Dinosaur Park in the Dark


Winter Sky Setting in Twilight at Dinosaur Park

There’s a slogan used in the U.S. National Parks that “half the Park is after dark.” It is certainly true at Dinosaur Provincial Park in Alberta. 

Last Friday night, March 29, I spent the evening at one of my favourite nightscape sites, Dinosaur Provincial Park, about an hour’s drive east of my home. It was one of those magical nights – clear, mild, dry, and no mosquitoes! Yet!

I wanted to shoot Orion and the photogenic winter sky setting into the evening twilight over the Badlands landscape. This was the last moonless weekend to do so.

I shot some individual images (such as above) and also multi-panel panoramas, created by shooting a series of overlapping images at equal spacings, then stitching them later at the computer.

Winter Sky Setting at Dinosaur Park Panorama
This is a 240° panorama stitched from 17 segments, all with the 24mm Sigma Art lens and Nikon D750 in portrait orientation, each segment 20 seconds at f/1.4 and ISO 3200. Stitched with Adobe Camera Raw.

There’s a narrow window of time between twilight and full darkness when the Milky Way shows up well but the western sky still has a lingering blue glow. This window occurs after the normal “blue hour” favoured by photographers.

The panorama above shows the arch of the winter Milky Way but also the towering band of the Zodiacal Light rising out of the twilight and distant yellow glow of Calgary. Zodiacal Light is sunlight scattering off meteoric and cometary dust orbiting in the inner solar system, so this is a phenomenon in space not in our atmosphere. However, the narrow streak is an aircraft contrail.

Spring Sky Panorama at Dinosaur Park
A 360° panorama of the spring sky over the Badlands of Dinosaur Provincial Park, Alberta. This is a panorama of 12 segments taken with the 14mm Sigma Art lens and Nikon D750 in portrait orientation, all for 30 seconds at f/2.8 and ISO 4000. Taken at 30° spacings. Stitched with PTGui.

Later that night, when the sky was fully dark I shot this complete panorama showing not only the Milky Way and Zodiacal Light to the west, but also the faint arc of the Zodiacal Band continuing on from the pyramid-shaped Zodiacal Light over into the east, where it brightens into the subtle glow of Gegenschein. This is caused by sunlight reflecting off interplanetary dust particles in the direction opposite the Sun.

Both the Band and Gegenschein were visible to the naked eye, but only if you knew what to look for, and have a very dark sky.

The Winter Stars and Zodiacal Light at Dinosaur Park
This is a panorama stitched from 3 segments, all with the 24mm Sigma Art lens and Nikon D750, for 20 seconds at f/2.2 and ISO 4000. Stitched with Adobe Camera Raw.

A closeup shows the Zodiacal Light in the west as the subtle blue glow tapering toward the top as it meets the Milky Way.

It takes a dark site to see these subtle glows. Dinosaur Park is not an official Dark Sky Preserve but certainly deserves to be. Now if we could only get Calgary, Brooks and Bassano to turn down and shield their lights!

Spring Sky RIsing at Dinosaur Park Panorama
A 180° panorama of the spring sky and constellations rising in the east over the Badlands of Dinosaur Provincial Park, Alberta on March 29, 2019. This is a stitch of 6 segments, each with the 14mm Sigma Art lens and Nikon D750 in portrait mode, each 30 seconds at f/2.8 and ISO 4000. Stitched with PTGui.

A closeup facing the other way, to the east, shows the area of sky opposite the Milky Way, in the spring sky. The familiar Big Dipper, now high our spring sky, is at top with its handle pointing down to Arcturus and Spica (just rising above the horizon) – remember to “arc to Arcturus, and speed on to Spica.”

Leo is at right of centre, flanked by the Beehive and Coma Berenices star clusters.

Polaris is at left — however, the distortion introduced by the panorama stitching at high altitudes stretches out the sky at the top of the frame, so the Dipper’s Pointer stars do not point in a straight line to Polaris.

The faint Zodiacal Band is visible at right, brightening toward the horizon in the Gegenschein.

I shoot images like these for use as illustrations in future eBook projects about stargazing and the wonders of the night sky. Several are in the works!

