The new nova is located in Delphinus alongside the familiar Summer Triangle outlined by Deneb, Vega and Altair. This may shows the sky looking high in the south for mid-northern latitudes around 10 p.m. local time in mid-August. The new object is ideally placed for viewing. Stellarium
Looking around for something new to see in your binoculars or telescope tonight? How about an object whose name literally means “new”. Japanese amateur astronomer Koichi Itagaki of Yamagata discovered an apparent nova or “new star” in the constellation Delphinus the Dolphin just today, August 14. He used a small 7-inch (.18-m) reflecting telescope and CCD camera to nab it. Let’s hope its mouthful of a temporary designation, PNVJ20233073+2046041, is soon changed to Nova Delphini 2013!
This map shows Delphinus and Sagitta, both of which are near the bright star Altair at the bottom of the Summer Triangle. You can star hop from the top of Delphinus to the star 29 Vulpeculae and from there to the nova. Or you can point your binoculars midway between Eta Sagittae and 29 Vul. The “5.7 star” is magnitude 5.7. Stellarium
Several hours later it was confirmed as a new object shining at magnitude 6.8 just under the naked eye limit. This is bright especially considering that nothing was visible at the location down to a dim 13th magnitude only a day before discovery. How bright it will get is hard to know yet, but variable star observer Patrick Schmeer of Germany got his eyes on it this evening and estimated the new object at magnitude 6.0. That not only puts it within easy reach of all binoculars but right at the naked eye limit for observers under dark skies. Wow! Since it appears to have been discovered on day one of the outburst, my hunch is that it will brighten even further.
Here’s a reverse “black stars on white” map some observers prefer for greater clarity. Stars are shown to 9th magnitude. Tycho visual magnitudes shown for 4 stars near the nova. The nova’s precise position is RA 20 h 23′ 31″, Dec. +20 deg. 46′. Created with Chris Marriott’s SkyMap
The only way to know is to go out for a look. I’ve prepared a couple charts you can use to help you find and follow our new guest. The charts show stars down to about 9th magnitude, the limit for 50mm binoculars under dark skies. The numbers on the chart are magnitudes (with decimals omitted, thus 80 = 8.0 magnitude) so you can approximate its brightness and follow the ups and downs of the star’s behavior in the coming nights.
Despite the name, a nova is not truly new but an explosion on a star otherwise too faint for anyone to have noticed. A nova occurs in a close binary star system, where a small but extremely dense and massive (for its size) white dwarf grabs hydrogen gas from its closely orbiting companion. After swirling about in a disk around the dwarf, it’s funneled down to the star’s 150,000 degree F surface where gravity compacts and heats the gas until it detonates like a bazillion thermonuclear bombs. Suddenly, a faint star that wasn’t on anyone’s radar vaults a dozen magnitudes to become a standout “new star”.
Model of a nova in the making. A white dwarf star pulls matter from its bloated red giant companion into a whirling disk. Material funnels to the surface where it later explodes. Credit: NASA/CXC/M. Weiss
Novae can rise in brightness from 7 to 16 magnitudes, the equivalent of 50,000 to 100,000 times brighter than the sun, in just a few days. Meanwhile the gas they expel in the blast travels away from the binary at up to 2,000 miles per second. This one big boom! Unlike a supernova explosion, the star survives, perhaps to “go nova” again someday.
Closer view yet of the apparent nova showing a circle with a field of view of about 2 degrees. Stellarium
I’ll update with links to other charts in the coming day or two, so check back.
A thin lunar crescent rises beneath the Pleiades star cluster tomorrow morning at dawn. This map shows the sky facing northeast about 4 a.m. local time. Maps created with Stellarium
The sky can be a showy stage with big-time events like eclipses, meteor showers and the occasional bright comet, but most nights have a quiet beauty that whispers instead of shouts. The contrast between hype and hush is no more apparent than on the 4th of July – American independence day celebration – when we gather at a park or hilltop to watch the fireworks boom and flash across the heavens.
But there are other interesting things — some quiet fireworks — you can see in the sky to see while you are waiting for the holiday fireworks.
You can watch a less flashy but equally satisfying July 4th event as soon as tomorrow morning about the time the first bird lifts its voice at dawn. Look northeast to find a thin crescent moon dangling below the Seven Sisters star cluster. Also called the Pleiades, the cluster is a highlight of the winter evening sky. Though it seems out of place now at the height of summer, the Sisters remind us that nothing stands still. With the solstice behind us, winter’s already buckling his boots.
