Various resolution downloads:
[Scaled 1/8th: 2350x2400 pixels - JPEG - 1,0Mb] 
[Scaled 1/16th: 1175x1200 pixels - JPEG - 256Kb] 
[Scaled 1/32th: 588x600 pixels - JPEG - 87Kb] 

Scientific description:
The Rosette Nebula is a huge cloud of glowing gas heated by stars created only a few million years ago when a giant molecular cloud collapsed. The newborn open cluster that now stands in its center is NGC 2244. It contains many hot, bright stars that are emitting copious quantities of ultra-violet light. Such radiation strips electrons from interstellar gas atoms, turning the atoms into ions, and the gas into a glowing plasma. Ionized hydrogen emits a very intense red light and oxygen ions emit green light. Mixing the light from these two common elements gives the yellow color seen on this image. Interestingly, the abundance of gaseous oxygen revealed by images such as these, and similar studies, points out that several generations of stars must have contributed to the enrichment of the original molecular cloud over the billions of years of evolution of our galaxy. The cycle of star birth, death and rebirth will continue for billions of years to come. 

Another consequence of the high energy radiation from the massive stars in NGC 2244 is the hole cleared in the center of the nebula. Within a few tens of million years, this spectacular cloud complex will have disappeared, leaving perhaps a trace of dust that might form a reflection nebula similar to that seen near Messier 35. The interstellar dust is mixed with the gas and is very efficient at scattering and absorbing starlight. Dense pockets and lanes of dust create striking silhouettes across the Rosette. 

The Rosette Nebula lies in our galaxy approximately 5,000 light years away from us. This image spans about 90 light years across, more than 65,000 times the size of our solar system! 

Technical description:
MegaPrime / MegaCam (central 36 CCDs - 18Kx18K pixels)
Field of view: 60'x60' (1 square degree)
Filters used: u', g', r' (semi true-colors)
Exposure times: 5 minutes total per filter
Observed at the CFHT in February 2003

Credit line: "Canada-France-Hawaii Telescope / 2003"

Copyright © 2003 Canada-France-Hawaii Telescope Corporation

Various resolution downloads:
[877x894 pixels - JPEG - 128Kb] 

Scientific description:
The Canada-France-Hawaii Telescope has been probing the Universe with its giant CCD cameras for years (starting with a 16 megapixels in 1994, a 64 megapixels in 1995, and a 100 megapixels since 1999, the CFH12K) using the same optical wavelengths detected by the human eye. Now our eye-brain combination distinguishes the gradation of wavelengths, from short to long, as color that ranges from the blue to red. The images acquired with our digital CCD cameras are not colored as seen in these pages. To make the pictures seen here, we follow a technique often used in high-quality commercial printing and shoot through three separate filters (blue, green, red). Our new system, the camera MegaCam mounted in MegaPrime is a mosaic of 36 CCD chips (a total of 340 megapixels) and there are physical gaps between them as shown on this image. To avoid images with a window-pane look, we must take several offset shots in each color and stack these to erase the appearance of the gaps. Just as CCDs are surrogates for our eyes, computers become surrogates for our brains. In the end, we combine all the data on a computer, typically spending about 10 to 15 hours to achieve a visually striking and harmonious result. The images seen here are designed to show "true colors". They are a peek at the distant universe that would be seen with a naked human eye, but only if that eye were 4 meters in diameter and was sensitive to 90% of the incident light. Compare that to our modest 3 millimeters wide pupils and couple of percent sensitivity! 

Technical description:
MegaPrime / MegaCam (central 36 CCDs - 18Kx18K pixels)
Field of view: 60'x60' (1 square degree)
Filter used: r' (levels of intensity)
Exposure times: 5 minutes total
Observed at the CFHT in February 2003

Credit line: "Canada-France-Hawaii Telescope / 2003"

Copyright © 2003 Canada-France-Hawaii Telescope Corporation