Clear skies!

— Alan, April 1, 2019 / © 2019 Alan Dyer / AmazingSky.com

 

Chasing Meteors


Geminid Meteor Radiant in Gemini

Meteors were raining down the sky on the peak night of the Geminid meteor shower.

Back in August, when I wrote my column for the November-December issue of our Canadian magazine SkyNews, I noticed how good the circumstances were this year for the annual Geminid meteor shower. Normally one of the best showers of the year, if not the best, the Geminids were really going to perform in 2017.

The Moon was near new so its light would not interfere. For western North America, the peak of the shower was also timed for midnight on the night of December 13/14, just when the radiant of the shower was high in the sky.

Raining Geminid Meteors
The Geminids rain down the sky from the radiant in Gemini high overhead on peak night.

So in August when I saw the favourable combination of circumstances, I decided a meteor chase was in order. While the shower would be visible from home, Geminid peak night in December is often bitterly cold or cloudy at home in Alberta.

So I planned a trek to Arizona, for the shower and the winter sky.

While skies at home proved decent after all, it was still a chase worth making, with the shower visible under the perfectly clear and dry skies of southeast Arizona.

My chosen site was the Quailway Cottage near the Arizona Sky Village, the chosen dark sky site for many amateur astronomers, and at the foot of the Chiricahua Mountains. Skies are dark!

Sky Dust - Interplanetary and Interstellar
The Zodiacal Light (left) and Milky Way over the Chiricahuas.

The Zodiacal Light was brilliant in the southwest sky for several hours after sunset. A tough sighting at this time of year from most sites, this glow was obvious in the Arizona sky. It is sunlight reflecting off cometary dust particles in the inner solar system.

Geminid Meteor Shower in the Winter Milky Way
Geminids streaking from Gemini as the winter sky rises.

On the peak night, the visual impression was of meteors appearing at a rate of at least one a minute, if not more frequently.

Geminid Meteor Radiant in Gemini
A tracked composite looking up toward Orion and Gemini.

The images here are all composites of dozens of exposures taken over 2 to 5 hours, stacking many meteors on one frame. So they do provide an exaggerated record of the shower. Meteors weren’t filling the sky! But you certainly did not have to wait long for one to appear, making this one of the best meteor showers in many years.

Geminid Meteors over the Chiricahuas
Geminids falling over the Chiricahuas as Orion sets at the end of the peak night.

Most of the Geminids were of average brightness. I didn’t see, nor did the camera catch many very bright “bolides,” the really brilliant meteors that light up the ground.

Bright Geminid Meteor Descending
A bright Geminid pierces Ursa Major.

Nevertheless, this was a night to remember, and a fine way to end what has been a superlative year of stargazing, with a total solar eclipse, great auroras, and for me, a wonderful stay under southern skies on an April trip to Australia.

All the best of the season to you and your family and friends. Clear skies!

Here’s to 2018, which begins with a total eclipse of the Moon on January 31.

— Alan, December 23, 2017 / © 2017 Alan Dyer / AmazingSky.com

 

The Ghostly Glow of Gegenschein


Northern Spring Sky Panorama

It takes a dark spring night to see it well, but now lurking near Jupiter is a ghostly sky glow called Gegenschein. 

This diffuse glow lies directly opposite the Sun. It is caused by sunlight reflecting off interplanetary dust particles in the outer solar system. They reflect light more effectively at the anti-Sun point where each dust particle is fully lit by the Sun.

Like the Sun, the Gegenschein moves around the sky along the ecliptic, moving about a degree from west to east from night to night. March and April provide good nights for seeing the Gegenschein as it then lies in an area of sky far from the Milky Way.

Even so, it is very subtle to the unaided eye. Look south at about 1 a.m. local daylight time.

However, this year, in early April the Gegenschein will be more difficult as it will then lie right on top of Jupiter, as that planet reaches its point opposite the Sun on April 7. Jupiter will then be superimposed on the Gegenschein.

The main image at top is a 7-image vertical panorama of the spring sky, from Corvus and Virgo above the horizon, up past Leo, into Ursa Major and the Big Dipper overhead. Spica lies below bright Jupiter, Arcturus in Böotes is at left, while Regulus in Leo is at right. The grouping of stars near centre is the Coma Berenices star cluster.

