Newly identified
small Solar System bodies, such as
comets and
asteroids, are given systematic designations that contain the half-month encoded as a letter of the
English alphabet.[1][2] For example, an object discovered in the second half of January would be identified with the letter B; if found in the first half of February, the letter would be C. The letter I is not used, to prevent confusion with the number 1. Instead, the letters proceed directly from H (April 16–30) to J (May 1–15). The letter appears in the
provisional designation, then when the object is confirmed the letter is incorporated into the
comet designation (for comets) or
minor planet designation (for asteroids and other
minor planets).
Newly identified
small Solar System bodies, such as
comets and
asteroids, are given systematic designations that contain the half-month encoded as a letter of the
English alphabet.[1][2] For example, an object discovered in the second half of January would be identified with the letter B; if found in the first half of February, the letter would be C. The letter I is not used, to prevent confusion with the number 1. Instead, the letters proceed directly from H (April 16–30) to J (May 1–15). The letter appears in the
provisional designation, then when the object is confirmed the letter is incorporated into the
comet designation (for comets) or
minor planet designation (for asteroids and other
minor planets).