Axel Mellinger's

All-Sky Milky Way Panorama 2.0

Between October 2007 and August 2009, a new digital all-sky mosaic image was assembled from more than 3000 individual CCD frames. Using an SBIG STL-11000 camera, 70 fields (each covering 40° × 27°) were imaged from dark-sky locations in South Africa, Texas and Michigan. In order to increase the dynamic range beyond the 16 bits of the camera's analog-to-digital converter (of which approx. 12 bits provide data above the noise level), three different exposure times (240 s, 15 s and 0.5 s) were used. Five frames were taken for each exposure time and filter setting. The fields were photometrically calibrated using standard catalog stars and sky background data from the Pioneer 10 and 11 space probes. The new panorama has an image scale of 36 arcsec/pixel (approx. 3× the resolution of the old, film-based mosaic), a limiting magnitude of approx. 14 mag and an 18 bit dynamic range. At full resolution and bit depth, it is a 648 MPixel, 7.7 GByte FITS cube. Unlike the old image, the new panorama was carefully calibrated to preserve the large-scale star and dust clouds.

The image was processed on a Linux PC with an Intel Core2 Quad (Q9400) CPU and 16 GB of RAM. Due to the large number of repetitive tasks (dark-frame subtraction, flat-fielding, astrometric calibration), a processing pipeline was developed. Its primary components are IRAF, Source Extractor and SWarp.

For more details, see this paper, published in PASP 121, 1180-1187 (2009).

News and press releases:

Oct. 28, 2009: Press release by University of Chicago Press.
Nov. 6, 2009: Press release and video by Central Michigan University
Nov. 24, 2009: Scientist Takes Pictures of Entire Sky on ABC News
Nov. 25, 2009: The Milky Way panorama is featured as NASA's Astronomy Picture of the Day

The new Milky Way panorama in Hammer-Aitoff projection. Click on the image to see a zoomable Mercator projection.

Interested in the image?

Science users: here is a medium-resolution (3600×1800) FITS cube with WCS header. For higher resolution, please email me, stating the intended use of the image. Please allow a few days for my reply.
If you use my image in a publication, please acknowledge the source as follows:
Axel Mellinger, A Color All-Sky Panorama Image of the Milky Way, Publ. Astron. Soc. Pacific 121, 1180-1187 (2009).
Personal use: Follow the download links for Mercator and Hammer-Aitoff projections (each 2000 pixels wide).
Higher resolutions, commercial & educational use: In most cases, this will require payment of a license fee (unfortunately, camera equipment and intercontinental travel do not come for free…). Please contact my business partner for license information and pricing (provide as much information as possible on the intended use, as well as your preferred projection and resolution):
EKTECH Köhler GmbH
Werrastr. 1a
12059 Berlin
Germany

Email:

HRB 31686, AG Berlin-Charlottenburg
Geschäftsführer: Dipl.-Phys. Eberhard Köhler
Umsatzsteuer-ID-Nr. (VAT-ID-No.): DE 136 778 723

… and here is the older, film-based panorama image:

Axel Mellinger's

All-Sky Milky Way Panorama

Milky Way filmstrip

History

By 1996, RAM prices had dropped low enough to allow the processing of high-resolution digitized astrophotos on a home PC. My early attempts included contrast stretching and image stacking, as shown in this example. Faced with the limited field of view and grain-limited resolution of photographs taken on 35 mm film, I decided to venture further into the field of digital image processing and explore the possibilities of stitching together several images into a single high-resolution mosaic.

Three years and 51 wide-angle images later, an All-Sky panorama was completed. The individual photographs were taken on Kodak PJM-2 and PJ-400 film with a Minolta SRT-101 or XD-5 camera equipped with a 28 mm lens and riding piggyback on my Super Polaris DX mount. Exposure times at f/4 were ranging from 30 to 45 minutes. My observing sites were places as far apart as California's White Mountain Range and Cederberg Observatory in South Africa's Western Cape Province. A special transformation technique was used to eliminate distortions introduced by the camera lens. Thanks to computer processing, the image can be presented in a variety of different views. Shown here are an Aitoff projection in galactic coordinates (left) and an equidistant azimuthal (polar) projection (right). At full resolution (not displayed here for obvious reasons) the file size is 300 MB.

The image is part of NASA's Multiwavelength Milky Way poster (the only contribution from an amateur astronomer!).

Click on the images to view them in full size.

Confused by the vast number of stars? Can't find the constellations? Here is a strip centered on the galactic equator with constellation outlines.

Click here to see a Virtual Reality All-Sky Panorama!

Articles

An article describing the digital processing steps of the film-based panorama is available as HTML for online viewing and PDF for printing.
D. di Cicco, "There's No Place Like Home", Sky and Telescope, Nov. 1999, pp. 137-140.
A. Mellinger, "Die Milchstraße im Computer: Entstehung eines Himmelspanoramas", Sterne und Weltraum, p. 174, Feb./March 2000.
K. Kizer Whitt and A. Mellinger, "The Milky Way from the inside'', Astronomy 29(11), 58 - 63 (2001).
An article about the (film-based) panorama (Star Forming Regions along the Milky Way: A Panoramic View) is the first chapter in the Handbook of Star Forming Regions, Bo Reipurth (ed.), Vol. I, Astronomical Society of the Pacific, 2008.
An article about the new panorama is available on arXiv/astro-ph.

Purchasing prints and high-resolution electronic images

Sky Publishing Corporation is selling two different poster versions of the panorama:
- A galactic projection called "The Milky Way", showing the sky within +/-40 degrees of the galactic equator
- An equidistant azimuthal projection (called "The Celestial Sphere") showing the entire northern and southern hemisphere of the sky.
For details, please visit their online store and go to the "Posters" product category.
For high-quality custom size prints, check out Hutech's web site.
For high-resolution electronic files, please email me.
In 2002, Kosmos published a star atlas (in German) based on the panorama image.
New 2008 edition:

Axel Mellinger, Susanne M. Hoffmann:
Der große Kosmos-Himmelsatlas
English edition published by Firefly Books Ltd.:

Axel Mellinger, Susanne M. Hoffmann:
The New Atlas of the Stars

Other images