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

 

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

 

 

Four Planets Along the Morning Ecliptic


Four planets in the morning sky, on October 20, 2015, along the ecliptic from bottom to top:  - Mercury (close to the horizon at lower left) - Mars (dim, below Jupiter) - Jupiter (fairly bright at upper right) - Venus (brightest of the four) I shot this from home in southern Alberta. This is a composite stack of 5 exposures from 15 seconds to 1 second to contain the range of brightness from the bright horizon to the dimmer sky up higher. All with the 35mm lens and Canon 6D at ISO 800.

Four planets appear in the dawn sky outlining the morning ecliptic.

This morning, October 20, I was able to capture four planets in the morning sky, arrayed along the ecliptic.

From bottom to top they are: Mercury (just past its point of greatest elongation from the Sun), dim Mars, bright Jupiter, and very bright Venus (just 6 days away from its point of greatest elongation from the Sun). Above Venus is Regulus, in Leo.

I’ve added in the labels and the line of the ecliptic, rising steeply out of the east in the autumn dawn sky.

Of course, there is a fifth unlabelled planet in the scene, quite close in the foreground.

The image below is an unlabeled version.

Four planets in the morning sky, on October 20, 2015, along the ecliptic from bottom to top:  - Mercury (close to the horizon at lower left) - Mars (dim, below Jupiter) - Jupiter (fairly bright at upper right) - Venus (brightest of the four) I shot this from home in southern Alberta. This is a composite stack of 5 exposures from 15 seconds to 1 second to contain the range of brightness from the bright horizon to the dimmer sky up higher. All with the 35mm lens and Canon 6D at ISO 800.

Mercury will be disappearing from view very quickly now as it drops back down toward the Sun.

But over the next week the three higher planets will converge into a tight triangle just 4.5 degrees apart. We won’t see these three planets this close together in a darkened sky until November 2111.

For more information on this week’s dawn sky planet dance see my previous blog entry.

TECHNICAL:
I shot the scene from home in southern Alberta. The image is a composite stack, with manually created masks (not an HDR stack), of 5 exposures, from 15 seconds to 1 second, to contain the range of brightness from the bright horizon to the dimmer star-filled sky higher up. All are with the 35mm lens and Canon 6D at ISO 800.

— Alan, October 20, 2015 / © 2015 Alan Dyer / www.amazingsky.com

The Moon and Four Planets


The waning crescent Moon, lit by Earthshine, with four planets on the morning of October 9, 2015, with the planets from bottom left to top right: • Mercury, just above the horizon between the low cloud bands, at lower left • Jupiter, bright at centre • Mars, reddish and above Jupiter • Venus, brightest at upper right and in some thin cloud.  The bright star Regulus in Leo is above and to the left of Venus. This is a blend of four exposures: a long 4-second exposure for most of the sky and ground and shorter 2, 1, amd 1/2 second exposures for the bright twilight area and around the Moon and Venus, to prevent those areas fro being blown out. Blending is with masks, not HDR. All with the Canon 6D at ISO 400 and 50mm Sigma lens at f/2.5

The Moon appeared along with four planets in the dawn sky.

The sky was filled with planets this morning, as all four of the closest planets to the Sun appeared along the ecliptic in the morning sky. Plus there’s a fifth planet in the picture – Earth.

Here, the waning crescent Moon, lit by Earthshine, appears with four planets on the morning of October 9, 2015, with the planets from bottom left to top right:

• Mercury, just above the horizon between the low cloud bands, at lower left
• Jupiter, bright at centre
• Mars, reddish and above Jupiter
• Venus, brightest at upper right and in some thin cloud.

The bright star Regulus in Leo is above and to the left of Venus.

The waning crescent Moon, lit by Earthshine, with four planets on the morning of October 9, 2015, with the planets from bottom left to top right: • Mercury, just above the horizon between the low cloud bands, at lower left • Jupiter, bright at centre • Mars, reddish and above Jupiter • Venus, brightest at upper right and in some thin cloud.  The bright star Regulus in Leo is above and to the left of Venus. This is a blend of four exposures: a long 4-second exposure for most of the sky and ground and shorter 2, 1, amd 1/2 second exposures for the bright twilight area and around the Moon and Venus, to prevent those areas fro being blown out. Blending is with masks, not HDR. All with the Canon 6D at ISO 400 and 50mm Sigma lens at f/2.5

Above is an unlabeled version of the image.

TECHNICAL:

It’s a blend of four exposures: a long 4-second exposure for most of the sky and ground, plus shorter 2, 1, and 1/2 second exposures for the bright twilight area and around the Moon and Venus, to prevent those areas from being blown out. Blending is with masks, not HDR. All were shot with the Canon 6D at ISO 400 and 50mm Sigma lens at f/2.5.

