Comet 73P/Schwassmann-Wachmann 3 spectra


Comet 73P/Schwassmann-Wachmann 3 the 26 April 2006. Fragment C.
Canonon EOS 350D (Baader modification) + Canon EF 400 mm f/5.6 - 20 x 120 s @ ISO400

Fragment C - May 11.10 UT, 2006

Fast movement of 73P/Schwassmann-Wachmann 3 captured with the guiding camera
of LHIRES III spectrograph at the focus of the Celestron 11 (Watek 120N - exposure 2.56 s).
The comet nucleus is positioned on the entrance slit of the spectrograph (the horizontal dark line - 20 microns wide).
Automatic autoguiding on the comet with Iris software..


2H01 UT
 


2H10 UT
 


2H19 UT
 


2D spectrum of 73P-C/SW3 before sky removal
(high pressure sodium pollution light).
Celestron 11 + Lhires III #76 spectrograph (first light!)
CCD camera Audine KAF-0402ME - Bin 2x2
Grating 150 groove/mm - Spectral sampling of 5.9 A/pixel
Total exposure time of 10 x 300 s the 10.10/05/2006


2D spectrum of 73P-C/SW3 after sky removal.
Note the [0I] comet line (yellow line at 6300 A).
The comet is very dusty (nothing about C2 emission).


2D spectrum of the solar type star HD217014 observed the same night.

 
Observed spectral profile of Comet 73P/Schwassmann-Wachmann 3 (fragment C).
The instrumental responsivity of the instrument is not removed


A first checking star: HD197076 (solar analog star).
 


 A second checking star: HD217014 (solar analog star).
 


Ratio of the SW3 spectrum and of th HD197076 spectrum.
Dust reddening of the comet is evident (nearly no trace
of gazes at the time of observation).


Ratio of the SW3 spectrum and of th HD217014 spectrum.
Note the comet's [OI] glow line.


Check of the ratio consistency.

Fragment B - May 12.97 UT, 2006

Fast movement of 73P/Schwassmann-Wachmann 3 captured with the g


LHIRES III guide camera image of fragment B (expo. 5.12 s). Large and diffuse aspect (no trace of bright nucleus).


2D spectrum before sky background removal.
Exposure: 6 x 300 s (clouds arrival impose to stop the observation)


2D spectrum after background removal.
Note the wide trace spectrum.


Observed spectral profile. The instrumental response is not taken into account.
 


Reflectance spectrum of SW3-B. [OI] line is visible at 6300 A, but no clear evidence of C2 swan bands at the observed signal to noise ratio.

Fragments B, C, G the 23 April 2006.
(see also here)

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