October 9.945, 2012 observation
C9 telescope (D = 0.235 m)
LISA Spectrograph at R = 750 (35 microns slit)
Atik 460EX+ CCD camera (binning 2x2)
Castanet-Tolosan Observatory (France)
Exposure : 5 x 600 s
Image of comet given by LISA guiding camera. Right, during acquisition phase.
2D composite spectrum (before flat-field correction, coloration is artificial)
Ratio of comet spectrum and HD134411 star spectrum (G2V star, solar equivalent objet). The ratio elliminate Sun signature. Note the flat aspect of dust reflectance spectrum.
The comet is gaz free object for the date. Ultraviolet CN line is prominent. [OI] lines are also detect.
David Schleicher, Lowell Observatory, reports from narrowband photometry on Oct. 9 (see IAU Electronic Telegram No 3257) that the comet is strongly carbon-chain depleted
(cf. A'Hearn et al. 1995, Icarus 118, 223), by even more than that of comet 21P/Giacobini-Zinner, the proto-type of this class.
Download observed spectrum: _168p_hergenrother_flat_20121009_945_cbuil.fit
Download ratio spectrum: _168p_hergenrother_flat_20121009_945_2_cbuil.fit