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 Wonder-Filled Winter Sky


Mosaic of the Wonder-filled Winter Milky Way

The sky of December contains an amazing array of bright stars and deep-sky delights.

At this time of year we peer out toward the edge of our Galaxy, in the direction opposite to what we see in July and August. Even though we are looking away from the centre of our Galaxy, the Milky Way at this time of year contains a stunning collection of sights – for the naked eye, binoculars or a telescope.

I can’t list them all here, but most are in the lead image above! The image is a mosaic of the northern winter Milky Way, including the brilliant stars and constellations in and around Orion the Hunter.

The Milky Way extends from Perseus in the north at top, to Canis Major in the south at bottom. Throughout the scene are dark lanes and dust clouds, such as the Taurus Dark Clouds at upper right.

The Milky Way is dotted with numerous red “hydrogen-alpha” regions of emission nebulosity, such as the bright Rosette Nebula at lower left and the California Nebula at upper right. The curving arc of Barnard’s Loop surrounds the east side of Orion. Orion is below centre, with Sirius, the night sky’s brightest star, at lower left.

The constellation of Taurus is at upper right and Gemini at upper left. Auriga is at top and Perseus at upper right.

There’s an unusually bright area in Taurus just right of centre in the mosaic which I thought might be an image processing artifact. No. It’s the Gegenschein – a glow of sunlight reflected off comet dust directly opposite the Sun.

Two highlights of this sky that are great regions for binoculars are the Hyades cluster in Taurus ….

The Hyades Cluster with Aldebaran
The Hyades open star cluster in Taurus with the bright star Aldebaran, not a part of the cluster iteslf. The smaller and more distant cluster NGC 1647 is at left. This is a telephoto lens image taking in a field similar to binoculars, and is a stack of 5 x 2.5-minute exposures with the 135mm lens at f/2 and Canon 5D MkII camera at ISO 800, plus two other exposures taken through the Kenko Softon filter to add the star glows. Taken from Quailway Cottage on Dec 7, 2015 using the iOptron Sky-Tracker.

…and the Belt and Sword of Orion.

The Hyades – the face of Taurus – is one of the nearest and therefore largest open star clusters.

Orion the Hunter, who battles Taurus in the sky, contains the famous Orion Nebula, here overexposed in order to bring out the much fainter nebulosity in the region.

The magenta and blue arcs in the image below are photographic targets, but the bright Orion Nebula in Orion’s Sword is easy in binoculars, shining below the trio of his Belt Stars.

Orion Belt and Sword Mosaic
A mosaic of the Sword and Belt region of Orion the Hunter, showing the diverse array of colourful nebulas in the area, including: curving Barnard’s Loop, the Horsehead Nebula below the left star of the Belt, Alnitak, and the Orion Nebula itself as the bright region in the Sword. Also in the field are numerous faint blue reflection nebulas. The reflection nebula M78 is at top embedded in a dark nebula, and the pinkish NGC 2024 or Flame Nebula is above Alnitak. The bright orange-red star at far right is W Orionis, a type M4 long-period variable star. This is a 4-panel mosaic with each panel made of 5 x 2.5-minute exposures with the 135mm Canon L-series telephoto wide open at f/2 and the filter-modified Canon 5D MkII at ISO 1250. The night was somewhat hazy which added natural glows on the stars. No filter was employed here. The camera was on the iOptron Sky-Tracker for tracking but no guiding. Shot from outside Quailway Cottage near Portal, Arizona, Dec 7, 2015. All stacking and stitching performed in Photoshop CC 2015. Stacking done with median combine stack mode to eliminate geosat trails through the fields.

For us in the northern hemisphere, Orion and company are winter sights. But for those down under, in the southern hemisphere, this is the summer sky. So pardon the northern chauvinism in the title!

Either way, on a dark, moonless night, get out and explore the sky around Orion.

TECHNICAL:

I shot the segments for the main mosaic at top on a very clear night on December 5, 2015 from the Quailway Cottage at Portal, Arizona. This is a mosaic of 8 segments, in two columns of 4 rows, with generous overlap. Each segment was made of 4 x 2.5-minute exposures stacked with mean combine stack mode to reduce noise, plus 2 x 2.5-minute exposures taken through the Kenko Softon filter layered in with Lighten belnd mode to add the star glows. Each segment was shot at f/2.8 with the original 35mm Canon L-series lens and the filter-modified (by Hutech) Canon 5D MkII at ISO 1600, riding on the iOptron Sky-Tracker. All stacking and stitching in Photoshop CC 2015. The soft diffusion filter helps bring out the star colors in this area of sky rich in brilliant giant stars.

