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

 

A Panorama of the Entire Northern Milky Way


Panorama of the Northern Milky Way

In a sweeping panorama, here is the entire northern hemisphere Milky Way from horizon to horizon.

This is the result of one of the major projects on my recent trek to Arizona and New Mexico – a mosaic of images shot along the Milky Way over several hours.

The goal is a complete 360° panorama of the entire Milky Way, and I’ve got most of the other segments in previous shoots from Alberta, Australia and Chile. But I did not have good shots of the northern autumn segments, until now.

The panorama sweeps from Cygnus (at top, setting in the western sky in the evening), across the sky overhead in Perseus, Auriga and Taurus (in the middle), and down into Orion, Canis Major, and Puppis (at bottom, low in the southern sky at midnight).

The view is looking outward to the near edge of our Milky Way, in the direction opposite the centre of our Galaxy. In this direction the Milky Way becomes dimmer and less defined. Notable are the many red H-alpha emission regions along the Milky Way, as well as the many lanes of dark interstellar dust nearby and obscuring the more distant stars.

However, a diffuse glow in Taurus partly obscures its Taurus Dark Clouds — that’s the Gegenschein, caused by sunlight reflecting off cometary dust particles directly opposite the Sun and marking the anti-solar point this night, by coincidence then close to galactic longitude of 180° opposite the galactic centre.

Panorama of the Northern Milky Way (with Labels)

Here I provide a guided map of the mosaic. Orion is at lower right, while the Pleiades and Andromeda Galaxy lie near the right edge. The Andromeda Galaxy is the only thing in this image that is not part of the Milky Way.

The bright star Canopus is just rising at bottom, in haze. Vega and Altair are just setting at the very top. So the panorama sweeps from Altair to Canopus.

The sky isn’t perfect! Haze and airglow in our atmosphere add discolouration, especially close to the horizon. In my final 360° pan, I’ll use only the central portions of this panorama.

Now let’s put the horizon-to-horizon panorama into cosmic perspective…

Illustration of the Northern Milky Way Panorama

In this diagram, based on art from NASA’s Spitzer Space Telescope Institute, I show my Northern Milky Way Panorama in perspective to the “big picture” of our entire Galaxy, using artwork based on our best map of how our Galaxy is thought to look.

We are looking in a “god’s eye” view across our Galaxy from a vantage point on the far side of the Galaxy.

Where we are is marked with the red dot, the location of our average Sun in a minor spiral arm called the Orion Spur.

The diagram places my panorama image in the approximate correct location to show where its features are in our Galaxy. As such it illustrates how my panorama taken from Earth shows our view of the outer portions of our Galaxy, from the bright Cygnus area at right, to Perseus in the middle, directly opposite the centre of the Galaxy, then over to Orion at left.

The panorama sweeps from a “galactic longitude” of roughly 90° at right in Cygnus, to 180° in Perseus, over to 240° in Orion and Canis Major at left.

In the northern autumn and early winter seasons we are looking outward toward the outer Perseus Arm. So the Milky Way we see in our sky is fainter than in mid-summer when we are looking the other way, toward the dense centre of the Galaxy and the rich inner Norma and Sagittarius arms.

Yet, this outer region contains a rich array of star-forming regions, which mostly show up as the red nebulas. But this region of the Milky Way is also laced with dark lanes of interstellar “stardust.”

NOTE:

For larger images, see my Flickr site at https://www.flickr.com/photos/amazingsky/

TECHNICAL:

The panorama is composed of 14 segments, most being stacks 5 x 2.5-minute exposures with the filter-modified Canon 5D MkII at ISO 1600 and 35mm lens at f/2.8.

The end segments near the horizons at top and bottom are stacks of 2 x 2.5-minute exposures.

Each segment also has an additional image shot through a Kenko Softon filter to add the star glows, to make the bright stars show up better.

The camera was oriented with the long dimension of the frame across the Milky Way, not along it, to maximize the amount of sky framed on either side of the Milky Way.

The camera was on the iOptron Sky-Tracker. I shot the segments for this pan from Quailway Cottage, Arizona on December 8/9, 2015, with the end segments taken Dec 10/11, 2015. I decided to add in the horizon segments for completeness, and so shot those two nights later when sky conditions were a little different.

— Alan, December 19, 2015 / © 2015 Alan Dyer / www.amazingsky.com