Orion over the Old Barn

Earlier in the night, I shot the sky’s other main glow – the Milky Way, as the winter portion of the Milky Way around Orion set into the southwest.

But over in the west, at the right edge of the frame, is the Zodiacal Light, caused by the same dust particles that create the Gegenschein, but that are located in the inner solar system between us and the Sun.

The Zodiacal Light is better depicted in images in my previous post from Dinosaur Park

We bid adieu to the winter Milky Way now. As it departs we are left with an evening sky without the Milky Way visible at all. As seen from northern latitudes it lies along the horizon.

But later in spring, late at night, we’ll see the summer Milky Way rising, beginning its seasons of prominence until late autumn.

— Alan, March 19, 2017 / © 2017 Alan Dyer / AmazingSky.com 

 

A Starry Night in the Badlands


Winter Milky Way Arch and Zodiacal Light

In a winter of cloud, the skies cleared for a magical night in the Alberta Badlands.

Two weeks ago, on February 28, I took advantage of a rare and pristine night to head to one of my favourite spots in Dinosaur Provincial Park, to shoot nightscapes of the winter sky over the Badlands.

A spate of warm weather had melted most of the snow, so the landscape doesn’t look too wintery. But the stars definitely belong to winter in the Northern Hemisphere.

The main image above shows the winter Milky Way arching across the sky from southeast (at left) to northwest (at right). The tower of light in the west is the Zodiacal Light, caused by sunlight reflecting off dust particles in the inner solar system. It is an interplanetary, not atmospheric, effect.

Winter Sky Panorama at Dinosaur Park (Fish-Eye View)
This is a stitch of 6 segments with the 12mm Rokinon lens at f/2.8 for 30 seconds each, with the Nikon D750 at ISO 6400, mounted portrait. Stitched with PTGui.

Above, this 360° version of the scene records the entire sky, with the winter Milky Way from horizon to horizon. With a little averted imagination you can also trace the Zodiacal Light from west (right) over to the eastern sky (left), where it brightens in the diffuse glow of the Gegenschein, where dust opposite the Sun in the outer solar system reflects light back to us.

Winter Sky Panorama at Dinosaur Park (with Labels)
This is a stitch of 6 segments taken with the 12mm full-fame fish-eye Rokinon lens at f/2.8, all 30-second exposures with the Nikon D750 at ISO 6400. The camera was aimed portrait with the segments at 60° spacings. Stitched with PTGui using equirectangular projection with the zeith pulled down slightly.

A rectangular version of the panorama wraps the sky around from east (left), with Leo rising, to northeast (right), with the Big Dipper standing on its handle. I’ve added the labels in Photoshop of course.

Winter Stars over Dinosaur Park
This is a stack of 8 x 30-second exposures for the ground, mean combined to smooth noise, plus one 30-second exposure for the sky. All at f/2.2 with the Sigma 20mm Art lens and Nikon D750 at ISO 6400.

Here, in a single-frame shot, Orion is at centre, Canis Major (with Sirius) is below left, and Taurus (with Aldebaran) is at upper right. The Milky Way runs down to the south. The clusters M35, M41, M46 and M47 are visible as diffuse spots, as is the Orion Nebula, M42, below Orion’s Belt.

Evening Zodiacal Light at Dinosaur Park
The late winter evening Zodiacal Light, from at Dinosaur Provincial Park, Alberta, February 28, 2017. This is a stack of 7 x 30-second exposures for the ground, mean combined for lower noise, plus one 30-second exposure for the sky, all at f/2 with the 20mm Sigma Art lens, and Nikon D750 at ISO 6400.

This is certainly my best shot of the evening Zodiacal Light from my area in Alberta. It is obvious at this time of year on moonless nights, but requires a site with little urban skyglow to the west.

It is best visible in the evening from northern latitudes in late winter and spring.

Here, Venus is just setting above the badlands landscape. The Andromeda Galaxy is at right, the Pleiades at left. The Milky Way runs across the frame at top.

