Category Archives: Skywatch Line

This is Dudley Observatory’s Skywatch Line for Friday, August 12, through Sunday, August 14, written by Sam Salem.

On Friday, Sun rises at 5:58am and sets at 8:01pm; Moon sets at 6:16am and rises at 8:56pm.

Perseid Meteor Shower will peak after midnight on Friday. The best time for seeing the most Perseids meteors will be the hours before dawn on Saturday morning when the shower’s radiant in Perseus will be highest in the northeastern sky. Perseid Meteor Shower runs between July 17 and August 26 every year. This is the most popular shower of the year, delivering as many as 100 meteors per hour at the peak. Perseid Meteor Shower is derived from debris dropped by Comet Swift-Tuttle. Many Perseids are extremely bright and leave persistent trails. This year, a nearly full Moon will shine all night long on the peak date, reducing the number of meteors we will see. To enjoy meteor showers, find a dark location with open sky and just look up.

Catch the waning crescent Moon between Saturn and Jupiter overnight on Friday and Saturday. You can spot the trio all night until dawn. While Saturn is up all night, Jupiter doesn’t rise until around 10 pm. They’ll be a glorious sight before dawn. On Sunday evening, the waning gibbous Moon will shine a palm’s width to the right of Jupiter, close enough to be viewed together in binoculars. Through the night, the diurnal rotation of the sky will shift the Moon below Jupiter. On Monday night, the Moon’s orbital motion will cause it to hop east to Jupiter’s lower left.

Towards the middle of August, Mars will join Jupiter and Saturn in the evening sky. If you have an unobstructed eastern horizon, you should be able to spot Mars peeking above the horizon within a few minutes after midnight. Watch for the bright Pleiades star cluster shining nearby. Mars will look its best in a telescope when it is highest in the southeastern sky before dawn.

On Sunday, Saturn will reach opposition among the stars of eastern Capricornus. At opposition, Earth is positioned between the planet and the Sun. Therefore, planets at opposition are visible all night long, rising at sunset and setting at sunrise. At opposition, Saturn will be at a distance of 823.3 million miles, or 73.7 light-minutes from Earth. It will shine at magnitude of 0.28, its brightest for this year. While planets at opposition always look their brightest, Saturn’s peak magnitude will be enhanced by the Seeliger effect, backscattered sunlight from its rings. Saturn’s rings will be tilting more edge-on to us every year until the spring of 2025. Opposition is also a fine time to view a handful of Saturn’s moons with a backyard telescope in a dark sky. Saturn will be highest in the sky around midnight.

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, August 10 and 11, written by Alan French.

The Sun rises at 5:56 A.M. and sets at 8:04 P.M. on Wednesday. On Thursday it rises at 5:57 and sets at 8:03. Thursday has almost 17 minutes less daylight than a week ago.

The Moon reaches full Thursday evening. On Wednesday the Moon, appearing 98% full, rises in the southeast at 7:44 P.M. It rises at 8:24 on Thursday in the east southeast and reaches full at 9:37 P.M., when it will appear just 10 degrees above the horizon toward the southeast. This full Moon is known as the Sturgeon Moon.

Thursday’s full Moon lies close to Saturn. At 10:00 P.M. Saturn will be, relative to the Moon, at about the 11 o’clock position, and lie only 5 degrees away.

We are approaching the peak of this year’s Perseid meteor shower, which occurs every August when the Earth passes through debris left by Comet Swift-Tuttle as it orbits the Sun. Under dark, moonless skies, the Perseids produce an average of about 1 meteor every minute at its peak, which occurs just before mid-month. The bright Moon, unfortunately, will render about half invisible, hidden by the bright sky, but it will still be a respectable shower. The Perseids also produce more fireballs, bright meteors out-shining the brightest stars, than any other meteor shower.

The peak for the shower for us is Friday night through Saturday morning, but the previous two nights, especially Thursday night into Friday morning, should also be good opportunities to see Perseids. Viewing opportunities here are often dependent on the weather, so latitude in when to watch is good and taking advantage of clear skies, even if before the peak, is wise.

