WASP-42 is a K-type main-sequence star. Its surface temperature is 5315 K.[1] WASP-42 is similar to the Sun in concentration of heavy elements, with metallicity ([Fe/H]) of 0.05, and is much older than the Sun at billion years. The star does exhibit starspot activity as is typical for its spectral class.
Multiplicity surveys did not detect any stellar companions to WASP-42 in 2017.
In 2012, one planet, named WASP-42b, was discovered on a tight, mildly eccentric orbit. The planetary equilibrium temperature is 1021 K.