– Alan, October 9, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Evening Stars Over the Red Deer River


Evening Stars Over Red Deer River

Mercury and Venus shine as “evening stars” over the Red Deer River in southern Alberta.

What a fine night this was for nightscape shooting. Mercury and Venus are both now about as high as they will get for the year in the evening sky from my western Canadian latitude.

Venus is easy to spot as the brilliant object in the west. But Mercury is more elusive. You can see it here low in the twilight glow and much dimmer than Venus.

The photo illustrates how far each of the two inner planets swings away from the Sun in our skies, and why Mercury has its reputation for being difficult to sight. Also, it appears at its best for only a couple of weeks at a time. By mid-May it will be gone.

Venus, however, continues to dominate our western sky for the next two months.

I shot the main photo from the deck of a rickety wooden bridge over the Red Deer River near Dorothy, Alberta, just off Highway 10 east of Drumheller in the Badlands.

The image is a high-dynamic-range “HDR” stack of five exposures.

Venus over the Atlas Coal Mine

Shortly after taking the lead photo, I drove west to the Atlas Coal Mine to shoot it by the light of the now high and nearly Full Moon. Mercury can still be seen low and to the right of the historic tipple building. Venus shines above it.

This is a single 25-second exposure at ISO 800.

The Atlas Coal Mine is now a National Historic Site and is the last standing from what was once a booming coal mining centre in the Red Deer River Valley.

Now, mostly dinosaur fossils are unearthed here.

– Alan, May 3, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Mercury Rising


May 6 Mercury

The next two weeks are the best in 2015 for sighting Mercury in the evening sky.

Mercury is coming into view in our evening sky, climbing as high as it can get for us in the Northern Hemisphere. This is our best chance for us to sight Mercury as an evening star in 2015.

Spring is always the best time to catch elusive Mercury. The angle of the ecliptic – the path of the planets – swings up highest above the horizon in spring, putting Mercury as high into the evening twilight as it can get. This makes it easier to sight Mercury than at other times of the year when, particularly for observers at northern latitudes, Mercury can be lost in the twilight glow and horizon haze.

When it is at its highest Mercury is surprisingly bright, appearing as a bright star easily visible to the naked eye. However, locating it at first in the twilight usually requires a scan with binoculars.

Mercury will be at its highest on May 6 when it reaches “greatest elongation.” However, it will be almost as good for a week on either side of that date.

So set aside a clear evening during the first two weeks of May to search for the inner planet. (The green line is Mercury’s path relative to the horizon with the green dots marking its position at daily intervals.)

Mercury will be shining above fainter Mars, and well below brilliant Venus, now dominating our evening spring sky. Look north of due west during the hour after sunset.

Mercury & Venus Conjunction Closeup (Jan. 10, 2015)
Mercury and Venus on January 10, 2015 from New Mexico.

This view captures Mercury at its last good evening appearance, back in early January when it appeared close to Venus, then emerging into the evening sky. You can compare their relative brightness.

By coincidence, the emergence of Mercury into our evening sky comes just as it loses its lone visitor from Earth. Since 2011, NASA’s Messenger probe has been orbiting and mapping Mercury.

On April 29, with the probe exhausted of its maneuvering fuel, Messenger is scheduled to end its mission by crashing onto the planet, adding a new crater to Mercury’s barren and volcanic surface.

A global false-color map of the mineral composition of Mercury from Messenger data.
A global false-color map of the mineral composition of Mercury from Messenger data.

This is a recent map of Mercury from Messenger. For more details, see the mission’s website.

– Alan, April 30, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! – Dual Conjunctions in the Spring Sky


April 21 Moon & Venus

On the evening of April 21 the waxing Moon shines near Venus, while Mercury appears near Mars.

Say goodbye to the winter sky, as Orion and Taurus sink into the western twilight. Joining them is an array of planets, and the Moon.

Look west on April 21 and you’ll see the waxing crescent Moon near brilliant Venus, with both above the Hyades star cluster and the bright star Aldebaran in Taurus.

The thinner Moon will appear below Venus the night before, on April 21, while on April 22, the waxing Moon, then a wider crescent, will sit well above Venus.

If you have an unobstructed view to the west also look for the pairing of Mercury and Mars low in the twilight. You might need to use binoculars to pick them out.

Mercury is just beginning its best evening appearance of the year for the northern hemisphere. So if you miss it April 21, you have another couple of weeks to find it in the evening sky.

Waxing Moon Amid the Hyades (Telescope)

On the nights around April 21, also look for Earthshine lighting the dark side of the Moon. You can see the night side of the Moon because it is being illuminated by sunlight reflecting off the Earth, shining brightly in the lunar sky.

The above image is a view of Earthshine from a month ago, on March 24, when the Moon appeared in the Hyades star cluster.

Enjoy the spring sky adorned by Venus as a bright “evening star,” and joined by the Moon on April 21.

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