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C/2006 A1 "calc"
Posted: 26.02.2006, 00:38
by symaski62
Code: Select all
"C/2006 A1" "Sol"
{
Class "comet"
Texture "asteroid.jpg"
Mesh "asteroid.cms"
Radius 5
EllipticalOrbit
{
Period ???? #calculated: (q/(1-e))^1.5
PericenterDistance 0.555405007052757
Eccentricity 1
Inclination 92.7398026068976
AscendingNode 211.341862238783
ArgOfPericenter 351.18629543621
MeanAnomaly 0.0
Epoch 2453754.5
}
}#calculated: (q/(1-e))^1.5
?!?
Posted: 26.02.2006, 03:38
by GlobeMaker
Posted: 26.02.2006, 04:05
by symaski62
GlobeMaker wrote:http://www.lns.cornell.edu/~seb/celestia/orbital-parameters.html
q pericenter
e eccentricity
1.5 = 3/2
pericenter 0.5554
eccentricity 1
(0.5554/(1-1))^1.5 = 0
Posted: 26.02.2006, 04:36
by GlobeMaker
A parabola has an eccentricity of 1.
Posted: 02.03.2006, 11:14
by Adirondack
In other words:
If eccentricity = or > 1 the comet will never come back, so there is no period!
Posted: 02.03.2006, 13:02
by selden
Celestia requires that you specify a Period.
# For a closed, elliptical solar orbit,
P = sqrt (( q / ( 1 - e)) ^3)
or = a^1.5
P = 1/n = 1/ Mean Motion
For an open, hyperbolic orbit, one can use
P = sqrt (( q / ( e - 1)) ^3)
where P is the period measured in years
q is the pericenter measured in AU
e is the eccentricity
and a is the semimajor axis of the orbit, also measured in AU (which has a negative value for hyperbolic orbits).
Thanks to Grant Hutchison for explaining this.