, near the shower’s peak, you might average a meteor about every minute, but how often they appear varies considerably. They can appear anywhere in the sky, so look high in the sky where you have the best, darkest view. If you have a great view of the entire sky, look high in the northeast.

Skywatch Line for Monday August 9th and Tuesday August 10th, 2021

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 9th, and 10th, written by Joe Slomka.

The Sun sets at 8:05 PM; night falls at 9:57. Dawn begins at 4:04 AM and ends with the Sun rising at 5:56.

The Moon occupies Leo on both nights. Monday’s Moon rose at 6:45 AM and sets in the Northwest at 9:11 PM, 31 arc-minutes in size and 3% illuminated. Tuesday’s Moon rises at 7:55 AM, 7% lit, but still sized 31 arc-minutes, and sets at 9:37 PM. On the Tuesday, at Dusk, the Moon’s thin crescent will be faintly lit by “Earthshine” – sunlight reflected off the Earth and onto the Moon.

Venus and Mars also inhabit Leo. By Civil Twilight, Venus blazes with minus 4th magnitude, is about 13 arc-seconds, 80% lit, 9° high in the Northwest and sets at 9:29 PM. Mars, smaller and fainter, sets at 8:54 PM. Note that the Moon, Mars and Venus are very close and low on the western horizon and difficult to observe.
While Venus sets, Saturn and Jupiter are already up in the East. Saturn, in Capricornus, rises first at 7:47 PM, shines with zero magnitude, a moderate 18 arc-seconds and is highest at 12:32 AM: by 10 PM it is 20° high and 25° by 11 PM. Jupiter follows by rising in Aquarius at 8:34 PM, glows with minus 2nd magnitude, a large 49 arc-seconds and is highest at 1:47 AM; by 10 PM Jupiter is 14° high and 22° at 11 PM. Jupiter is visible all month. Late night telescopic astronomers can, at 1:27 AM Wednesday, witness the Moon Io casting its shadow on the planet’s face, followed by Io itself at 1:40; both exit Jupiter by 3:58 AM.

Neptune shares Aquarius with Jupiter, rising at 9:29 PM. It glows with 7th magnitude, and appears a small 2 arc-seconds. It is found about 24° to Jupiter’s lower left; by Midnight, it appears 16° high and is highest at 3:17 AM. Uranus, in Aries, rises last at 11:28 PM, glows with 5th magnitude and 3 arc-seconds. By 1 AM, it is 16° high. All four planets set at or after sunrise.

Thirty-four years ago, at Chile’s Las Campanas Observatory, Ian Shelton was testing a repaired telescope by photographing the Large Magellanic Cloud, a satellite galaxy to our own. After he developed the picture, he discovered a very bright star; walking outside, he sighted it visually. He spotted the first naked-eye supernova since 1885. Word raced through the astronomy community. Every telescope in the southern hemisphere was turned to the “new star”.

Supernovae are common, but are usually located in dim, distant galaxies. This one was next door, in astronomical distances. It could be easily studied and its makeup determined. Supernovae are important. The violent explosion creates elements heavier than helium. The atoms that make our bodies and everything in the Solar System were manufactured in the hellish temperatures and pressures of a supernova. As a result, we are all made of “star stuff.” While the remnant of this supernova is too far south for us to observe; the Crab Nebula, another supernova vestige in Taurus, is visible at 3 AM in amateur telescopes tonight.