Dawn Sky Delights


Aldebaran About to be Occulted by the Moon

It was one of those mornings when the sky was full of wonder.

After days and nights of smoke from unfortunate fires burning not far away, including in my favourite national park of Waterton Lakes, the sky cleared enough this morning, September 12, to reveal some fine sights.

At 6 a.m. the waning gibbous Moon passed in front of the star Aldebaran in Taurus. It is performing many such occultations of Aldebaran this year, but most aren’t well seen from any one location. This one was ideal, right from my backyard.

The lead image is a “high dynamic range” stack of several exposures showing the waning Moon and star set in some high haze adding the sky colours.

The star winked out behind the Moon’s bright limb as the Moon advanced from right to left (west to east) against the background sky.

Occultation of Aldebaran
Aldebaran nearing the limb of the Moon.
This shows a composite sequence, with images of the star taken every four minutes blended with a single image of the Moon. While it looks like the star is moving, it is really the Moon that is edging closer to Aldebaran.

The star reappeared from behind the dark limb of the Moon, but five minutes after sunrise, with the Moon in a bright blue sky. Still, the star stood out nicely in binoculars and in the telescope for this view.

Aldebaran Near the Moon in Day Sky
Aldebaran off the dark limb of the Moon.
Aldebaran is the point of light at right, just off the invisible edge of the Moon.

I shot stills and video, and compiled them into this short video.

Enlarge it to full screen to view it properly.

Meanwhile, over to the east the twilight sky was awash in planets.

Rocky Planets at Dawn with Labels (Sept. 12, 2017)
The line of dawn planets, with labels.
All the three inner terrestrial worlds were there: Venus, at top, Mercury below Regulus, and Mars lowest of the trio. Of course, a fourth terrestrial world is in the photo, too – Earth!

Mercury was at its greatest western elongation this morning, placing it as far from the Sun and as high in the sky as it gets, with this autumn appearance the best of 2017 for a morning showing for Mercury. Even so, you can see how Mercury is always low and easy to miss. However, this morning it was obvious to the naked eye.

Mars and Mercury will be in close conjunction at dawn on the morning of September 16.

Rocky Planets at Dawn (Sept. 12, 2017)

It was a fine morning to be up early and enjoy the solar system show.

— Alan, September 12, 2017 / © 2017 Alan Dyer / amazingsky.com

 

The Moons of Lost Sleep


Waning Moon in the Morning Series (with Labels)

These are the Moons only insomniacs and night shift workers get to see. These are the waning Moons of morning.

For eight mornings I’ve been up at 4 a.m. each day to catch the early Moon and collect a series of images of its waning phases.

The result is above, a series that runs from right to left in time, from the 19-day-old waning gibbous Moon, to the 26-day-old thin crescent Moon.

I ordered them that way in the composite to reflect the direction the Moon moves across the sky. As it orbits Earth and wanes, the Moon moves from west to east, or right to left, in the sky from morning to morning, at least in the northern hemisphere.

A run of clear nights and mornings made the series possible. From Alberta, as dry as it is, too many cloudy nights make a consistent Moon phase series a challenge at best.

As it was I had to contend with smoke from forest fires in B.C. which reddened the Moon on the last few mornings, a tint I had to correct for the composite above. But here below, is what the Moon really looked like one morning.

Smoky Waning Crescent Moon
The smoky orange Moon of July 17.

The last two Moons, at 25 and 26 days old (i.e. the number of days since the previous New Moon phase) exhibited the phenomenon known as Earthshine. You can see the night side of the Moon glowing gently with sunlight reflected first off the Earth.

Waning Moon and Earthshine (July 20, 2017)
Earthshine on the 25-day old Moon on July 20 at dawn.

Below, this was the Moon this morning, July 21, with it very low in the east amid the twilight sky.

Waning 26-Day Moon with Earthshine
Earthshine on the thin 26-day old Moon on July 21 at dawn.

This final morning was exceptional. The smoke had cleared off, and when I got up at 4 a.m. (reluctantly!) for the last shoot I was greeted with the best display of noctilucent clouds I had seen in many years. They covered the northeast and eastern skies in a rare “grand display.”

Noctilucent Clouds at Dawn with the Moon and Venus
Noctilucent clouds with the Moon and Venus in the dawn sky, from southern Alberta, July 21, 2017.