Two factors make the early morning hours best for watching for Perseids. First, after midnight we are on the front side of Earth as it travels through space, so meteors are more plentiful. Because we set our clocks ahead an hour in the spring, midnight is 1 A.M. EDT.

Second, showers are more prolific when the radiant, the point in the sky the meteor trails point back toward, is high in the sky. The radiant for the Perseids is, of course, in the constellation Perseus, below the easily recognized “W” pattern of the constellation Cassiopeia. Although their paths trace back toward the radiant, Perseids can appear anywhere in the sky. When the radiant is well up in the sky fewer meteors are cut off by the horizon.

From Schenectady the radiant is 38 degrees above the northeastern horizon at 1 A.M. and 53 degrees high by 3 A.M. For best viewing find a spot with a good view of the sky, look high toward the northeast from a comfortable reclining lawn chair, dress warmly, and remember, with any meteor shower, patience is often rewarded.

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday, August 8th, and 9th, written by Joe Slomka.

Monday’s Sun sets at 8:00 PM; night falls at 9:59. Dawn breaks at 4:02 AM and ends with the Sun rising at 5:54.

Constellation Sagittarius houses the Moon on both nights. Monday, it rises in the southwest at 5:48 PM, appears 33 arc-minutes in size and 87% illuminated. Moon set is at 2:23 AM, Tuesday; Tuesday’s Moon rises at 6:52 PM, 33 arc-minutes and 94% lit. Wednesday’s Moonrise is at 3:35 AM, 12° high, 33 arc-minutes and 97% lit.

At Civil Twilight, 3 solar system members are easily visible. Mercury is not among them. Mercury, in Leo, glimmers with zero magnitude is only 3° above the western horizon in a very poor appearance, due to proximity to the Sun. Southeastern Saturn, inhabits Capricornus, shining with zero magnitude, a moderate 18 arc-seconds, is only 2° high after rising at 8:24 PM and highest at 1:25 AM. Minor Planet 4Vesta rises at 9:21 PM, 10° below Saturn, shining with 6th magnitude, a tiny half-arc-second, 99% lit and highest at 2:17 AM. Neptune is next, rising at 9:40 PM, glowing with 7th magnitude, a tiny 2 arc-seconds, highest at 3:31 AM and 37° high at Civil Dawn (5:23 AM).

Giant Jupiter, in Cetus, glimmers with minus 2nd magnitude, a large 46 arc-seconds, 99% lit, rises at 10:11 PM and is highest at 4:21 AM. Jupiter is the scene of two observable events. The first is a double shadow transit, which means that the Jovian satellites Ganymede and Io begin to cross the planet’s face, both as a satellite and its shadow; it begins at 9:30 PM on Monday and ends at 3:08 AM Tuesday. At the same time, the Great Red Spot (a giant storm) also is visible at 1:26 AM. Both events are telescopically visible.

Aries contains Uranus and Mars; last week, they were in conjunction, now 4° apart. Southeastern Uranus rises at 11:44 PM, shines with 6th magnitude, 3 arc-seconds and 58° high at Civil Dawn. Brilliant Mars follows at 12:05 AM, shimmering with zero magnitude, 8 arc-seconds, 84% lit and 55° high at Civil Dawn. Venus, 63° from Mars, brings up the rear, blazing with minus 3rd magnitude, 10 arc-seconds in size, rises at 4:14 AM and is 11° high at Civil Dawn.

Thirty-five years ago, at Chile’s Las Campanas Observatory, Ian Shelton tested a repaired telescope by photographing the Large Magellanic Cloud, a satellite galaxy to our own. The developed picture revealed a bright star; walking outside, he sighted it visually – 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 found in dim, distant galaxies. This one was next door, in astronomical distances. It was 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.

This is Dudley Observatory’s Skywatch Line for Friday, August 5, through Sunday, August 7, written by Sam Salem.

