Find Comet Lulin in Stellarium
http://www.astronomylog.co.uk/2009/02/10/find-comet-lulin-in-stellarium/ 或是看這邊
Adding Lulin to Stellarium and Celestia
http://astroblogger.blogspot.com/2009/02/adding-lulin-to-stellarium-and.html引用資料
[Lulin]
name = Lulin
parent = Sun
radius = 1000
oblateness = 0.0
halo = true
color = 1.0,1.0,1.0
tex_halo = star16×16.png
tex_map = nomap.png
coord_func = comet_orbit
orbit_TimeAtPericenter = 2454842.1414
orbit_PericenterDistance = 1.212289
orbit_Eccentricity = 0.999987
orbit_ArgOfPericenter = 136.8614
orbit_AscendingNode = 338.5353
orbit_Inclination = 178.3730
lighting = false
albedo = 1
sidereal_period =
If you want to make your own files for comets in the future, you can use the data sources I linked to in my post Making SSC Files for Celestia. Here is the data for a Lulin SSC file for Celestia. Note that it is slightly different from the Stellarium file in some items as I've used slighly different data sources.
======= 8< cut here 8< ==========================
# C/2007 N3 Lulin
"N3-Lulin" "Sol"
{
Class "comet"
Mesh "roughsphere.cms"
Texture "asteroid.jpg"
EllipticalOrbit # elements for epoch 2009
{
Epoch 2454842.115631206611 #January 14.35 2009
# Epoch is actually the Julian date of perihelion
Period 28250000 #wild guess, but it works
PericenterDistance 1.212289
Eccentricity 0.999987
Inclination 178.373
AscendingNode 338.5353
ArgOfPericenter 136.8614
MeanAnomaly 0.0
}
InfoURL "
http://cometography.com/lcomets/2007n3.html"
Radius 10.45 # Hn=12.50 Hn=14.10-2.5*log(Albedo)-5*log(Radius) Albedo=0.04
Orientation [ 90 0 0 1 ] # random value
RotationPeriod 15.613880 # random value
Obliquity 77.387310 # random value
EquatorAscendingNode 239.190649 # random value
Albedo 0.04
}
=========== 8 < cut here 8<
其他天文軟體 update comet 看這邊
http://www.cfa.harvard.edu/iau/Ephemerides/SoftwareEls.html
觀星論壇 
