A Panorama of the Entire Northern Milky Way
By: Alan Dyer
Category: Milky Way
|Camera:||Canon EOS 5D Mark II|
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.
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…
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.”
For larger images, see my Flickr site at https://www.flickr.com/photos/amazingsky/
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