As you relax before the fireworks begin, look for two bright stars and two bright planets in the west and southwest skies. You can fit about three fists held at arm’s length between Saturn and Arcturus.
While you’re waiting for the show to begin tomorrow night, take a look around the twilight sky and see how many celestial luminaries you can spot. If you’ve got kids in tow, share the view with them, too.
The brightest natural object in the sky will be Venus, glimmering low above the western horizon. Much further up in the southwest, look for a tall, skinny triangle outlined by orangy Arcturus, highest of the three, along with Saturn and Spica.
Facing east brings the three bright stars of the Summer Triangle in to view.
Twist around to face east to find another triangle, this one named after the summer season. Halfway up is Vega, the 5th brightest star in the sky, shining white and bright as burning magnesium. Below it you’ll spot the other Summer Triangle members, Altair in Aquila the Eagle and Deneb in Cygnus the Swan better known as the Northern Cross.
These bright stars and two planets coalesced from gas and dust millions to billions of years ago. Much has happened beneath their gaze, from the first stirrings of humankind to the crackle and boom of fireworks on a starry evening.
Fireflies make green trails of light during a time exposure on a July night. Jupiter is at upper left. Credit: Bob King
Bioluminescent stars flash across the night landscape these July nights. Fireflies or lightning bugs provide a source of wonder for many of us living in the eastern half U.S. and Canada. Did you know dark skies may be as important to them as they are to you and I?
To stoke their yellow-green fires, the bugs – they’re really beetles – cook up light through a series of chemical reactions within their abdomens.
Adult Photurus firefly. Fireflies produce a cool light by combining oxygen in the air with the chemical luciferin. Credit: Bruce Marlin
Oxygen from the air combines with a chemical fittingly named luciferin. Luciferin next hooks up with the energy molecule ATP to form another molecule that when combined with oxygen yields a flash of green, yellow or amber light, depending upon the firefly species.
Fireflies compete with the stars from a dark location near Duluth, Minn. two nights ago. Each species has its own specific flash pattern. Credit: Bob King
The males perform the flash-dance moves, wiggling and zigging about to attract the females, who typically remain on the ground hidden among blades of grass. Each species has its own flashing pattern. When a female finds a male’s flashes suitably alluring, she winks a flash back. Back and forth communications soon bring the two together to make more fireflies.
Firefly light emits no heat, making it one of the most efficient light sources known. A standard incandescent light bulb converts electricity into 10% light and the rest as heat; fireflies transform 100% of their chemical energy into light. These insects do not waste photons.
One of my favorite memories from childhood was running around on summer nights collecting fireflies in a glass jar. Credit: Bob King
Every night I’m out under the July stars at least one firefly manages to land within the telescope tube and create a surprise supernova. If I inadvertently switch my LED flashlight on and off at the right rate, more than a few of them will land right on top of the device in a futile attempt to mate.
Urban sprawl and accompanying light pollution is an issue for both astronomers and fireflies. This view shows the light dome from the city of Duluth, Minn. 20 miles north of town. Credit: Bob King
One thing fireflies and skywatchers have in common is love of the night. To appreciate the twinkling heavens, we either escape to the countryside or do our best to contend with the lights in town. Firefly numbers are declining across the U.S. and the world, and though no one’s certain yet why, there’s both anecdotal and scientific evidence suggesting that loss of habitat and light pollution are to blame.
Example showing poorly shielded light fixtures. With nothing to contain or direct the light, it shines where it’s not needed – straight up! Credit: Bob King
Urban sprawl has comprised the habitats of many wild creatures not just fireflies. Sprawl also brings increased lighting, much of it poorly shielded and on all night. Fireflies avoid heavily lit areas for obvious reasons – light pollution interferes with their ability to see each others’ flashes. Even car headlights can throw them off rhythm. According to a 2008 story in the Boston Globe, controlled experiments have shown that brighter lighting levels cause fireflies to mate less often.