There is a common belief among nightscape photographers that the Milky Way can be seen only in summer. Not so.

What they mean is that the brightest part of the Milky Way, the galactic centre, is best seen in summer. But the Milky Way can be seen in all seasons, with the exception of spring when it is largely absent from the early evening sky, but rises late at night.

— Alan, March 14, 2017 / © 2017 Alan Dyer / AmazingSky.com 

 

Mosaic of the Autumn Constellations


Mosaic of the Northern Autumn Constellations

I present a horizon-to-zenith panorama of the pantheon of autumn constellations.

Yes, I know it’s winter, but as it gets dark each night now in early January the autumn stars are still front and centre. I took the opportunity during a run of very clear nights at home to shoot a panorama of the autumn sky.

It is a mosaic that sweeps up the sky and frames many related Greek mythological constellations:

• from the watery constellations of Aquarius, Pisces, and Cetus at the bottom near the horizon…

• to Pegasus and Aries in mid-frame…

• on up to Andromeda and Perseus at upper left…

• and finally Cassiopeia and Cepheus at the top of frame embedded in the Milky Way overhead. The Andromeda Galaxy, M31, is just above centre.

Mosaic of the Northern Autumn Constellations (with Labels)

Here, I’ve labeled the participating constellations, though only a few, such as the “square” of Pegasus and the “W” of Cassiopeia, have readily identifiable patterns.

Most of these constellations are related in Greek mythology, with Princess Andromeda being the daughter of Queen Cassiopeia and King Cepheus, who was rescued from the jaws of Cetus the Sea Monster by Perseus the Hero, who rode on Pegasus the Winged Horse in some accounts.

Zodiacal Light brightens the sky at bottom right in Aquarius, and angles across the frame to the left.


 

TECHNICAL:

I shot this from home on a very clear night January 2, 2016 with the Zodiacal Light plainly visible to the naked eye.

This is a mosaic of 5 panels, each a stack of 5 x 2 minute exposures, plus each panel having another stack of 2 x 2 minute exposures blended in, and taken through the Kenko Softon filter to add the fuzzy star glows to make the constellations stand out.

All were shot with the 24mm Canon lens at f/2.8 and Canon 5DMkII at ISO 1600. All tracked on the AP Mach One mount.

All stacking and stitching in Photoshop CC 2015. Final image size is 8500 x 5500 pixels and 3.6 gigabytes for the layered master.

– Alan, January 3, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

Morning Star, the Milky Way, and the Zodiacal Light


Venus shines brightly, and nearly at its brightest at magnitude -4.7, in the dawn sky on a very frosty morning at 5 am, on September 17, 2015, from home in southern Alberta. Venus appears amid the faint glow of the Zodiacal Light, sometimes called the “False Dawn,” stretching vertically from the dawn horizon in the east, up and to the right, and reaching the Milky Way that runs down the frame from top centre to bottom right. Orion and the winter stars shine in the Milky Way, with Sirius above the trees at lower right. The Beehive Cluster, M44, appears as the small group of stars above Venus. The Pleiades, M45, is at top right. Mars is the brightest object left of Venus, with the bright star Regulus just below it and rising in the east. The stars of the Big Dipper are at far left at the edge of the frame. The sky is beginning to brighten with the real glow of morning.  This is a stack of 4 x 2-minute exposures, tracked and mean combine stacked, for the sky and 2 x 2-minute exposures, untracked and stacked, for the ground to minimize blurring in the starlit ground. The Canon 6D was on the iOptron Sky-Tracker, shooting at ISO 1250 with the 15mm full-frame fish-eye lens at f/3.5. The stacking with a mean combine stack mode smooths noise in both sky and ground.

Venus, now at its brightest as a morning star, shines amid the subtle glow of the Zodiacal Light. 

This was the scene this morning, September 17, on a very frosty dawn at 5 a.m. from my backyard in southern Alberta.

Here, Venus shines nearly as bright as it can be, at magnitude -4.7, in the dawn sky as a brilliant “morning star.”

Venus appears amid the faint glow of the Zodiacal Light, sometimes called the “False Dawn,” stretching diagonally from the dawn horizon in the east, up and to the right, and reaching the Milky Way that runs vertically down the frame from top centre to bottom right.

