[Kstars-devel] New minor planet

[Jason Harris]

Update:

There were actually two minor planets announced today: 2003 EL61 and 2003 
UB313.  EL61 is estimated to be somewhat smaller than Pluto, and lies about 
25% further away from the Sun than Pluto.  UB313 is almost certainly larger 
than Pluto, and it is currently twice as far from the Sun as Pluto.
The MPEC page for UB313 is here:
http://cfa-www.harvard.edu/mpec/K05/K05O41.html

My constructed elements line for UB313 is:
99998 2003 UB313        53600 67.7091000 0.4416129   44.17700 151.31153  
35.87500 197.53790   -1.1

However, once again the position in KStars seems to be in error.  It's not as 
far off as EL61, but it's still wrong by tens of arcminutes.  Still don't 
understand what the problem is.  Still waiting for the JPL page to add these 
objects.

Jason


On Friday 29 July 2005 10:39 am, Jason Harris wrote:
> 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

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