Full cutoff lighting fixtures like these put light where it’s needed – on the road – and not out to the sides or up in the sky. Credit: Bob King
We all can help ensure our favorite bioluminescent buddies remain around for a long time. Turning off your own yard light not only helps you to see more stars but makes it easier for fireflies to find their mates. If you absolutely need illumination, consider one of these efficient shielded light fixtures that puts light where you want it while eliminating the glare that frustrates fireflies and stargazers alike. To learn more about good lighting and keeping the sky dark, check out the International Dark Sky Association.
Billions of aspen seeds float by the sun on tiny hairs creating a multicolored corona around the sun yesterday. To see and photograph the rings, I used a power pole to block the sun. Credit: Bob King
For the past two weeks puffy clumps of seeds have been riding the air in my town. You can’t avoid them. Open a door and they’ll breeze right in. Take a deep breath and you’d better be careful you don’t take a few down the windpipe.
Every June the many aspen trees that call northern Minnesota home release their booty of tiny seeds that parachute through the air on tiny clusters of hairs. And while they all have no particular place to go, their combined and unintentional effect is to create a series of beautiful colored rings about the Sun called a corona.
A single aspen seed (left) only about 1 mm across embedded in a cottony fluff of tiny hairs. At right is a spider web. Both show colors caused by bending and interference of light, a phenomenon called diffraction. Credit: Bob King (left) and Andrew Kirk
Reach your hand up to block the Sun and if your eyes can stand the glare of blue-white sky, you’ll see bazillions of tiny flecks a-flying. If you were to capture one and study it up close, you’d see it diffractlight in tiny glimmers of chrome green and purple.
When light from the sun or moon strikes a tiny water droplet, speck of pollen or aspen seed hairs, it’s scattered in different directions. Some of the scattered waves reinforce each other to make a bright ring of light in the sky while other waves cancel each other out to create a dimmer ring. A series of alternating rings around the sun is called a diffraction pattern or corona. Credit and copyright: Les Cowley www.atoptics.co.uk
Light is always getting messed with by tiny things. When it comes to aspen seeds, as rays of light – made of every color of the rainbow – bend around the hairy obstacles they interfere with one another like overlapping, expanding wave circles in a pond. Some of the waves reinforce each another and others cancel out. Our eyes see a series of colored fringes that flash about the tiny hairs.
Most halos are circular but pollen halos like this one around the moon often have unusual shapes like this oval with bulging sides and top. Credit: Bob King
The exact same thing happens when light has to step around minute water droplets, pollen grains and our hairy aspen fluffs when they’re drift through the air overhead. Overlapping wavelets of light “interfere” with one another to form a series of colorful concentric circles called a solar corona. While the same in name, this corona is an earthly one unrelated to the huge, hot coronal atmosphere that surrounds our star.
Oil-coated water droplets also show beautiful diffraction colors for a similar reason as clouds and pollen do . Light reflecting from the bottom surface of the oil film interferes with light reflecting off the top of the layer to create shifting patterns of color. Credit: Bob King
The ones created by seed hairs and pollen require clear skies and a safe way to block the Sun’s overwhelming light. My filter of choice is the power pole mostly because they’re handy. Sunglasses help to reduce the glare and eye-watering wincing.
While I can’t be 100% certain the chromatic bullseye was painted by poplar hair deflections – there’s always a chance pollen played a part – I’ve seen similar displays when the seeds have passed this way before.
Iridescent clouds are another form of a corona formed by minute water droplets diffracting light. Credit: Bob King
Coronas created by water droplets in mid-level clouds are much more common, and the familiar “ring around the sun” or solar halo is an entirely different creature. Here, light is bent or refracted through billions of microscopic six-sided ice crystals.
I figure that if the night is cloudy, the play of light and clouds in the daytime sky often makes for an enjoyable substitute.
The view of Kitt Peak National Observatory, as seen from 1 mile below the summit.
Greetings, from the Kitt Peak National Observatory, in Arizona! I’m here on a weeklong observing run, which is arguably the coolest and hardest part of the job.
Kitt Peak rests on the Quinlan Mountains, 6,880 feet above sea level and 55 miles southwest of Tucson. When you begin your drive up the mountain, you first see a beautiful panorama of glittering white domes. There are 26 telescopes on the Mountain.
The Mayall 4-meter telescope quickly catches your eye – the colossal giant that towers over the rest. As you continue your drive, a radio telescope can be seen on the left, followed by various signs stating that cell phone use is strictly prohibited. Observing runs here require radio silence, and a great chance to escape.
