science – The Amazing Sky

April 30, 2025April 30, 2025

Touring the Constellations of Spring

Join me in a guided tour of the famous (and not so well known!) constellations of the northern spring sky.

The northern spring sky lacks the splendour of bright patterns such as winter’s Orion or summer’s Cygnus, but it is still well worth getting to know. The Milky Way is out of sight, and in its absence we are left with fewer bright stars to dazzle us at night. But we are treated to the year’s best views of famous constellations such as Ursa Major, Leo and Virgo.

Now, I am talking about the sky of the northern hemisphere, where April and May brings spring, and places the Big Dipper high overhead. While some of these constellations can be seen from the southern hemisphere, they appear to the north, low and “upside-down” from the views I present here. And April and May are autumn months.

Let’s start with the “big picture.” (Tap on images to bring them up full screen.)

NOTE: I shot all these images during a run of fine nights in mid-April 2025 with a 15-35mm zoom lens on a Canon EOS R camera, and on a Star Adventurer tracker. Separate exposures through a Tiffen Double Fog 3 filter added the star glows.

This image, in labeled and unmarked versions, presents a wide view of the spring sky from horizon to well past the zenith overhead. The key pattern to look for is the Big Dipper, at its highest in northern spring. In the UK and Europe it is known as the Plough or Wagon. Look way up to find it first.

Its Pointer Stars in the Bowl famously point north to Polaris. But here I show the other pointer line off the Bowl, to the south, to Leo the Lion. It is well known as one of the constellations of the Zodiac. Leo is marked by one of the brightest spring stars, Regulus.

Use the Handle of the Dipper to arc downward, to locate the brightest star of spring, Arcturus, shining with a yellow light. Keep that line going south and you’ll come to a dimmer and bluer star shining in the south. That’s Spica, the brightest star in Virgo, the Zodiac constellation east of Leo.

Now let’s take a closer look at selected areas.

This is still a wide view, looking up and high in the south. There’s the Big Dipper/Plough at top. It is not a constellation. It is an “asterism” of seven stars within the large constellation of Ursa Major, the Great Bear. With a little imagination you can join the dots to make a bear (many northern cultures did so). Except we draw him with a long tail, which bears do not have!

The paws of the Bear are marked by a trio of double stars: Alula Borealis and Australis, Tania Borealis and Australis, and Talitha and Talitha Australis. The names come from Arabic words for “first,” “second,” and “third” as these sets of double stars are collectively called the Three Leaps of the Gazelle in Arabic sky lore. Once you see them you’ll be surprised at how distinctive they are.

Below Ursa Major is Leo, a pattern that does look a little like a sitting cat. Its bright star Regulus was named by Copernicus, from a Latin word for “little king.” But Regulus has long been known as the heart of the Lion.

To the east lies brighter Arcturus, a name that means “bear watcher,” as it and its host constellation Boötes, the Bear Herdsman, are tied to Ursa Major and Minor in Greek mythology.

Here I frame Leo, but also two of the constellations that flank him: Cancer the Crab to the right (or west) and Coma Berenices to the left (or east). Each contains a bright naked eye cluster of stars:

Messier 44 or the Beehive cluster in Cancer, the faint Zodiac pattern west of Leo. When I shot this image in mid-April 2025 red Mars was just entering Cancer.
and Melotte 111 in Coma Berenices. At one time this clump of stars easily visible to the naked eye was considered part of Leo, as the tuft on the end of his tail. The area was broken off as its own constellation in the 3rd century BCE, and named for Queen Berenice of Egypt, and for her legendary hair (“coma”).
Together, the obvious pattern of Leo and the star clusters that flank him form one of the spring sky’s most notable sights.

The head of Leo is marked by a curving arc of stars popularly called The Sickle. Or it is thought of as backwards Question Mark, with Regulus the dot at the bottom. Leo is one of the oldest constellations, as there are records of this pattern dating back to 4000 BCE in Mesopotamia.

More modern is the obscure pattern above it, Leo Minor, the Little Lion. It was invented by 17th century star chart maker Johannes Hevelius, to fill in a blank area of sky. Even in a dark sky, it is tough to make out its innocuous pattern between Leo and Ursa Major.

