Observers: F. Colas, J. Lecacheux, E. Frappa
Location: Pic du Midi Observatory, France
Date: March 26, 1996 01:00 UT
We used two filters :
The "C2+continuum" (#1) image was recorded through an interferential filter centered at 515 nanometers. Its FWHM was 8 nanometers. The exposure duration was 9 minutes. Pixel binning of 4x4 was selected to boost the sensitivity of the detector, giving a scale of 0.85 arc-second per pixel.
The "continuum" (#2) image was taken using a Schott RG 830 e=3 mm. The exposure time was 25 minutes, with binning 2x2 giving a scale of 0.425 arc-second per pixel. This filter is not a perfect continuum filter, but as the sky transparency was rapidly declining, broadband was needed.
To obtain the final "C2" image, we scaled the image #1 to the same format than image #2 (i.e. 768x512), then we made the following substraction : Image #1 - K * Image #2 where the K coefficient was chosen in order to cancel the dust tail.
Observers : F.Colas, J.Lecacheux, E.Frappa
Comet 1996 B2 Hyakutake Home Page