Are There Planets around the Pulsar PSR B0329+54?

Abstract

Using the pulse arrival time measurements of the pulsar PSR B032954 made between 1994 and 1998 with the 100 m Effelsberg and the 32 m Torun´radioTorun´Torun´radio telescopes supplemented with the archival JPL data, we demonstrate that the planets suggested to orbit this yr old object are unlikely to be real. The previously proposed 6 ∼ 5 # 10 timing models, including 3 and 16.8 yr orbits of terrestrial-mass planets, fail to predict the pulse arrival times at later epochs. If this pulsar has planetary companions, the remaining possibilities include low-mass objects that are below the current detection threshold, multiple terrestrial-mass planets in orbits whose superposition could produce the timing noiselike effects, and any planets with orbital periods significantly exceeding the 30 yr data span. However, it is likely that the observed variations in timing residuals of PSR B032954 are caused by spin irregularities that are intrinsic to this relatively young neutron star.