Canes Venatici, Coma Berenices and Boötes

Another obscure pattern created by Hevelius lies below the Handle of the Big Dipper. A sparse pattern of stars marks Canes Venatici, the Hunting Dogs that belong to Boötes to help him herd bears! While not much to look at with the naked eye, Canes Venatici does have superb targets for telescopes, such as the double star Cor Caroli and very red star La Superba.

Below the Dogs lies Berenices’ Hair, home to the star cluster Mel 111, but also the North Galactic Pole (NGP). This is the point 90º away from the plane of the Milky Way and the Galactic Equator seen in our winter and summer skies. But in spring we look straight up out of our Galaxy, to many other telescopic galaxies that inhabit Coma and Virgo, our next stop.

Below Leo and Boötes lies the Zodiac pattern of Virgo, usually thought of as the reclining Greek goddess of agriculture and the harvest. Spica is easy to see, but the sprawling pattern of the rest of Virgo is not so obvious. It takes a dark sky to pick out the other fainter stars of the goddess.

Easier to see, despite its low altitude from northern latitudes (it skims my horizon), is the quadrilateral pattern of Corvus the Crow, a constellation that dates from the 2nd century CE and the star catalogue of Ptolemy. The Crow sits on the tail of Hydra the Water Snake, a long zig-zag line of stars that is only partly contained here. The head of Hydra, off frame to the right here, is in the earlier image of Leo and Cancer.

Another pattern riding the back of Hydra is Crater the Cup, associated with Corvus and Hydra in a Greek myth in which the Crow is sent to fetch water for Apollo but fails. Apollo flings the Crow, Cup and Snake into the sky. Angering the gods could get you immortalized in the sky!

Heading back north above Virgo, we return to the kite-shaped pattern of Boötes above Arcturus, the brightest star in the northern half of the sky. Coming up later on spring evenings, and to the left is a semi-circle of faint stars, the Northern Crown, or Corona Borealis, another of Ptolemy’s patterns from the 2nd century. The crown belongs to the princess Ariadne.

Astronomers have been watching Corona Borealis closely in recent months, waiting for a recurrent nova star to explode and add a new jewel to the Crown. So far, no luck. T CorBor remains stubbornly dim.

To the east of Corona is the H-shaped pattern of Hercules, the Roman name for the Greek hero Heracles. Among his many labours and conquests, he slewed Cancer the Crab and Leo the Lion.

Returning down south and scraping the horizon from my northern latitude late on spring nights are the next two constellations of the Zodiac east of Virgo: Libra the Scales and Scorpius the Scorpion.

Libra is a faint pattern but with the wonderfully named stars Zubeneschamali and Zubenelgenubi, meaning the northern and southern claws, as these stars were once considered part of the Scorpion. However, Libra has long been seen as a balance or scales for meting out justice. It is the only Zodiac constellation that is an inanimate object.

Scorpius is one of the few patterns that looks like what it is supposed to be, though here I see only the northern part of the constellation. His curving tail has yet to rise as the Milky Way comes into view low in the south just before dawn this night. The bright orange star is Antares, the heart of the Scorpion, set in an area rich in dark and colourful nebulas.

The appearance of Scorpius signals the return of the Milky Way to the sky, and the rise of the summer constellations.

But no astronomical life is complete without getting to know the patterns of spring. Clear skies and happy stargazing!

— Alan, April 30, 2025 (amazingsky.com)

December 9, 2024December 20, 2024

The Great Comet Chase of 2024

A plan to shoot the promised bright comet of 2024 paid off, with fine views at dawn and at dusk of the best comet since 2020.

Comets are always a gamble. Any new comets discovered, the ones that usually become the brightest, have no track record of performance. Predictions of how bright a new comet might appear are based on what a typical comet should do. But comets can outperform expectations and dazzle us, or they can fizzle and fade away.

In late 2023 it was clear that a then newly-discovered comet, C/2023 A3, named Tsuchinshan-ATLAS after the observatories where it was co-discovered, had the potential to perform in late 2024.

The low angle and position of the comet from home in Canada in the late September dawn sky, simulated in StarryNight software.

