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 |
|
|
|
|
<2 |
|
C/2008 T2 (Cardinal) |
13.6.2009 |
v.P. |
8.6 |
|
C/2006 W3 (Christensen) |
6.7.2009 |
v.P. |
6.8 |
41
|
|
|
|
8.6 |
|
88P/Howell |
13.10.2009 |
v.P. |
>10 |
|
103P/Hartley |
28.10.2010 |
v.P.
|
10.0
|
0.39
|
|
|
n.P.
|
2.2
|
|
(v.P. = before perihel, n.P. = after perihel)