At the top of the mountain, two telescopes stand apart from the rest – the McMath-Pierce Solar Telescope and the WIYN observatory. The solar telescope reflects sunlight through a tunnel that leads underground. The WIYN observatory has an octagonal shape for a dome.
This is my third trip to Kitt Peak, but my first chance to observe on the Mayall 4-meter telescope. The first thing to know about the 4-meter is that it is a colossal maze. Literally. There are 16 stories of rooms, now obsolete and out of date, before reaching the base of the telescope itself.
The dome of the 4-meter Mayall telescope (left) as well as the telescope itself (right).
These rooms include old darkrooms, instrument rooms, machine rooms, classrooms, dormitories, game rooms, and other mysteries. We’ve been joking most of this week that Hollywood should rent out the 4-meter for a fantastic horror film. Just think: The Big Bang Theory meets Psycho.
On our first day here, my colleague and I managed to get pretty lost. To reach the telescope you have to take two different gated and locked elevators. But when we finally made it to the control room, we realized that this room alone is much more of maze than the building.
The control room consists of 4 computers, 16 monitors, 3 personal laptops, 4 tv screens, and an array of controls that operate the telescope. Eventually we became very comfortable floating from monitor to monitor.
The control room for the 4-m Mayall telescope. Dr. Mike DiPompeo is taking images throughout the night.
Here is what a typical day on an observing run looks like.
We typically wake up a little after noon and grumpily head to the dining hall for coffee. Breakfast (or lunch) runs until about 1 pm.
In the late afternoon, we take a few flat field calibrations – images of a white screen, which is uniformly lit up. Any variations in the final image are due to variations in the detector or distortions in the optical path. At the end of the day, you can divide your science images by your flat field images, in order to achieve much cleaner images.
Shortly thereafter, the dewar is filled with liquid nitrogen. This keeps the instrument cool (approximately -100 degrees Fahrenheit), as any thermal current can cause added noise.
After a quick dinner we return to the telescope. At this point sunset is approximately 2 hours away, but it’s already time to open the dome. When you’re standing next to the telescope, an opening dome sounds like a freight train screeching to a stop. It’s slightly terrifying, but it is by far one of my favorite sounds. It signifies that for the rest of the night you’re in control of this phenomenal instrument, which has the power to discover the secrets of the Universe.
After two hours of various preparations – making sure the telescope is pointing correctly, guiding correctly, etc. – we “get on sky.” Throughout the night the telescope operator controls the telescope, moving it to the fields we would like to observe, while we are in charge of taking the images by verifying the exposure time, filters to use, etc.
If everything goes smoothly the night is pretty easy. The telescope operator moves from target to target while we continuously take images. This means that we end up sitting in front of a computer screen, pressing enter every 300 seconds in order to start a new exposure. That’s really all it takes! Of course you should keep checking on your images in order to verify that they look good.
Around midnight it’s time for night lunch, a packed lunch that the dining hall provides. A little extra protein helps make the long nights more bearable. And then you push through, making coffee if necessary. The challenging part is staying awake throughout the night. It’s amazing how hard simple calculations can be when dawn is approaching.
At the end of the night you step outside and save for the flickering glint of Tucson’s city lights, the only noticeable light is found by looking up into the night sky. The stars here are brilliant, and the Milky Way is astonishing. After spending an entire evening stuck in a black box, it’s a wonderful reminder of what it’s all about: the night sky.
I observed with Dr. Mike DiPompeo, who concurred on what I noticed about the observing experience.
“When you first get into astronomy you’re in awe of the beauty of the night sky, compelled and driven by it,” DiPompeo told me. “But it can be easy to forget in the day to day business of being an astronomer – sitting at a computer, writing code, going through the data, reading papers – that your job is to understand that beauty. Observing reconnects you with the night sky.”
My favorite part of an observing run occurs in the morning – on the walk from the telescope to the dorm, when a yellow arch of light first appears above the horizon. Kitt Peak provides fantastic sunrises. And you really have to soak in every last ray of sun, before you crawl into bed in a very dark room.
One of many beautiful sunrises.
Observing runs lie at the root of pure research. You spend the long nights collecting data, then the months or years analyzing the data, and finally hope that a cool result comes from all the hard work.