On Friday, Sun rises at 5:51am and sets at 8:11pm; Moon rises at 2:02pm. First-quarter Moon occurs at 7:07am on Friday. After dark the Moon shines in central of the constellation of Libra. Stars Delta Scorpii, and then brighter Antares are to Moon’s left. Spica is farther to its lower right, and Arcturus shines even farther to the Moon’s upper right.

The Moon is in a waxing gibbous phase on Saturday and Sunday, more than half lighted but less than full. The moon will be bright in our sky as evening falls. On those evenings you’ll find the bright Moon near reddish Antares, the Heart of Scorpius the Scorpion. A red-looking star that you can see with the unaided eye is either a red giant or a red supergiant star. Antares is a red supergiant. On Saturday after dusk, the waxing gibbous Moon will shine in western Scorpius, between Antares, and the up-down row of small white stars that form the scorpion’s claws, Jabbah or Nu Scorpii, Graffias or Acrab, Dschubba, Pi Scorpii and Rho Scorpii. Use a telescope to reveal that Nu Scorpii, Graffias and Dschubba are close-together double stars.

At first quarter, the Moon rises around mid-day and sets around midnight. 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 that separates the lit and dark hemispheres. On Sunday night, the terminator on the waxing gibbous Moon will fall just west of Sinus Iridum, the Bay of Rainbows. That semi-circular feature is a large impact crater that has been flooded by the same basalts that filled the much larger Mare Imbrium to its east, forming a rounded “handle” on the western edge of the mare. The “Golden Handle” effect is produced when low-angled sunlight brightens the prominent Montes Jura Mountain range surrounding Sinus Iridum on the north and west. Sinus Iridum is almost craterless but hosts a set of northeast-oriented wrinkle ridges that are revealed at this phase.

Mercury is very low and bright, about -0.5 magnitude, in the glow of sunset. Try locating Mercury, about 30 minutes after sunset, with binoculars just above the horizon a little to the right of due west.

Venus, magnitude –3.9 in Gemini, continues to rise just as dawn begins. As dawn brightens, look for it low in the east-northeast. It’s far below Capella.

Mars, magnitude +0.2 in Aries, rises around 1am and shines high in the east-southeast as dawn begins. It rises about four fists lower left of Jupiter. By dawn they’re high in the south, with Mars now directly left of Jupiter. Uranus, magnitude 5.7 in Aries, is in the background of Mars.

Jupiter rises due east around 11 pm, shining at a magnitude –2.7 at the Pisces-Cetus border. It’s highest in the south as dawn begins.

Saturn, magnitude +0.4 in western Capricornus, is very low in the east-southeast in late twilight. It is at its highest and best in the south around 1am. Saturn’s rings appear roughly as wide, end to end, as Jupiter’s disk.

Neptune, magnitude 7.9 at the Aquarius-Pisces border, is high in the south before the first light of dawn, west of Jupiter.

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 1st, and 2nd, written by Joe Slomka.

Monday’s Sun sets at 8:23 PM; night falls at 10:25. Tuesday, Dawn breaks at 3:52 AM and ends with the Sun rising at 5:48.

Virgo houses the Moon on both nights. Monday’s four-day-old Moon rises at 11:40 AM, appears 31 arc-minutes in size, 35% illuminated, 21° high at 9 PM and sets at 11:11 PM. Tuesday, it rises at 10:34 AM, 30 arc-minutes, 25% lit, 19° high at 9 PM and sets at 11:50 PM.

Variable star Algol, in Perseus, reaches maximum at 1:05 AM on Wednesday. Observers should begin about 2 hours before maximum.

The Moon is the main attraction for both evenings. However, the night sky is slowly filling with planets. Saturn rises at 8:53 PM, in southwestern Capricornus, sparkles with zero magnitude, 18 arc-seconds in size, 2° high at 9 PM and 16° high at 5:16 AM (Civil Dawn), Tuesday; Saturn’s rings span 43 arc-seconds and the rings appear 18 arc-seconds wide. Neptune rises next in Pisces at 10:07 PM, shines with 7th magnitude, 2 arc-seconds and 40° high at Civil Dawn. Giant Jupiter is third, rising in Cetus at 10:38 PM, glimmering with minus 2nd magnitude, 45 arc-seconds, highest at 4:49 AM, 4° high at 11 PM and 48° at Civil Dawn; Tuesday, its Great Red Spot (a giant storm) is telescopically visible at 12:40 AM.