The thin crescent Moon is just rising at right, with Venus bright as a “morning star” at far right. This was a sky certainly worth losing sleep over.

— Alan, July 21, 2017 / © 2017 Alan Dyer / amazingsky.com

 

Rising of the “Strawberry” Moon


The Rising Strawberry Moon of June 9, 2017 (Composite)

The Full Moon of June rose into a twilight sky over a prairie pond. 

On June 9, the clouds cleared to present an ideal sky for capturing the rising of the so-called “Strawberry Moon,” the popular name for the Full Moon of June.

The lead image is a composite of 15 frames, taken at roughly 2.5-minute intervals and stacked in Photoshop with the Lighten blend mode.

The image below is a single frame.

The Rising Strawberry Moon of June 9, 2017
The rising Full Moon of June, dubbed the “Strawberry Moon” in the media, as seen rising over a prairie pond in southern Alberta, on June 9, 2017. This is a single exposure stack, from a time-lapse sequence of 1100 frames, with images taken at two second intervals. Shot with the Canon 6D and 200mm lens.
I set up beside a small local prairie pond, to shoot the moonrise over the water. Ducks enjoyed the view and a muskrat swam by at one point.

I shot over 1100 frames, at two-second intervals to create a time-lapse of the rising Moon, as it brightened and turned from yellow-orange (not quite strawberry pink) to a bright white.

Here’s the time-lapse vignette.

Click on HD for the best view.

While the Harvest Moon gets lots of PR, as this sequence shows any Full Moon can provide a fine sight, and look yellow, due to absorption of the blue wavelengths by the atmosphere as the Moon rises, or as it sets.

However, the timing can vary from Full Moon to Full Moon. This one was ideal, with it rising right at sunset. If the Moon comes up too late, the sky might have already darkened, producing too great a difference in brightness between the Moon and background sky to be photogenic.

But what of these Moon names? How authentic are they? 

Who called this the Strawberry Moon? Native Americans? No. Or at best only one or two nations. 

Check the site at Western Washington University at http://www.wwu.edu/depts/skywise/indianmoons.html and you’ll see there were an enormous number of names in use, assuming even this listing is authentic. 

The names like “Strawberry Moon” that are popularized in the media today come from the American Farmers Almanac, and everyone – science writers and bloggers – ends up copying and pasting the same wrong, or at best misleading, information from the Almanac. 

Search for “Strawberry Moon” or “Moon names” and you’ll find the same explanation repeated verbatim and unquestioned by many writers. Alas, the Almanac is not an authoritative source – after all, they were the source of a misleading definition of Blue Moon decades ago. 

Yes, people around the world may have long had names for months and moons, but they were not necessarily the ones that make the rounds of news sites and blogs today. Most are a modern media concoction. A few years ago, pre-internet, no one knew about nor used these names. 
— Alan, June 10, 2017 / © 2017 Alan Dyer / www.amazingsky.com

The Austral Moon of Evening


Waxing Moon in Evening Twilight Colours

From the southern hemisphere the Moon appears “upside-down” and higher each night in the northern sky as it waxes from crescent to Full.

These are scenes from the last week as the Moon rose higher into the evening sky as seen from Australia.

A northerner familiar with the sky would look at these and think these are images of the waning Moon at dawn in the eastern sky.

Waxing Crescent Moon at Cape Conran
The “upside-down” waxing crescent Moon in the evening sky from Victoria, Australia, at Cape Conran, West Cape area, on the Gippsland Coast, at latitude 37° South. Earthshine lights the dark side of the Moon. This was March 31, 2017. The Moon lights a glitter path on the water. This is a single 1.3-second exposure at f/2 with the 85mm Rokinon lens, and Canon 5D MkII at ISO 400.

But no, these are of the waxing Moon (the phases from New to Full) with the Moon in the evening sky.

From the southern hemisphere the ecliptic – the path of the planets – and the path of the Moon arcs across the northern sky. So as the Moon waxes from New to Full phase it appears to the right of the Sun, which still sets in the west. The world still spins the same way down under!

So the Moon appears upside down and with the crescent phase the “wrong” way for us northerners.

Panorama of the Waxing Moon at Sunset at Welshpool Harbour
A 240° panorama from 16 segments.

