Milky Way Panorama 2.0


Observing Sites

Top to bottom: Cederberg Observatory (South Africa), Koornlandskloof Guest Farm (South Africa), Big Bend National Park (Texas, USA)

Observing Sites

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 and SWarp.

Cambridge Photographic Star Atlas For more details, see this paper, 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 (in German).

NEW: Poster prints available through Zazzle.

Viewing the Panorama

Click on the image below (an all-sky view in Hammer-Aitoff projection) to see a zoomable Flash-based panorama with hotspots for Messier and NGC objects. If you don't have Flash, here is the older Javascript-based zoomable Mercator projection.

Hammer-Aitoff projection