Knowing where it would be in the sky (that trait of a comet can be predicted with accuracy!) I planned a field trip to the U.S. desert Southwest for late September and early October 2024. From farther south the comet would be higher than it would be from home (shown above), and over spectacular landscapes.

I had visions of another Comet NEOWISE from July 2020. As my blog from 2020 shows, we saw that photogenic comet well from our northern latitude in Canada, as it skimmed across the northern horizon. Tsuchinshan-ATLAS would require a chase south.

September 26 & 27 — at Bryce Canyon, Utah

In late September 2024 the comet would be inbound, approaching the Sun and in the morning sky. What better eastern scene than overlooking Bryce Canyon in Utah, where I had been a year before, for the October 14, 2023 annular eclipse of the Sun in the morning sky. (Click the link for my eclipse chase blog.)

I was fortunate to get two clear mornings, both from the Fairyland Canyon viewpoint, just a short walk from the parking lot to carry camera gear and tracking mounts.

Comet C/2023 A3, Tsuchinshan-ATLAS, at dawn over Bryce Canyon, on the morning of September 27, 2024.

My first look at the comet on September 27 was on the day the comet was at perihelion, closest to the Sun in its orbit, though not in the sky at our viewing angle from Earth.

The comet was just visible to the unaided eye, but was obvious on the camera view screen, even amid the bright twilight. I had to shoot fast as the window between “comet rise” and the sky brightening too much was only a few minutes long.

Comet C/2023 A3, Tsuchinshan-ATLAS, rising in the twilight over Bryce Canyon, on September 28, 2024.

Knowing better what to look for, I caught the comet a little sooner the next morning on September 28, and so the tail appeared longer and more impressive as it rose above the distant mountains. A group of other local photographers arrived just a few minutes too late both mornings, and so struggled to just sight the comet, let alone photograph it.

This vertical panorama takes in the nebula-rich northern winter Milky Way over the formations of Bryce Canyon National Park, from the Fairyland Canyon viewpoint.

But I had arrived extra early, to shoot a vertical panorama (above) of the winter Milky Way over the canyon formations below. This and the comet images were shot with the aid of a sky tracker to follow the stars, but with the tracker off for separate shots of the ground.

So I had bagged the comet at Bryce! On to the next stop.

September 28 & 29 — at Monument Valley, Utah

There’s no more iconic or famous landscape in the American West than the buttes of Monument Valley, on the Navaho Tribal Lands on the Arizona/Utah border.

This panorama from the Navaho Tribal Park at Monument Valley shows the evening twilight sky looking east opposite the sunset to the rising dark blue arc of Earth’s shadow cast on the atmosphere. The shadow is rimmed with a pink “Belt of Venus” tint from sunlight still hitting the upper atmosphere.

A clear first evening provided a fabulous view of the arc of Earth’s shadow across the eastern sky from the viewpoint near the aptly named The View Hotel.

This is a panorama of the sunrise scene at the Navaho Tribal Park, Monument Valley, Arizona, taken just after sunrise with the low Sun lighting the iconic buttes and mesas of the Valley. The West and East Mittens are at left; the Sun was behind Merrick Butte at centre, and lighting Mitchell Mesa at right.

A wonderful sunrise on my second morning there made for a spectacular panorama. But while clouds created fine sunrise lighting, they aren’t conducive to seeing comets!

Comet C/2023 A3, Tsuchinshan-ATLAS (at centre), is rising in the dawn twilight over Monument Valley, Arizona on the morning of September 30, 2024. The comet is rising just south (right) of Merrick Butte.

A band of clear sky near the horizon allowed me to catch the comet rising to the right of Merrick Butte, as seen from a spot south of The View from where I had calculated the comet would rise in the right position. From the usual Valley viewpoint farther north the comet would have been behind the butte.

While the planning worked, the result was not quite the spectacle I had envisioned. The comet was nice, but was starting to become lost in the bright sky as it descended toward the Sun.

There were only a couple of mornings left to catch the comet at dawn before it disappeared completely into the daytime sky close to the Sun.

October 1 to 11 — at Quailway Cottage, Arizona

The major block of time in my trip was booked for an astrophoto retreat at a cottage I’d rented twice before but not since late 2017. The Quailway Cottage, popular among birders, is also ideal for stargazing as it is in one of the darkest areas of the Southwest, north of Douglas, Arizona, and just across the Arizona/New Mexico border.