Aries houses Uranus and Mars on both nights. Fifth magnitude Uranus rises at 12:15 AM, 3 arc-seconds and 54° high in the southwest. Mars rises next at 12:20 AM, glowing with zero magnitude, 8 arc-seconds in size and 52° high at Civil Dawn. Mars and Uranus are in conjunction, only 1° apart, a rare treat. Mars is 150 times brighter than Uranus, but Uranus’ green-blue atmosphere clashes with Martian rust-red soil. Venus, 60° to Mars’ left in Gemini, rises last at 4 AM, blazing with minus 4th magnitude, 10 arc-seconds, 85% lit and 52° high; Venus is another delight since it rises with the bright stars Castor and Pollux.

Monday’s International Space Station (ISS) rises in the northwest at 9:04 PM, highest at 9:10 in the southwest and sets into the southwestern Earth’s shadow at 9:13 PM.

This summer, the country is experiencing heat waves of epic proportions. Television forecasters used the phrase “Dog Days.” That expression harks back to antiquity. Although most people observe Canis Major, the Big Dog, in winter, it, and its brightest star, Sirius, rises just before sunrise. Ancient Mesopotamians, Egyptians, Greeks and Romans knew this. All named the constellation as a dog. The word “Sirius” comes from the Greek for “scorching.” Indeed, the star rises during the hottest time of the year for the Northern Hemisphere. These cultures considered the constellation bad news. Heat was reputed to cause people and animals to become feverish, mad or warlike. Myths say men turned into werewolves, while animals contracted rabies. Today, we see the star as brilliant white; however, some ancient astronomers saw it as “reddish.” When Sirius first rises, it is, of course, low on the horizon, and appears red, just like a newly risen Sun. Egyptians did find one bright spot during the Dog Days. The rising of Sirius also signaled the beginning of annual Nile floods. These floods not only irrigated farms but also deposited vital nutrients, fertilizing the soil.

This is Dudley Observatory’s Skywatch Line for Friday, July 29, through Sunday, July 31, written by Sam Salem.

On Friday, Sun rises at 5:44am and sets at 8:19pm; Moon rises at 6:14am and sets at 9:21pm. After sunset on Friday, use binoculars to look just above the west-northwestern horizon for the very slender crescent of the young Moon shining two finger widths to the upper right of the magnitude -0.74 planet Mercury. They’ll be close enough to share the view in binoculars.

The annual Southern Delta-Aquariids meteor shower will peak from dusk on Friday through dawn on Saturday. It is quite active for a week surrounding the peak. This shower, produced by debris dropped from periodic Comet 96P/Machholz, commonly generates 15-20 meteors per hour at the peak. It is best enjoyed from the southern tropics, where the shower’s radiant, in southern Aquarius, climbs higher in the sky. On Friday night, the number of meteors will appear while the radiant is highest in the sky, at around 3am. The young crescent Moon will have followed the Sundown, leaving the entire night dark for meteor-watchers.

On Friday, the eastward prograde motion of the planet Jupiter through the background stars near the border between Pisces and Cetus will slow to a stop. Subsequently, Jupiter will commence a westward retrograde loop that will last until the end of November. Around midnight in late July, Jupiter will be shining in the lower part of the eastern sky. The planet will remain visible as it climbs south until the dawn twilight hides it. Retrograde loops occur when Earth, on a faster orbit closer to the Sun, passes more distant planets on the inside track, making them appear to move backwards across the stars.

