An Etymological Dictionary of Astronomy and Astrophysics

A phenomenon in which the rotation period of a pulsar steadily decreases with the pulsar age. The cause of the spin-down is magnetic torque due to the strong fields threading out from the pulsar. The magnetic energy is being converted to high-energy particles and radiation from the nebula. Observed spin-down rates range from about 10^-5 seconds/year for the youngest pulsars to about 10^-12 seconds/year for recycled pulsars. The Crab pulsar is slowing down at a rate of about 10^-5 seconds/year. Knowing the rotation period and the lengthening rate of a pulsar leads to its age.

Etymology (EN): → spin; down, M.E.; O.E. ofdune “downward,” from dune “from the hill.”

Etymology (PE): Kond-carxi, from kond “slow; dull” + carx→ rotate + -i noun suffix.