Starting Friday the moon will be your guide to Venus' return to the evening sky. This map shows the sky facing west-northwest about 30 minutes after sunset across the middle of the U.S., but it's useful from 30-50 degrees north. Venus will be 4 degrees high at the time. Friday's moon is very thin! Stellarium
Has Venus finally come out of hiding? For the past couple months it’s kept close to the sun, hidden in its glare, but come Friday, sky watchers in mid-northern latitudes may get their first shot at seeing the planet’s return to the evening sky.
It won’t be easy, but you’ll have help from the knife-edged crescent moon. Like a spring bloom raising its head from the dark earth, Venus will poke just 4 degrees above the western horizon a half hour after sunset. The moon will be about 2 degrees to the lower left of the planet. Seeing both requires a wide open view to the west and a clean, cloudless sky. It also helps to know when the sun sets for your location – easily found by clicking HERE.
Most any binoculars will prove useful for seeing Venus in twilight this week. One of my (inexpensive) favorites is a pair of Nikon Action 8x40s. Once you spot the planet in binoculars, try to see it with your naked eye. Credit: Bob King
Take along a pair of binoculars. They’ll help fish out both moon and planet in the bright twilight sky. It’s also advantageous to arrive at your viewing spot a little early. Enjoy the sunset, and then take a minute to make sure you’re binoculars are focused at infinity. If you don’t, Venus will be a blur and much harder to find. I usually focus mine on a cloud or the very farthest thing out along the horizon.
Once you’re all set, point your binoculars in the sunset direction and slowly sweep back and forth. Venus will be a short distance to the left or south of the brightest glow remaining along the horizon. Since most binoculars have a field of view of 4 or 5 degrees, when you place the horizon at the bottom of the view, the moon should appear in the middle of the field and Venus up near the top. Look higher and lower and farther left and right to be thorough. Once spotted in binoculars, take the visual challenge and see if you can find it without optical aid.
Venus punctuates a colorful sky low in the west at dusk in August 2008. Credit: Bob King
If you succeed, you’ll be rewarded with an elegant eyeful. Swamped in skylight, Venus will appear unusually meek but still possess its classic fiery brilliance. The newborn crescent will float just a degree and a half (three full moon diameters) away. From the U.S. east coast, the moon will be just 24 hours old; from the west coast 27 hours. Seeing such a young moon is a rarity in itself, but in the company of Venus that much finer.
Let’s say conditions aren’t ideal and you miss the pair on Friday. Well, try again on Saturday. The moon will be higher and much easier to see. Use it as a bow to shoot an imaginary arrow horizon-ward to Venus. And did I mention Jupiter? The planet that cheerily lit up our winter nights is now departing in the west. Watch for it to have a close encounter with Venus on the nights of May 27-28.
With its perpetual clouds, Venus would be a most distressing planet to any skywatcher unfortunate enough to live there. Yet it’s those same clouds that make it the most brilliant planet in the solar system seen from Earth. Clouds reflect sunlight splendidly. Combined with Venus’ proximity to Earth, it’s no wonder the planet earned the title of goddess of love and beauty.
As Venus and Earth revolve around the sun at different speeds, we see Venus from a constantly changing perspective. In May, the planet is slightly to the left or east of the sun and looks like a miniature full moon at dusk. Come Halloween it resembles a half-moon and a crescent at Christmas. Credit: Bob King
In the first 3 months of this year, Venus remained close to the sun in the morning sky and difficult to see. Then on March 28, it passed behind the sun on the opposite side of Earth’s orbit; astronomers call the lineup superior conjunction. Seen from Earth, Venus looked like a tiny full moon. We’re now about 6 weeks past conjunction and the planet has begun to peek out into the evening sky. At 98% illuminated, it still looks nearly full through a telescope, but that will change in the coming months as Venus approaches Earth in its speedier orbit. Watch for the goddess to grow larger in apparent size while at the same time slimming down her phase from full to half to crescent. Good luck getting re-acquainted this weekend!
Here’s the latest update on what’s up in the night sky from Jane Houston Jones at the Jet Propulsion Laboratory. The Moon will be your guide on how to spot the spring constellations and other popular astronomical sights this month including nebulae, a galaxy trio and the site of a recent planetary discovery.