In the southeastern sky during the mornings, the eastward orbital motion of Mars will carry it towards Uranus from the right. On Sunday, Uranus will be positioned a thumb’s width to the upper left of Mars, close enough to share the eyepiece of a low magnification telescope and binoculars. At closest approach on August 2, Uranus will be located 1.5 degrees above Mars. try to view the pair between 3 and 4am, when they will sit almost halfway up a darkened sky. The elusive 7th planet from the Sun is dim, shining at magnitude 5.8. Some people can spot objects of magnitude 6 with their eye alone. But unless you have a very dark skies and great eyesight, you’ll need a pair of binoculars or a telescope to see Uranus. Uranus is a challenge to observe because it’s just one point of light floating against the background stars of similar brightness. But on Saturday and Sunday, Mars would guide you to Uranus’ location. Mars shines bright at magnitude 0.2 and has a reddish glow. Look high above the southeastern horizon to spot it, then use binoculars to focus on Uranus hiding in the dark depths nearby.

Uranus will be to the upper left of Mars. It’s the brightest point of light close to Mars.

Orion the Hunter is one of the sky’s most easy-to-spot constellations. In late July and early August, look eastward as darkness gives way to morning dawn. Orion always passes behind the Sun in Northern Hemisphere spring. By June, Orion is gone from our sky. At this time of year, Orion returns, ascending in the east before sunrise. The Hunter rises on his side, with his three Belt stars, Mintaka, Alnitak, and Alnilam, pointing upward. The names of the Belt stars are derived from Arabic. Mintaka means “the belt”. Alnitak means “the gridle”. Alnilam is derived from Arabic word, “al-nizam”, meaning “string of pearls”. Alnitak is surrounded by the bright emission nebula IC 434. Silhouetted against IC 434 is the famous dark horsehead Nebula, which lies just south of Alnitak.

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, July 27 and 28, written by Alan French.

The Sun rises at 5:42 A.M. and sets at 8:21 P.M. on Wednesday. On Thursday it rises at 5:43 and sets at 8:20. Thursday has 13 ½ minutes less daylight than a week ago.

The Moon is new early Thursday afternoon so these nights will be moonless and dark. Early risers Wednesday with a good view to the northeast have a chance to spot a very thin old Moon. At 4:45 A.M. on Wednesday bright Venus will be in the east northeast, 8 ½ degrees above the horizon. The slender crescent Moon, less than 2% in sunlight, will be to the lower left of Venus, just under 10 degrees away and 4 degrees above the horizon. (Remember that a fist held at arm’s length spans 10 degrees across the knuckles.)

There are nice passes of the ISS over our area on both nights. The passes will cross the northern skies and Wednesday night’s pass will be highest.

The International Space Station is visible because it is up in sunlight while we are down in the Earth’s shadow and darkness. The ISS is the brightest manmade object in Earth orbit because it is large and reflects a lot of sunlight. When high in the night sky it outshines all the stars. The times and path description are for Schenectady, but will be close enough for anyone in the surrounding region. Its brightness and motion, most obvious when high in the sky, makes it easy to spot among the stars.

On Wednesday evening the ISS will first be visible around 9:56 rising up from the northwestern horizon. By 9:58 it will be approaching the front of the Big Dipper’s bowl and will pass close to Dubhe, the top star in the front of the bowl. At 9:59 the ISS will be approaching the Little Dipper’s bowl and will pass just below it. At 10:00 it passes close to Deneb, the brightest star in Cygnus, the Swan. Just before 10:01 the ISS, headed toward the east southeastern horizon, will move into the Earth’s shadow and fade from view.

Thursday night’s pass will be similar but lower across the sky. The ISS will first appear in the northwest around 9:08 P.M. By 9:09 it will be passing between the end of the Big Dipper’s bowl and the horizon. It will pass below Polaris, the North Star, at 9:10:30 and continue toward the east. At 9:12 it will pass below Cygnus, the Swan and will vanish low in the east just after 9:14.

Having the ISS in the northern sky means that people somewhere north of us will see it pass directly overhead. For Wednesday night’s pass, folks on New York’s border with Canada will see it overhead. Thursday’s pass is lower for us, and you’d have to be a little north of Quebec to see it overhead.