This panorama taken April 4 sweeps from northwest to southeast, but looks north at centre, to capture the scene at sunset of the waxing 8-day gibbous Moon in the northern sky as seen from the southern hemisphere.

The angle between the Sun and Moon is just over 90°, shown here by the angle between the right-angle arms of the wharf, pointed to the west at left, to the north at centre, and to the east at right.

The Sun has set just north of west, while the Moon sits 13° east of due north. The Earth’s shadow rises as the blue arc at far right to the east opposite the Sun.

Philip Island Sunset and Waxing Moon Panorama
A 240° panorama from 15 segments.

The next night, April 5, I shot this panorama from Philip Island south of Melbourne. Again, it shows the waxing gibbous Moon in the north far to the right of the setting Sun in the west (at left).

Getting used to the motion of the Sun and Moon across the northern sky, and the Moon appearing on the other side of the Sun than we are used to, is one of the challenges of getting to know the southern sky.

Things just don’t appear where nor move as you expect them to. But that’s one of the great delights of southern star gazing.

— Alan, April 8, 2017 / © 2017 Alan Dyer / www.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 

 

End of Year Skies


New Moon for a New Year

The crescent Moon rises into the western evening sky as 2016 ends, while Venus shines bright, and Orion rises into the east.

Getting clear skies is a rare treat of late, but these are images from two such nights this week. On December 30, the thin waxing Moon appeared in the colourful twilight of a winter night. Despite the clouds and the Moon’s low altitude, the dark side of the Moon is plainly visible illuminated by Earthshine.

Venus in Twilight over Pioneer Grain Elevators

Venus is now brilliant as an evening star in the southwest. Here is it over the old wood grain elevators at Mossleigh, Alberta, some of the few of these landmarks left standing on the prairies.

Fainter Mars shines above Venus and over the month of January, Venus will climb up to meet Mars by month’s end for a fine conjunction with the crescent Moon as well. Watch through January as Venus and Mars converge.

Orion and Pioneer Grain Elevators

As the planets set into the southwest, Orion the Hunter rises into the east. Here it is over the Mossleigh elevators, illuminated by local lights.

Enjoy the winter skies as clouds permit!

Clear skies and Happy New Year!

— Alan, December 31, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

Moon and Star Conjunction


Moon and Aldebaran (July 29, 2016)

The waning Moon shone near the bright star Aldebaran in the dawn sky.

This was a beautiful sight this morning, before dawn on July 29. The crescent Moon, its night side illuminated by Earthshine, shone just below the brightest star in Taurus.

We are currently in 3-year period when the Moon’s path is taking it near or in front of Aldebaran every month. However, most of these occultations or conjunctions are not well-timed for any particular location. And many involve the too-brilliant gibbous or full Moon.

But this morning the timing and Moon phase were perfect. From my longitude on Earth in Alberta, the Moon passed closest to the star just before the sky was getting too bright with dawn. Having them set against the deep blue twilight was perfect.

From farther east the Moon would not have appeared as close to Aldebaran as this before sunrise. From farther west the Moon and star would have appeared much lower in the sky at closest approach.

Moon & Aldebaran Screen

TECHNICAL:

For this image I shot 6 exposures, from 2 seconds for the Earthshine, twilight sky colour and stars, to 1/125th second for the bright crescent. I then stacked, aligned, and blended them together using luminosity masks – masks that hide or reveal parts of the image based on the brightness of the scene. You can see them in the Photoshop screen shot – Click on the image to enlarge it.

How do you create these masks?

• Turn off all the layers except the one you want to create a mask for.

• Go to Channels and Command/Control Click on the RGB Channel.

• That automatically selects all the highlights.

• Go back to the image layer and then hit the Add Mask button down at the bottom of the Layers panel (the rectangle with the black dot in it).

• Done. Repeat that for each image layer.

More traditional high dynamic range or “HDR” stacking left odd colour fringing artifacts and double images on the slowly moving Moon, despite applying what is called “de-ghosting” and despite using a mount tracking at the lunar rate. I tried merging the images with HDR, but it didn’t work.

A nifty Photoshop action from the Astronomy Tools set by Noel Carboni added the diffraction spikes.

I shot all images with the 130mm Astro-Physics refractor at f/6 and the Canon 60Da camera at ISO 400.

— Alan, July 29, 2016 / © 2016 Alan Dyer / www.amazingsky.com