The Carnegie Science article Solar System's Edge Redefined describes the discovery of the object 2012 VP113.

Wikipedia's article 2012 VP113 says:


2012 VP113 was abbreviated "VP" and nicknamed "Biden" by the discovery team, after Joe Biden, who at the time of discovery, was Vice President (VP) of the United States.11

11 Dwarf planet stretches Solar System's edge

and the referenced Nature News item says:

The newfound object's official name is 2012 VP113, but the discovery team calls it VP for short, or just 'Biden' — after US Vice-President Joe Biden. In several years time, after observations have pinned down its orbit, the scientists will submit a name for consideration by the International Astronomical Union (IAU), the organization in charge of celestial nomenclature.

Question: I understand that VP is short for Vice President, but where do those two letter codes come from? Is the VP in the object's name short for something literal (did the team choose these two letters?), or just a random computer-generated code, or something else?


1 Answer 1


This has to do with how minor planets obtain provisional names (see also Wikipedia). The year is divided into 24 half months, with a particular letter associated with each one. Each of these half-months has a number of cycles of length 25 depending on how many minor planets are discovered; a minor planet is assigned a letter corresponding to its order in the cycle, and the number of the cycle it is in. This means that the provisional name for a minor planet is, in general,

year+half-month+position in cycle+cycle number

2012 VP113 was discovered in 2012, in the first half-month of November (corresponding to the letter V) and was the 15th minor planet discovered in the 113th cycle that half-month.

  • $\begingroup$ Very nice, and much more complex than I expected! P is the 16th letter of the alphabet, do they skip "I" to get to 25? $\endgroup$
    – uhoh
    Dec 18, 2018 at 3:05
  • 1
    $\begingroup$ @uhoh Yes, they do. $\endgroup$
    – HDE 226868
    Dec 18, 2018 at 3:10
  • $\begingroup$ hmm... not sure why I hadn't accepted, thanks for your authoritative, concise and yet well-sourced answer! $\endgroup$
    – uhoh
    Feb 18, 2020 at 8:47

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