Saturn is one of the most striking objects to see through a telescope, and it is now at its brightest in the night sky as it reaches opposition from the Sun. This is when Earth stands mostly perfectly in line between Saturn and the Sun. It is when Saturn is brightest (at magnitude +0.3), closely approximating famous “first magnitude” stars like Betelgeuse. Also, it is when Saturn is out all night long. Continue reading “Saturn Reaches Opposition on April 28”
The orbital path of the International Space Station appears to take it through the Moon, as seen from the UK on April 16, 2013. Credit and copyright: Dave Walker.
What a great image! Astrophotographer Dave Walker combined seven 30-second shots of the ISS as it cuts through the sky, and it appears to slice right through the Moon! Dave used a a Canon 600D, Samyang 8mm fish-eye lens, and Vixen Polarie.
Now through the end of April provides some great sighting opportunities in the northern hemisphere for seeing the International Space Station as it flies overhead — and over your backyard! Some evenings there are even two passes. See below for another great panorama of an ISS pass, as well as information on how to find out when you can see it. It’s always an amazing sight!
A view of the International Space Station over St. Pölten, Austria on April 15, 2013. A panorama of 13 single shots, each with 25 sec. exposure-time. Credit and copyright: Ma Brau via Flickr.
NASA has a Skywatch page where you can find your specific city to look for satellite sighting info.
Spaceweather.com, has a Satellite Tracker Tool. Just put in your zip code (good for the US and Canada) to find out what satellites will be flying over your house.
Heaven’s Above also has a city search, but also you can input your exact latitude and longitude for exact sighting information, helpful if you live out in the country.
Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.
Comet C/2011 L4 PANSTARRS on the evening of April 9, 2013 from Austria. Dust released when the sun vaporizes the comet's ice is pushed back by the pressure of sunlight to form the tail. Click to enlarge. Credit: Michael Jaeger
It’s falling out of the news but Comet PANSTARRS still lives! You can still see it in a clear sky near you with nothing more than a pair of binoculars. And thanks to guidance from the bright zigzag of Cassiopeia, it’s easier than ever to find. Would that we had had this star group to point up comet-ward in March when PANSTARRS was brightest!
The comet marches along through Cassiopeia the Queen in April. The map shows the evening sky facing northwest about 90 minutes after sunset. Comet positions are shown every 5 nights. Stellarium
Start looking about 75-90 minutes after sunset or the same amount of time before sunrise. Yes, the comet is visible now at both dusk and dawn. Currently it shines at about 4.5-5 magnitude and might still be faintly visible with the naked from a very dark sky location. In 35-50mm binoculars it will look like a faint, fuzzy streak of light with a brighter head. Telescopes still give a wonderful view of the bright nucleus and shapely tail.
While the northern U.S., Canada and Europe have good views of PANSTARRS at both dusk and dawn, sky watchers in the southern U.S. have their best views at dawn. This map shows the sky at the start of dawn facing northeast about 90 minutes before sunrise. Stellarium
The other night a student who helps run our local planetarium described it as looking like a “real comet” through the telescope, the way textbook and online photos had led him to anticipate. Binoculars or telescope will show a misty, plume-like tail, but wide-field, time-exposure photography reveals the comet’s unbelievably broad fan of dust.
Comet PANSTARRS moves along a steeply tilted orbit that takes it far above and below the plane of the planets. Right now it’s high above Earth’s north pole and we see its tail broadside. The comet takes about 106,000 years to complete an orbit around the sun. Credit: NASA/JPL/Bob King
The reason for this unusual appearance has much to do with perspective. PANSTARRS is sailing back into deep space directly above the plane of the planets. With the tail blown back by the pressure of sunlight, we look up and across a distance of more than 125 million miles (201 million km) to see it spread like a deck of cards across the constellation Cassiopeia.
Comet PANSTARRS a week ago when it passed near the Andromeda Galaxy (at left). Details: 300mm f/2.8, ISO 800 and 90-second exposure. Credit: Bob King
In the northern U.S., Cassiopeia is higher up in both morning and evening skies and easy to spot. Once you’ve found its familiar shape, focus your binoculars on the brightest star nearest the comet, and slowly work your way in its direction. Skywatchers in the northern U.S., Canada and Europe are favored because Cassiopeia is a northern constellation and higher up in the sky at both dusk and dawn. Observers in the southern U.S. will get their best views around the start of dawn.
