Urban Orion


Urban Nightscape – Orion over Calgary

On a very clear night, Orion shines over the skyline of Calgary.

As I live in the country, it’s not often I shoot the stars from urban sites, and certainly not from downtown Calgary. But the combination of a clear night and a speaking commitment in Calgary provided a chance to see what was possible under ideal conditions.

The lead image is real – I did not paste an image of the sky taken at some other time or place over the skyline image.

However, the sky image is a longer exposure (10 seconds) than the ground (3 seconds) in order to bring out the stars better, while keeping the city lights under control with no overexposure. So it is sort of a high dynamic range blend.

The other factor that helped reveal stars as faint as shown here (fainter than what the naked eye can see) is the use of a light pollution reduction filter (a NISI Natural Night filter) to penetrate the yellow sky glow and provide a more pleasing colour to the sky.

Earlier in the night, during twilight when urban light pollution is not so much of an issue, I shot the waxing crescent Moon setting over the skyline.

Crresent Moon over Calgary

This is a panorama image made from high dynamic range blends of various exposures, to again accommodate the large range in brightness in the scene. But I did not use the NISI filter here.

These images demonstrate how you can get fine astronomy images even from urban sites, with planning and timing.

To that end, I used my favourite app, The Photographer’s Ephemeris, to determine where the sky elements would be as seen from a couple of viewpoints over the city that I’ve used in the past.

The blue spheres in the left image of TPE in its Night mode represent the Milky Way. That chart also shows the direction toward Orion over the city core.

The right image of TPE in its Day mode shows the position of the Moon at 6 pm that evening, again showing it to the left of the urban core.

Other apps are capable of providing the same information, but I like TPE for its ease of use.

Clear skies!

— Alan, January 20, 2018 / © 2018 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

 

Winter Stars over the Badlands


Orion Rising Star Trails at Dinosaur Park

The clouds cleared to present a magical night under the Moon in the Badlands of southern Alberta.

At last, a break in the incessant clouds of November, to provide me with a fine night of photography at one of my favourite places, Dinosaur Provincial Park, declared a U.N. World Heritage Site for its deposits of late Cretaceous fossils.

I go there to shoot the night sky over the iconic hoodoos and bentonite clay hills.

November is a great time to capture the equally iconic constellation of Orion rising in the east in the early evening. The scene is even better if there’s a Moon to light the landscape.

November 27 presented the ideal combination of circumstances: clear skies (at least later at night), and a first quarter Moon to provide enough light without washing out the sky too much and positioned to the south and west away from the target of interest – Orion and the winter sky rising in the east.

Below is a slide show of some of the still images I shot, all with the Canon 6D MkII camera and fine Rokinon 14mm f/2.5 lens, used wide open. Most are 15-second exposures, untracked.

This slideshow requires JavaScript.

I kept another camera, the Nikon D750 and Sigma 24mm Art lens, busy all night shooting 1200 frames for a time-lapse of Orion rising, with clouds drifting through, then clearing.

Below is the resulting video, presented in two versions: first with the original but processed frames assembled into a movie, followed by a version where the movie frames show accumulating star trails to provide a better sense of sky motion.

To create the frames for this version I used the Photoshop actions Advanced Stacker Plus, from StarCircleAcademy. They can stack images then export a new set of frames each with the tapering trails, which you then assemble into a movie. I also used it to produce the lead image at top.

The techniques and steps are all outlined in my eBook, highlighted at top right.

The HD movie is just embedded here, and is not published on Vimeo or YouTube. Expand to fill your screen.

To help plan the shoot I used the astronomy software Starry Night, and the photo planning software The Photographer’s Ephemeris, or TPE. With it, you can place yourself at the exact spot to see how the Sun, Moon and stars will appear in sightlines to the horizon.

Here’s the example screen shot. The spheres across the sky represent the Milky Way.

IMG_3517

Look east to see Orion now in the evening sky. Later this winter, Orion will be due south at nightfall.

Clear skies!

— Alan, November 29, 2017 / © 2017 AmazingSky.com

 

Hello, Austral Autumn Sky


Southern Autumn Sky Panorama (Spherical)

The sky looks very different from down under. This is the entire sky of early evening as autumn begins in the southern hemisphere.

My last post showed Orion and the winter sky disappearing into the west, from home in Alberta.

This post shows that same area of sky (here at top) also setting into the west. But that’s the only area of sky familiar to northern hemisphere stargazers.

Everything below Orion and Sirius is new celestial territory for the northern astronomer. Welcome to the fabulous southern hemisphere sky.

