  First identified from the HATNet wide-field photometric survey, these
candidate transiting planets were then followed-up with a variety of
photometric observations. Determining the planetary nature of the objects and
characterizing the parameters of the systems were mainly done with the SOPHIE
spectrograph at the 1.93m telescope at OHP and the TRES spectrograph at the
1.5m telescope at FLWO. HAT-P-42b and HAT-P-43b are typical hot Jupiters on
circular orbits around early-G/late-F main sequence host stars, with periods of
4.641876\pm0.000032 and 3.332688\pm0.000016 days, masses of 0.975\pm0.126 and
0.660\pm0.083 Mjup, and radii of 1.277\pm0.149 and 1.283+0.057-0.034 Rjup,
respectively. These discoveries increase the sample of planets with measured
mean densities, which is needed to constrain theories of planetary interiors
and atmospheres. Moreover, their hosts are relatively bright (V < 13.5)
facilitating further follow-up studies.