This captures both the glow of Zodiacal Light in the eastern dawn sky (the band of light extending up across the frame) and the dust tail of Comet Tsuchinshan-ATLAS rising from behind the Pelloncillo mountains, at dawn on October 2, 2024.

When I arrived the comet was putting in its last show in the dawn sky. In fact, on October 2 I managed to capture a dawn scene with the morning Zodiacal Light created by sunlight reflecting off cometary dust in the inner solar system, and just the tail of the comet rising before the bright comet head appeared.

Comet C/2023 A3, Tsuchinshan-ATLAS, is rising in the dawn twilight over the Pelloncillo Mountains in New Mexico, on October 2, 2024.

An image taken a little later showed the entire comet, now sporting a more impressive tail. It was blossoming into a fine comet indeed. But we were about to lose sight of it for more than a week.

Arizona Deep-Sky Imaging

While at Quailway I had clear skies every night. And so, as planned, I went to town shooting all kinds of “deep-sky” objects and fields with two astrophoto rigs I had brought with me: a longer-focal length 120mm refractor for small targets, and a short-focal length refractor for wide fields in the Milky Way. I had reviewed both new telescopes in recent months.

The Askar APO120 on a veteran Astro-Physics AP400 mount.

I concentrated on shooting targets low in the south that are impossible to get from home in Canada, and that I’ve missed shooting, or have not shot well, during my visits to Australia. See my blog here about my latest trek Down Under.

The two brightest Fornax cluster members are the elliptical galaxy NGC 1399 at upper left, paired with smaller NGC 1404, and the galaxy NGC 1365 at lower right, considered one of the best barred spirals in the sky.

Here’s an example, above, with the larger Askar 120APO: a field of galaxies in the constellation of Fornax that rivals the better-known Markarian’s Chain of galaxies in Coma Berenices in the northern spring sky.

This frames the spectacular region of the Milky Way near the direction of the galactic centre in Sagittarius.

And here’s a field (above) with the small Founder Optics Draco 62mm scope, framing the rich Sagittarius Starcloud punctuated with the small dark Ink Spot Nebula, all below the bright Lagoon and Trifid Nebulas.

This panorama extends for about 240º along the northern half of the Milky Way, from Orion at left, to Sagittarius at right, and centered on the Galactic Equator.

In autumn the Milky Way is up all night. So I used a simple star tracker, the MSM Nomad reviewed here on my blog, and a 28-70mm lens at 35mm to shoot a panorama from dusk to dawn along the Milky Way — from the summer stars of Sagittarius and Cygnus (at right, above), through the autumn constellations overhead in Cassiopeia and Perseus (at centre), and down into the pre-dawn sky with the winter stars in and around Orion (at left).

A Bonus Aurora from Arizona

I was just north of the Mexican border, at a latitude 32° North, more than 20° farther south than at home in Alberta. But what should appear in my sky but … aurora!

A selfie of me observing the great red aurora of October 10, 2024, from southern Arizona.

On October 9, and then again more so on October 10, a great solar storm brought Northern Lights down to me. And indeed across all of Canada and the U.S. The result for me was a red glow to the north — the tops of distant auroral curtains I would have seen filling my sky at home.

A time-lapse of an Arizona aurora, using a 15mm wide-angle lens shooting nearly 400 forty-second exposures. View it in-line here. Enlarge to a full screen view. There is no sound.

Above is a time-lapse video of the aurora that night, from a camera aimed due north for four hours. The red curtains come and go through the night.

This is a 360° panorama covering the entire sky and extending up to the zenith at centre, capturing a rare SAR arc across the Arizona sky in the pre-dawn hours of October 11, 2024.

The remarkable feature that night, October 10/11, was not the aurora, but what is called a SAR (Stable Auroral Red) arc that persisted all night. It appeared as a diffuse red band across the sky, created by heat energy leaking into the upper atmosphere during the solar storm. SAR arcs can accompany an aurora but are not auroras themselves.

This panorama takes in a rare confluence of skyglows in a colourful dawn sky.

