[meteorite-list] 2003 UB313 Update

[Ron Baalke]

http://www.gps.caltech.edu/~mbrown/planetlila/index.html

2003 UB313 Update
Mike Brown

Update on the name on status

We have recently discussed the status of the object and of the name 
with members of the IAU who decide such things. As far as we can 
determine several activities are taking place:

    * A special committee of the International Astronomical Union (IAU)
      is trying to decide precisely what to classify this as.
    * Another committee of the IAU which vets names for asteroids and 
      Kuiper belt objects is mulling over the name that we suggested 
      upon discovery.
    * Yet another committee of the IAU which approves names for 
      features on major planets and satellites has suggested that if 
      the object is declared a major planet the naming falls strictly 
      to them, and they have suggested that the name should continue 
      the Greco-Roman tradition of the previous planets. We have a 
      couple of interesting choices in mind in that case.

It appears that with the dead  month of August rolling around no one 
will be making decision anytime soon, though the IAU has recently 
made an official pronouncement (http://www.iau.org/IAU/FAQ/2003_UB313.html)


Update on upcoming Spitzer observations

Though we tried earlier to measure the size using Spitzer, those 
observations failed due to human error which caused the telescope 
to point in the wrong direction. The Spitzer Space Telescope rarely 
makes such errors, but these observations were extremely unusual in 
that they were of a moving object whose position could not be 
obtained from pubically available web sites at JPL (since JPL didn't 
yet know of the existence of the object). Instead, a string of human 
interaction had to occur between our [correct] submission of the 
orbital elements and the final pointing of the telescope. Somewhere 
in this string of interactions a mistake was made. Two other Kuiper 
belt objects (2003 EL61 and 2005 FY9) were observed in the same manner 
at the same time and the observations proceeded without a glitch, 
leading us to initially assume that the 2003 UB313 observations were 
correctly pointed also. The mistake was caught by one of the many 
extremely careful members of the Spitzer Science Center. As soon as 
the mistake was caught new observations were scheduled and safeguards 
were put into place to prevent such an occurence again. Spitzer will 
again attempt to observe 2003 UB313 at the end of the month.

In the meantime, we are attempting observing from the 30-meter IRAM 
telescope. This telescope, like Spitzer, measures the heat output. 
But IRAM measures the heat output in a region of the spectrum where 
much less heat is output. Nonetheless we have high hopes that these 
observations will succeed. The combination of Spitzer and IRAM will 
be especially powerful.

Yet another step to try to measure the size will be to observe the 
planet with the Hubble Space Telescope and see if we can do some very 
careful analysis to measure the size in a similar manner as we did 
for the planetoid Quaoar. These observations are already scheduled 
and will be taking place shortly, though the observations are 
optimzed for detection of satellite rather than size measurement. 
We are attempting to secure observations optimized for size 
measurement.