[Kstars-devel] New minor planet

[Jason Harris]

Hello,

I read about a new planet discovery beyond Pluto: 2003 EL61.  This one may 
turn out to be larger than Pluto!

I tried to add it to KStars this morning, using the orbital elements published 
in the "Minor Planets Electronics Circular" here:
http://cfa-www.harvard.edu/mpec/K05/K05O36.html

However, the position of the object in KStars is about 2 degrees away from the 
position listed for today on that page (the error appears to be along the 
ecliptic latitude direction).   The NASA/JPL webpage where I usually get 
orbital elements doesn't yet include this object.

The line I constructed from the MPEC page is:
99999 2003 EL61         53600 43.3391124 0.1888463   28.19471 239.51228 
121.89507 198.07463    0.4

(the columns are: ID, Name, modified JD, semimajor axis (AU), eccentricity, 
inclination, long. of perihelion, long. of ascending node, Mean anomaly, and 
H (mag) )

I checked the position of some other objects in KStars against the MPEC 
ephemerides, and they appear to be Ok.  

At this point, I'm not sure what the problem is.  It could be that the orbit 
is still immature, so it doesn't match the current observations yet.  
However, 2 degrees strikes me as way too large for this explanation.  I 
thought that perhaps the particular definition of one or more of the elements 
might be slightly different between the MPEC and the JPL publication.  
However, I have checked the definitions, and they appear to be the same.

I'm not going to commit the elements right away.  If anyone wants to check my 
line against the MPEC page, please feel free.  I have triple-checked (twice!) 
already though :).  I'll keep trying the JPL page; hopefully it will be 
updated soon.

Jason
-- 
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KStars: KDE Desktop Planetarium
http://edu.kde.org/kstars