Milky Way Panorama 2.0
Between October 2007 and August 2009, I assembled a new digital all-sky mosaic image 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
For more details, see
, published in PASP
121, 1180-1187 (2009)
The image is also at the heart of the Cambridge Photographic Star Atlas
(in English) and the Fotografischer Sternatlas
Viewing the Panorama
Click on the image