The Milky Way is a barred spiral galaxy some 100,000–120,000 light-years in diameter, which contains 100–400 billion stars. It may contain at least as many planets as well. The Solar System is located within the disk, about 27,000 light-years away from the Galactic Center, on the inner edge of one of the spiral-shaped concentrations of gas and dust called the Orion Arm. The stars in the inner ≈10,000 light-years form a bulge and one or more bars that radiate from the bulge. The very center is marked by an intense radio source named, Sagittarius A*, which is likely to be a supermassive black hole.
Stars and gases at a wide range of distances from the Galactic center orbit at approximately 220 kilometers per second. The constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way does not emit or absorb electromagnetic radiation. This mass has been given the name “dark matter”. The rotational period is about 240 million years at the position of the Sun. The Galaxy as a whole is moving at a velocity of approximately 600 km per second with respect to extragalactic frames of reference. The oldest known star in the Galaxy is at least 13.6 billion years old and thus must have formed shortly after the Big Bang. Surrounded by several smaller satellite galaxies, the Milky Way is part of the Local Group of galaxies, which forms a subcomponent of the Virgo Supercluster.
I’d be interested to know if others see pixelization in the sky area of this photo. It looked fine on my computer at home (macbook pro w/Retina). But then I looked at it on bigger screen and the pixelization was terrible. So this larger file hopefully fixes that problem.
Taken with Nikon D610 on tripod. The image is made from 3 different photos and blended in Photoshop. First image is the foreground taken with low ISO for clarity. The second image was taken a few minutes later to get brilliant oranges on horizon as glow from sun was leaving quickly. The last image was about 30 minutes later to get stars.
Acadia National Park, Maine
The view of Otter Cliffs from Boulder Beach is one of the classic sights in Acadia, but it took me a few trips to Acadia before I finally went there and was able to photograph it at night. Prior to my last trip, all my trips to Acadia had ended up with lots of clouds and fog, but last week I was lucky to get a few clear nights.
In my astrophotography presentations, after I mention the blending of multiple exposures I use to achieve these photos, I sometimes get asked how much time goes into the editing of a photo. For this photo it was over 4 hours of processing on the computer. This photo is a blend of 14 exposures, although logically it is a blend of 5 images. What do I mean by that? I used 10 images of the sky at ISO 6400 for 10 seconds each to create a single image of the sky that has less noise and near pinpoint stars using the Starry Landscape Stacker (http://ift.tt/1iZwUI9) software for Mac. Then I used 4 other foreground exposures to blend with the sky image to create the entire image, having everything in focus from the foreground to the background. After that, lots of work in Lightroom and Photoshop to “mold” my final image.
You can read much more about my process in my tutorial “Introduction to Landscape Astrophotography” on the Luminous Landscape website: http://ift.tt/1nQqJxM
#astrophotography #acadia #maine #milkyway #night #stars