NOAO/KPNO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative agreement with the National Science Foundation
Comet Hale-Bopp in the 1-3 micron Infrared: The inner coma of Comet Hale is shown from infrared data taken with the 2.1 meter telescope on March 21, 1997. All of the images were taken during daytime. Since sky is blue, the infrared sky is much darker than the visual sky. Comet Hale-Bopp was bright enough that it was easily visible in the infrared day sky.
The images were taken using the acquisition mode of the high resolution infrared spectrograph Phoenix. In acquisition mode, the spectrograph takes infrared images with a 1 arcminute field of view. For Comet Hale-Bopp on March 21 the images show 60,000 km of the inner coma. The images were taken through filters with band passes of between 1 and 3 percent.
This time series of five
images at a wavelength of 2.37 microns (a frequency of 4220 cm-1)
shows the rotation of the inner coma detectable over an interval of
a little less than 3 hours.
A set of
four images were also taken at wavelengths spanning the near infrared:
1.21, 2.42, 3.05, and 3.30 microns. These were combined into two false
color images by assigning 3.05 microns to red, 2.42 microns to green,
and 1.21 microns to blue and 3.30 microns to red, 3.05 microns to green,
and 2.42 microns to blue. These images show that the inner coma has
little change of brightness with infrared color but that the more extended
regions are enhanced in the 3 micron region.
The images were provided courtesy of Ken Hinkle at NOAO. Image reduction and enhancements were done by Nigel Sharp (NOAO).