And to the autumn sky – From home it is spring. From here in the southern hemisphere summer is giving way to cool nights of autumn.

Straight up, at centre, is the faint Milky Way area containing the constellations of Puppis and Vela, formerly in the constellation of Argo Navis.

Below, the Milky Way brightens in Carina and Crux, the Southern Cross, where dark lanes divide the Milky Way.

At right, the two patches of light are the Large and Small Magellanic Clouds, satellite galaxies of our Milky Way.

The bright object at left is Jupiter rising over the Tasman Sea.

Southern Autumn Sky Panorama (with Labels)

I shot this 360° panorama on March 31, 2017 from Cape Conran on the Gippsland Coast of Victoria, Australia, at a latitude of 37° South.

I’ve turned the panorama so Orion appears as we’re used to seeing him, head up and feet below. But here in the southern hemisphere the image below despicts what he looks like, as he dives headfirst into the west in the evening twilight.

Orion and Waxing Moon Setting at Cape Conran

The bright object here is the waxing crescent Moon, here in Taurus. Taurus is below Orion, while Sirius (the bright star at top) and the stars of Canis Major are above Orion.

Orion, the Milky Way and Waxing Moon at Cape Conran

This view above takes in more of Canis Major. Note the Pleiades to the right of the Moon.

Visiting the southern hemisphere is a wonderful experience for any stargazer. The sky is disorienting, but filled with new wonders to see and old sights turned quite literally on their heads!

— Alan, April 4, 2017 / © 2017 Alan Dyer / AmazingSky.com

 

Farewell Winter Sky


Panorama of the Winter Sky in March

As we celebrate the official arrival of spring in the Northern Hemisphere, we bid adieu to the stars of winter.

This was the scene last night from my backyard, of Orion and the surrounding constellations of the winter sky setting into the southwest in the early evening. Each night they will set sooner and sooner, even as the nights continue to grow shorter and the Sun sets later.

By late April Orion will be gone from our Northern Hemisphere sky — he hangs around until well into May for sites south of the equator.

Panorama of the Winter Sky in March (with Labels)
A horizon-to-zenith panorama of the winter consellations on a March evening as they set into the southwest. Taken from home March 19, 2017. This is a panorama of 5 panels, each with the 20mm Sigma Art lens at f/2, and Nikon D750 at ISO 3200, for 25 seconds each. Stitched with Adobe Camera Raw.

In this version I’ve labeled the main characters in this winter hunting scene – including some of the deep-sky “Messier”  objects like M45, the Pleiades; M44, the Beehive star cluster; and M42, the Orion Nebula.

At the same time this year, we also say goodbye to Venus which has shone so brightly these last few months as an evening star. By this weekend, it will be lost from sight as it passes between Earth and the Sun.

Mercury Rising and Venus Descending (with Labels)
Mercury (left) and Venus (right and bright) shinng low in the evening twilight, on March 19, 2017. Mercury was then 2 weeks before greatest elongation while Venus was a week before inferior conjunction. So Mercury was rising into the evening sky while Venus was rapidly descending. This is a 7-image HDR stack of exposures from 2.5 seconds to 1.6-second at ISO 200 with the Canon 6D and with the Sigma 50mm lens at f/4.

Meanwhile, Mercury is rising into view in the evening twilight, in its best evening showing of the year from northern latitudes. The view below is also from March 19, with Mercury to the left of brighter Venus.

Over the next two weeks, look low in the west for a bright star amid the twilight. Mercury appears farthest from the Sun on April 1, the date of its “greatest elongation.”

Having Mercury in our evening sky is a sure sign of spring.

Leo and the Spring Stars Rising
Leo rising in the east along with the northern hemisphere spring stars. Numerous satellite trails are visible. I didn’t clone them out. This is a vertical panorama of 4 frames, with the 20mm Sigma Art lens at f/2 and 25 seconds at ISO 3200 with the Nikon D750. Stitched with PTGui using Transverse Equirectangular projection.

Another sign of spring is Leo the lion.

While Orion sets in the west, the stars of spring are rising in the east. The panorama above depicts the scene in the eastern sky these nights, as Leo rises below the Big Dipper.

The Big Dipper is at upper left, with its handle pointing down to Arcturus at bottom left. The Bowl of the Dipper points down to the right to Regulus and the stars of Leo.

Above Leo is the star cluster M44, the Beehive, in Cancer. Below Leo at centre is the star cluster Mel 111, the Coma Berenices star cluster near the North Galactic Pole.

Happy Equinox! 

— Alan, March 20, 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