Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary★†

Abstract

We report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V ∼ 10). WASP-69b is a bloated Saturn-mass planet (0.26 M Jup , 1.06 R Jup ) in a 3.868-d period around an active, ∼1-Gyr, mid-K dwarf. ROSAT detected X-rays 60±27 ′′ from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ∼10 12 g s −1 . This is 1-2 orders of magnitude higher than the evaporation rate estimated for HD 209458b and HD 189733b, both of which have exhibited anomalously-large Lyman-α absorption during transit. WASP-70Ab is a sub-Jupiter-mass planet (0.59 M Jup , 1.16 R Jup ) in a 3.713-d orbit around the primary of a spatially-resolved, 9-10-Gyr, G4+K3 binary, with a separation of 3. ′′ 3 ( 800 AU). WASP-84b is a sub-Jupiter-mass planet (0.69 M Jup , 0.94 R Jup ) in an 8.523-d orbit around an active, ∼1-Gyr, early-K dwarf. Of the transiting planets discovered from the ground to date, WASP-84b has the third-longest period. For the active stars WASP-69 and WASP-84, we pre-whitened the radial velocities using a low-order harmonic series. We found this reduced the residual scatter more than did the oft-used method of pre-whitening with a fit between residual radial velocity and bisector span. The system parameters were essentially unaffected by pre-whitening. -planets and satellites: individual: WASP-69b -planets and satellites: individual: WASP-70Ab -planets and satellites: individual: WASP-84b.⋆ Based on observations made with the WASP-South (South Africa) and SuperWASP-North (La Palma) photometric survey instruments, the RISE camera on the 2-m Liverpool Telescope under program PL12B13, and, all located at La Silla: the 60-cm TRAPPIST photometer, EulerCam and the CORALIE spectrograph, both mounted on the 1.2-m Euler-Swiss telescope, and the HARPS spectrograph on the ESO 3.6-m telescope under program 89.C-0151.† The photometric time-series and radial-velocity data used in this work are available at the CDS via anony-

The discoveries of WASP-91b, WASP-105b and WASP-107b: Two warm Jupiters and a planet in the transition region between ice giants and gas giants

“…Finally, WASP-107b is a 0.12-M Jup planet in a 5.7-day orbit around a K6 star. Together with WASP-139b (M P = 0.12 ± 0.02 M Jup ; Hellier et al 2016), WASP-107b is the lowest-mass planet discovered by WASP to date; the next lowest are WASP-29b (0.24 M Jup ; Hellier et al 2010) and WASP-69b (0.26 M Jup ; Anderson et al 2014). Giant planets seem to be more common around both stars of higher metallicity and stars of higher mass (e.g.…”

“…For example, WASP-84b is in a relatively wide orbit around a young star, indicating that it has experienced relatively weak tidal forcing over a short duration. Therefore, its near-circular and near-aligned orbit is suggestive of disc migration (Anderson et al 2014(Anderson et al , 2015b. Further, WASP-47 comprises a hot Jupiter, a nearby super-Earth, a nearby Neptune, and a more distant Jupiter.…”

The SOPHIE search for northern extrasolar planets

“…Only a few planetary systems are known around stars with log R HK > −4.5. They include hot Jupiters such as WASP-52b, 59b, or 84b Anderson et al 2014), giant planets on longer periods such as HD 192263b, GJ 3021b, and HD 81040b (Santos et al 2000a;Naef et al 2001;Sozzetti et al 2006), or the multi-planet systems around HD 128311 and HD 9446 (Vogt et al 2005;Hébrard et al 2010). The new giant planet HD 12484b increases this population.…”

THREE WASP-SOUTH TRANSITING EXOPLANETS: WASP-74b, WASP-83b, AND WASP-89b

“…The observational and analysis techniques used here are similar to those in recent WASP-South discovery papers (e.g., Hellier et al 2012;Anderson et al 2014), and so are reported briefly. WASP-South surveys the southern sky using an array of 200 mm f/1.8 lenses and a cadence of ∼10 minutes (see Pollacco et al 2006).…”