Dudley Observatory Skywatch line for Monday and Tuesday, July 25 and 26, written by Sue French.

On Monday the Sun rises at 5:40am and sets at 8:26pm, making its daytime less than the previous day by just 1 minute and 56 seconds. Tuesday’s sunrise and sunset come at 5:41am and 8:22pm, thus offering us a daytime 1 minute and 58 seconds shorter than Monday.

The slender crescent Moon is currently low in the early morning sky, rising in the northeast at 2:31am on Monday and 3:17am on Tuesday. It dips below the northwestern horizon in the evening sky at 6:43pm Monday and 7:33pm Tuesday.

Early birds with a good view of the northeastern horizon might be able to catch sight of the Moon showing off its Earthshine. Just as a full Moon makes our nighttime brighter, the Earth can brighten the part of the Moon that’s experiencing night. The Moon’s phases are opposite those of the Earth, so when the Moon is a slender crescent, the bigger and brighter Earth is nearly full in the Moon’s sky. All that light falling upon the Moon bathes its nighttime with a ghostly glow.

Nautical twilight ends at about 9:40pm on Monday and Tuesday. This is defined as the time when the center of the Sun is 12 degrees below the Earth’s horizon, a time when mariners can no longer distinguish the line between the horizon and the night sky. It’s also a good time to go outside and observe the sky, since the stars are then making their appearance.

Two great lights will dominate the sky at that time. The star Arcturus, in the constellation Boötes the Herdsman, will grace the west-southwestern sky, about halfway from the horizon to a point straight overhead. It’s the 4th-brightest nighttime star visible from anywhere in the world. Higher in the sky and a little to the east of south, the star Vega, in the constellation Lyra the Lyre, ranks as the 5th-brightest star. If you look carefully you might be able to tell that these two stars are not the same color. Vega shines nearly pure white, while Arcturus boasts a soft orange glow.

Tuesday night gives us a particularly bright passage of the International Space Station. It first appears low in the west-northwest at 10:45 pm and grows brighter as it climbs the sky. By the time it’s highest in the sky, at 10:48pm, the ISS will far outshine any star in the night sky. At that time it will have climbed about three-fourths of the way up the sky and will quickly fade as it enters the Earth’s shadow.

This is Dudley Observatory’s Skywatch Line for Friday, July 22, through Sunday, July 24, written by Sam Salem.

On Friday, Sun rises at 5:37am and sets at 8:26pm; Moon rises at 12:52am and sets at 3:40pm. On Saturday shortly before sunshine, see the delicate crescent of the old Moon shining above the stars of Taurus, the Bull, in the eastern sky. The Pleiades star cluster, also known as the Seven Sisters and the Hole in the Sky, will be poised several degrees above the Moon. The bright orange star Aldebaran will twinkle a fist’s diameter below. Binoculars will show the Hyades cluster, a triangle of many stars that outline Taurus’ face to the upper right of Aldebaran. The Bull’s two horns will be tilted downwards to the left.

Before the sky begins to brighten on Friday, the waning crescent Moon will allow you to find the tiny dot of the magnitude 5.8 blue-green planet Uranus in binoculars and backyard telescopes. The Pleiades cluster and reddish Mars will shine nearby. When the Moon rises after 1am, Uranus will be located a lunar diameter above the Moon. The Moon’s eastward orbital motion will carry it farther to Uranus’ lower left each hour. Uranus, in the constellation of Aries, is in the east before the first light of dawn, lower left of Mars.

Venus, at magnitude –3.9, continues to rise just as dawn begins. As dawn brightens, look for it low in the east-northeast. Using binoculars, try for orange Aldebaran increasingly far to Venus’ upper right. Also try to locate the Pleiades above Aldebaran. Brighter Capella shines farther to Venus’ upper left.

Mars, at magnitude +0.3 in Aries, rises around 1am and hangs high in the east-southeast as dawn begins. It’s about three fists lower left of bright Jupiter. Mars is still very small in a telescope, 8 arcseconds in apparent diameter.