Orion and the winter stars shine in the Milky Way, with Sirius above the trees at lower right.

The Beehive Cluster, M44, appears as the small group of stars above Venus. The Pleiades, M45, is at top right.

Mars is the brightest object left of Venus, with the bright star Regulus just below it and rising in the east. The stars of the Big Dipper are at far left at the edge of the frame.

The sky is beginning to brighten with the real glow of morning. It was a marvellous dawn sky delight.

Technical notes:

This is a stack of 4 x 2-minute exposures, tracked and mean-combine stacked, for the sky and 2 x 2-minute exposures, untracked and stacked, for the ground to minimize blurring in the starlit ground. The Canon 6D was on the iOptron Sky-Tracker, shooting at ISO 1250 with the 15mm full-frame fish-eye lens at f/3.5. The stacking with a mean combine stack mode smooths noise in both sky and ground.

– Alan, September 17, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

The Ghostly Glows of a Truly Dark Sky


Ghostly Glows of a Truly Dark Sky

A truly dark sky isn’t dark. It is filled with glows both subtle and spectacular.

Last night, March 10, I drove up into the heart of the Gila Wilderness in southern New Mexico, to a viewpoint at 7,900 feet in altitude. I was in search of the darkest skies in the area. I found them! There was not a light in sight.

The featured image is a 180° panorama showing:

– the Zodiacal Light (at right in the west)
– the Milky Way (up from the centre, in the south, to the upper right)
– the Zodiacal Band (faintly visible running from right to left across the frame at top)
– the Gegenschein (a brightening of the Zodiacal Band at left of frame, in the east in Leo)

The Zodiacal Light, Zodiacal Band, and the Gegenschein are all part of the same phenomenon, glows along the ecliptic path – the plane of the solar system – caused by sunlight reflecting off cometary and meteoric dust in the inner solar system.

The Gegenschein, or “counterglow,” can be seen with the naked eye as a large and diffuse brightening of the sky at the spot exactly opposite the Sun. It is caused by sunlight reflecting directly back from comet dust, the scattering effect greatest at the point opposite the Sun.

The Zodiacal Light requires reasonably dark skies to see, but the fainter Zodiacal Band and Gegenschein require very dark skies.

Now is prime season for all of them, with the Moon out of the way, and the Zodiacal Light angled up high in the western as twilight ends. In March, the Gegenschein is now located in a relatively blank area of sky in southern Leo.

The Milky Way is much more obvious. Along the northern winter Milky Way here you can see dark lanes of interstellar dust, particularly in Taurus above and to the right of Orion. Red nebulas of glowing gas also lie along the Milky Way, such as Barnard’s Loop around Orion.

– Orion is at centre, in the south, with Canis Major and the bright star Sirius below and to the left of Orion. Canopus is just setting on the southern horizon at centre. It barely clears the horizon from 32° North latitude.

– To the right of Orion is Taurus and the Pleiades star cluster at the top of the Zodiacal Light pyramid.

– Venus is the bright object in the Zodiacal Light at right, in the west, while fainter Mars is below Venus.

– At far right, in the northwest, is the Andromeda Galaxy, M31.

– Jupiter is the bright object at upper left, in the east, in the Zodiacal Band, and near the Beehive star cluster.

– The Zodiacal Light, Band and Gegenschein all lie along the ecliptic, as do Mars, Venus and Jupiter.

Glows on the horizon are from distant SIlver City, Las Cruces and El Paso. The brighter sky at right is from the last vestiges of evening twilight. Some green and red airglow bands also permeate the sky.

Standing Under the Milky Way
I shot this March 10, 2015 from the summit of Highway 15, The Trail of the Mountain Spirits, that twists and winds through the Gila Wilderness.

It was a stunning night, clear, calm, and silent. Just me under the ghostly glows of a truly dark sky.

NOTE: I first published this March 11 but had to republish this blog March 15 after WordPress deleted the original post in a software bug. Thanks WordPress! 

– Alan, March 11, 2015 / © 2015 Alan Dyer / http://www.amazingsky.newt