— Alan, December 11, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Moon Amid the Hyades


Waxing Moon Amid the Hyades (March 24, 2015)

The waxing crescent Moon shines amid the stars of the Hyades cluster.

I shot these on the evening of March 24 when, from western North America, the Moon appeared superimposed in front of the sprawling Hyades star cluster in Taurus.

The main image at top is with a 200mm telephoto lens and takes in most of the Hyades and the bright red star Aldebaran at lower left. Unfortunately, it also includes a blue lens flare from the brilliant and overexposed crescent, a tough element to “photoshop” out.

The image is a high dynamic range stack of 3 exposures. Even so, I purposely overexposed the Moon to bring out the stars and their colours.

Waxing Moon Amid the Hyades (Telescope)

This close up of the Moon includes fewer Hyades stars, but with the Moon centred I was able to avoid the lens flare. It’s an HDR stack of 5 exposures, to capture details in the sunlit crescent as well as on the dark side of the Moon lit by blue Earthshine.

These are the last telescopic shots from my winter in New Mexico, as the telescope and mount gets packed up tomorrow, in preparation for the trip back to Canada.

It’s been a fabulous winter of sky shooting, with some 500 gigabytes of images shot, processed, and archived!

– Alan, March 24, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Lovejoy Passes the Pleiades


Comet Lovejoy and the Pleiades (Jan 18, 2015)

Tonight Comet Lovejoy paired with the Pleiades star cluster.

Sunday, January 18 was the night to catch the ever-photogenic Comet Lovejoy at its best and closest to the Seven Sisters, the Pleiades. Its long blue ion tail stretched back past the Pleiades.

I thought the tail would be passing right over the star cluster, but not so. At least not when I was shooting it at about 7:30 pm MST.

Still, the combination made a fine pairing of cosmic blue objects for the camera. The top image is with a 135mm telephoto.

Comet Lovejoy in the Winter Sky (Jan 18, 2015)

This wide-angle image, with a 24mm lens, takes in many of the northern winter constellations, from Orion at bottom, to Auriga at top, with Taurus in the middle. Notice the dark tendrils of the Taurus Dark Clouds.

At right, beside the Pleiades, is the green and blue comet, with its tail reaching back past the Pleiades.

I shot both images from the dark skies of City of Rocks State Park, New Mexico, which has proven to be one of the finest places on the planet for watching Lovejoy!

– Alan, January 18, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

Night of the Comet


Comet Lovejoy's Long Ion Tail in Taurus

What a beautifully photogenic comet Lovejoy is proving to be! 

On Friday, January 16, I caught Comet Lovejoy crossing the ecliptic as it travels through Taurus. The long exposure above shows it amid the star clusters, nebulas, and dark clouds of Taurus and Perseus.

The blue Pleiades is at centre, and the red California Nebula is at top. Throughout are the dark tendrils of the dusty Taurus Dark Clouds.

The long blue ion tail of Lovejoy now extends back 15° to 20° on photos and is easy to trace for half that distance in binoculars in a dark sky.

I turned the top photo 90° to orient the comet so it points “down.”

Comet Lovejoy Nightscape (Jan 16, 2015)

However, this wide-angle nightscape shows the real orientation of the comet, high in the sky above Orion, here rising over the rock formations of City of Rocks State Park, my favourite dark sky site in this area of New Mexico.

Comet Lovejoy Crossing the Ecliptic (Jan 16, 2015)

Taken earlier in the evening, this ultra-wide image shows the comet at top, with its blue tail oriented along the ecliptic and aligned with the Zodiacal Light, from the glow of sunlight reflecting off comet dust in the inner solar system.

The Zodiacal Light follows the ecliptic, the plane of the solar system and where we find the planets, such as Mars and Venus at bottom here. The comet seems to point toward the Sun, now below the horizon here at the base of the Zodiacal Light. That’s just as it should be! Comet gas tails always point away from the Sun, as they are blown away from the comet’s head by the solar wind.