By dawn the next morning, now October 11, the tall Zodiacal Light was prominent alongside the magenta SAR arc to the north (left) and the winter Milky Way to the south (right). There’s even a short pillar of light that might be an aurora fragment, or the tail of the comet!

The Comet Returns

However, toward the end of my 11-night marathon of deep-sky imaging, the bright head of the comet was to be rising into the evening sky for Part 2 of its apparition. Below is a shot from the evening of October 11, my last at Quailway. Yes, there it was, just above the Chiricahua Mountains. But it was a blip, barely visible in binoculars and to the camera. I had hoped for more.

This is Comet Tsuchinshan-ATLAS (C/2023 A3) at far right, barely visible emerging into the evening sky and low in the twilight, on October 11, 2024. This view includes Venus at left. Venus was obvious; the comet was not!

With the Moon now waxing into the evening sky, my plan was to head back north, stopping at scenic spots on the trip home, to catch the comet over moonlit landscapes to the west in the dusk sky.

My first two nights, October 12 and 13, at the VLA Radio Observatory near Socorro, New Mexico, then farther north near Canyon de Chelly, Arizona, were both beset by clouds to the west. From images posted on-line, I knew the comet was improving. But it was eluding me.

October 14 & 15 — at Arches National Park, Utah

The next stop was Arches National Park in Utah, which I last visited in April 2015. The first night’s forecast for October 14 also looked to be cloudy. But October 15 was supposed to be clear. So I extended my stay by an extra night, thinking that might be my only chance.

As it turned out October 14 was fabulous (below). The comet was easily visible to the unaided eye as a classic comet in the west. I pointed it out to folks walking by at the Windows Arches area. And I could hear other people commenting on it. At last a comet! One that anyone could see — though it helped to be at a clear sky site like Arches.

Comet Tsuchinshan-ATLAS at its finest in the evening sky, two days after its closest approach to Earth, and with it sporting a 10º- to 15º-long dust tail, and a narrow anti-tail pointed toward the horizon.

By then the Moon was well advanced in age to a bright gibbous phase, so the sky was by no means dark. It was deep blue in photos.

Still the comet showed up brilliantly; it had blossomed a lot in a couple of nights. Above, I framed it beside moonlit Turret Arch.

Below is a scene from the next night, October 15, my “back-up” night. The comet was certainly performing well after all. Even in the moonlight. In binoculars the tail stretched for the same length as the camera recorded it, some 15°.

This is a telephoto close-up Comet Tsuchinshan-ATLAS over the red rocks of Arches National Park, Utah, on a superb moonlit night, October 15, 2024.

Indeed, that was my last view of the comet for a while, as clouds prevented any more shooting on the rest of my journey north through Idaho and Montana. I even hit a snowstorm in southern Montana.

Late October — Back at Home in Alberta

But the comet was not done yet! Through October, while it receded from us in distance, it climbed higher into our sky, placing it into a dark sky with the Moon now out of the way.

This is Comet Tsuchinshan-ATLAS in a wide-angle nightscape scene over the Badlands of Dinosaur Provincial Park, Alberta, on October 23, 2024.

On October 23, a short trip out to Dinosaur Provincial Park east of home allowed me to shoot the comet over the Alberta Badlands landscape, beside the setting summer Milky Way.

This is a telephoto lens framing of Comet Tsuchinshan-ATLAS in Ophiuchus on the night of October 30, 2024 near several large star clusters. The field of view is 15º by 10º so the tail extends for about 6º to 8º.

By a week later, on October 30, the comet had diminished in size and brightness, but still looked like a classic comet, here framed in a telephoto close-up as it passed near some bright star clusters. This was from my front yard. The chase was over.

Clouds and a trip to Norway starting November 4 prevented more opportunities to shoot the comet. (My travel schedule also kept me from writing this blog until now!)

It had been a good chase over a month, yielding images I was happy with. The photos from Utah and Arizona I could not have taken at home, even if the skies had been clear during the comet’s prime-time. (They weren’t!) And it was great to finally get back to my favourite haunts in southern Arizona and New Mexico after an absence of seven years.

In all, Comet Tsuchinshan-ATLAS provided a fine finale to what has been a superb year of stargazing events and celestial sights.

— Alan, December 9, 2024 — AmazingSky.com