Jupiter, at magnitude –2.6 at the Pisces-Cetus border, rises due east around midnight. It’s nearly at its highest in the south as dawn begins.

Neptune, magnitude 7.9 at the Aquarius-Pisces border, is high in the south-southeast before the first light of dawn, right of Jupiter.

Saturn, at magnitude +0.4 in western Capricornus, rises in the east-southeast in late twilight. It’s highest in the south in the two hours before dawn. Saturn’s rings appear roughly as wide as Jupiter’s disk.

Face south soon after dark and look for the next-brightest star near the Summer Triangle. Rasalhague, magnitude 2.0, is the head of Ophiuchus. You’ll find Rasalhague about equally far to the right of Altair and lower right of Vega. Altair is currently the Summer Triangle’s lowest star. Vega, nearly overhead, is its brightest. If you consider Rasalhague as the Fourth star of the Summer Triangle, then the “Summer Quadrilateral” covers a little more than twice the area of the Summer Triangle. Rasalhague is derived from Arabic, meaning “the head of the serpent” or the “head of the serpent bearer”. It is pronounced as “raesalheig”. Rasalhague is a binary star system.

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, July 20 and 21, written by Alan French.

The Sun rises at 5:35 A.M. and sets at 8:27 P.M. on Wednesday. On Thursday it rises at 5:36 and sets at 8:26. Thursday has 11 ½ minutes less daylight than a week ago.

The Moon reaches last quarter Wednesday morning and will start moving toward new. It will reach new, roughly between the Earth and Sun, on Thursday, July 28. The Moon, 54 % illuminated, rises at 12:07 A.M. Wednesday morning. On Thursday it rises at 12:29 A.M. Being past first quarter it appears only 44% in sunlight. By Friday morning moonrise isn’t until 12:53 A.M.

If you’re up before sunrise on Wednesday look for the Moon high toward the southeast. Jupiter will be to the right of the Moon, a bit higher, and a 16 ½ degrees away. By Thursday morning the Moon’s eastward motion among the stars will have moved it lower and farther from Jupiter.

Brilliant Venus continues to grace the morning twilight sky, appearing low in the east northeast. It now shines at magnitude -3.9.

By 10:30 P.M. the last vestiges of evening twilight are gone and the sky is nice and dark. High in the east, almost overhead, is the bright star Vega, fifth brightest in the night sky and shining at magnitude 0.02. Like many of the brighter stars, Vega is bright partly because it is one of our closer neighbors, lying only 25 light years away, but is also one of our most luminous close neighbors, about 40 times more luminous than our Sun. From Vega our Sun would shine at magnitude 4 and be far less conspicuous than Vega in our sky.

Vega is the brightest star in the constellation Lyra, the Lyre. Lyra is one of the smaller constellations. In terms of area, it comes in at number 52 of the 88 constellations. It is, however, easy to recognize, and contains a couple of popular and easily found sights for amateur astronomers and their telescope.

If you’re looking at Vega high in the east, you’ll see a parallelogram of stars of about equal brightness to Vega’s lower right. A single star lies to Vega’s lower left, completing the pattern of Lyra.

The single star is Epsilon Lyra, a double star the is nicely spit through a telescope into two components, Epsilon1 and Epsilon2. If you have good eyesight, you can see it as two stars by eye. If you can’t resolve the two by eye, binoculars will do the trick. Its real claim to fame is that each star is also a double star, each split into a pair under steady skies with a telescope and a bit of magnification. A magnification of 60 or 70 should show all four stars, but on some nights you might need twice that. To amateur astronomers, it is known as the “Double-Double.”

There’s another popular target in Lyra, popular because it shows well and is easy to find. The Ring Nebula, a planetary nebula, is almost exactly in the middle of the gap between the two stars in the short side of the parallelogram farthest from Vega. At around 50 power it looks like a small Cheerio or ring. Higher powers may reveal that the inside of the ring is not as dark as the sky surrounding it, but glows with faint nebulosity. It’s a popular target for astrophotographers.