This night Comet Lovejoy was crossing the ecliptic, as its orbit continues to take it north in a path almost perpendicular to the ecliptic. While planets orbit in the ecliptic plane, most comets do not. They can have orbits oriented at all kinds of angles off the ecliptic plane.

But on January 16 Comet Lovejoy crossed the ecliptic, placing it at the apex of the Zodiacal Light.

Comet Lovejoy & Zodiacal Light (Jan 16, 2015)

This wider view takes in the Zodiacal Light, the comet and Orion rising at left.

This was a marvellous “night of the comet.”

— Alan, January 17, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

Finding Lovejoy in the Stars


Comet Lovejoy near Pleiades

The coming week is the best time to sight Comet Lovejoy as it sails through Taurus.

Here’s a finder chart for locating Comet Lovejoy (C/2014 Q2) over the next week as it climbs higher in our southern sky. It is well-placed high in the south as it gets dark each evening.

Unfortunately, it doesn’t pass near any really bright stars to serve as a convenient jumping off point for finding the comet. Look west (right) of the stars of Taurus the bull and the bright star Aldebaran by 2 to 3 binocular fields. In a dark sky, look for a fuzzy star in your binoculars. Once you find it with optics, if your sky is dark enough, you should be able to see it naked eye, but only just. In the city, forget it!

On the nights of January 17 to 19 Comet Lovejoy will be just over a binocular field to the right (west) of the distinctive Pleiades star cluster, marked here as M45, for Messier 45.

Comet Lovejoy in Taurus (Jan 10, 2015)

Here’s the comet as it appeared on Saturday night, January 10, with it west of the V-shaped Hyades star cluster marking the head of Taurus and well below the Pleiades at top.

Comet Lovejoy's Long Ion Tail

This is a closer view, with a telephoto lens, of the comet from Sunday night, January 11, showing how its faint blue ion tail stretches back several degrees. However, only the long exposures used here pick up the full extent of the tail. Visually, even through binoculars, just a hint of a tail is visible extending to the left away from the large fuzzy coma, or head of the comet.

Comet Lovejoy Thru the Telescope (Jan 11, 2015)

This is a closer view of the coma and ion tail, shot through a telescope on Sunday night, January 11. It shows some of the fine structure in the ion tail that is changing hourly and nightly, shaped in part by gusts of solar wind.

The comet is now at at its brightest, while the evening sky is now dark and moonless. So head to a dark sky site, keep warm, and look up to enjoy our winter comet, coming to us from Australia where it was discovered by Terry Lovejoy.

Chart courtesy Starry Night™/Simulation Curriculum.

– Alan, January 11, 2015 / © 2015 Alan Dyer / www.amazingsky.com

The Seven Sisters in a Silver Braid


M45 Pleiades Star Cluster, the Seven Sisters“Many a night I saw the Pleiads, rising thro’ the mellow shade,

Glitter like a swarm of fireflies tangled in a silver braid.”

– Alfred, Lord Tennyson

These are the famous Seven Sisters, the Pleiades, caught two nights ago in New Mexico skies. This bright star cluster stands out easily to the unaided eye in the winter sky, shining in the shoulder of Taurus.

What the eye does not see is the “silver braid” – the dim dust that surrounds the Pleiades. The stars light the dust, causing it to shine blue near the stars. Farther out, the dust is much dimmer and glows with pale tints of cyan and red.

The dust clouds were once thought to be what was leftover from the formation of the stars, now estimated to have occurred about 100 million years ago. However, current theory suggests that the natal dust of the Pleiads would have long since dispersed.

Instead, the silvery braids of dust that surround the Seven Sisters are just nearby dust clouds in Taurus that the stars are passing through, and illuminating with their hot blue light.

The Pleiades, as familiar as they are – they have been mentioned in ancient texts and myths dating back thousand of years – remain a source of scientific controversy. Astronomers argue over their distance, with different methods providing different results. But the best recent measurement puts them 440 light years away.

Technical notes: This is a stack of 10 x 12 minute exposures at ISO 400 with the Canon 5D MkII camera and 92mm TMB refractor at f/4.4. I shot the images November 16 from near Silver City, New Mexico.

– Alan, November 18, 2014 / © 2014 Alan Dyer