Gas production and chemical composition of selected comets

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Walter Hübner wrote 1965 this article, which gives a theory for calculating the gas production of comets. It is applicable to such comets which could be observed over a long way through the solar system. It is possible to calculate the gas production per surface unit and the vaporization heat. The vaporization heat L is of special interest, because it gives a link to the composition of comets and for the process of vaporization or sublimation.

The article is in German. To support understanding this work I translated a lecture I hold into English. This lecture was hold during the meeting of the German comet observers' group in 2009. The symbols are equal to the Hübners'. Some images contain German words, sorry for that.

Walter Hübner could and did not use computers for his calculation. He used a graphical method instead. I write a computer program for calculating the values which uses the method of least squares.

Results until  November 2009

The following table contains the results of my simulations. In some cases I could calculate the diameter of the comets' active (gas evolving) area A. Therefore I need the total gas production at least for one time. Such results are received from spectroscopic measurements.
If you click at the vaporization heat L you get a graphic which compares the calculated and simulated gas production with changing solar distance. It shows the deviations which are based on the uncertainties of our observations and can give an idea for the reliability of the results.

Comet Date of perihel v.P. / n.P. L: kcal/mol A: km2
C/2006 P1 (McNaught) 12.1.2007 v.P. >10

n.P 9.1 3.8
8P/Tuttle 27.1.2008 v.P >10 1.8

n.P. 11
C/2007 N3 (Lulin) 10.1.2009 v.P. 7.8

n.P. 2.3 1.3
22P/Kopff 25.5.2009 v.P. 9.5

C/2008 T2 (Cardinal) 13.6.2009 v.P. 8.6
C/2006 W3 (Christensen) 6.7.2009 v.P. 6.8 41

88P/Howell 13.10.2009 v.P. >10
103P/Hartley 28.10.2010 v.P.


(v.P. = before perihel, n.P. = after perihel)