Related papers: Characterization of K2-167 b and CALM, a new stell…
HD 21749 is a bright ($V=8.1$ mag) K dwarf at 16 pc known to host an inner terrestrial planet HD 21749c as well as an outer sub-Neptune HD 21749b, both delivered by TESS. Follow-up spectroscopic observations measured the mass of HD 21749b…
This paper reports on the validation and mass measurement of K2-263b, a sub-Neptune orbiting a quiet G9V star. Using K2 data from campaigns C5 and C16, we find this planet to have a period of $50.818947\pm 0.000094$ days and a radius of…
We report the discovery of HATS-2b, the second transiting extrasolar planet detected by the HATSouth survey. HATS-2b is moving on a circular orbit around a V=13.6 mag, K-type dwarf star (GSC 6665-00236), at a separation of 0.0230 \pm 0.0003…
We present a comprehensive analysis of 10 years of HARPS radial velocities of the K2V dwarf star HD 13808, which has previously been reported to host two unconfirmed planet candidates. We use the state-of-the-art nested sampling algorithm…
We present a new analysis of Kepler-21, the brightest (V = 8.5) Kepler system with a known transiting exoplanet, Kepler-21 b. Kepler-21 b is a radius valley planet ($R = 1.6\pm 0.2 R_{\oplus}$) with an Earth-like composition (8.38$\pm$1.62…
Stellar activity is the main limitation to the detection of Earth-twins using the RV technique. Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are…
Stellar activity is the ultimate source of radial-velocity (RV) noise in the search for Earth-mass planets orbiting late-type main-sequence stars. We analyse the performance of four different indicators and the chromospheric index $\log…
We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1-dwarf with high proper motion, and a parallax-based distance of 55.2 +/- 5.4 pc. Based…
We combine multiple campaigns of K2 photometry with precision radial velocity measurements from Keck-HIRES to measure the masses of three sub-Neptune-size planets. We confirm the planetary nature of the massive sub-Neptune K2-182 b…
One of the best ways to improve our understanding of the stellar activity-induced signal in radial velocity (RV) measurements is through simultaneous high-precision photometric and RV observations. This is of prime importance to mitigate…
Accurate mass and radius measurements of small transiting exoplanets are essential for probing their compositions, formation histories, and potential habitability. We present a uniform analysis of six planetary systems (each hosting at…
We present an analysis of the publicly available HARPS radial velocity (RV) measurements for Alpha Cen B, a star hosting an Earth-mass planet candidate in a 3.24 day orbit. The goal is to devise robust ways of extracting low-amplitude RV…
In the framework of the Global Architecture of Planetary Systems (GAPS) project we collected more than 300 spectra with HARPS-N at the TNG for the bright G9V star HD164922. This target is known to host one gas giant planet in a wide orbit…
We report the discovery from K2 of a transiting terrestrial planet in an ultra-short-period orbit around an M3-dwarf. K2-137 b completes an orbit in only 4.3 hours, the second-shortest orbital period of any known planet, just 4 minutes…
K2-146 is a mid-M dwarf ($M_\star = 0.331 \pm 0.009 M_\odot$; $R_\star = 0.330 \pm 0.010 R_\odot$), observed in Campaigns 5, 16, and 18 of the K2 mission. In Campaign 5 data, a single planet was discovered with an orbital period of…
In an earlier campaign to characterize the mass of the transiting temperate super-Earth K2-18b with HARPS, a second, non-transiting planet was posited to exist in the system at $\sim 9$ days. Further radial velocity follow-up with the…
We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 ($V = 8.9$ mag, $M = 0.58 \pm 0.08$ M$_{\odot}$), a bright…
The bright M dwarf K2-18 at 34 pc is known to host a transiting super-Earth-sized planet orbiting within the star's habitable zone; K2-18b. Given the superlative nature of this system for studying an exoplanetary atmosphere receiving…
HD3167 is a bright (V=8.9 mag) K0V star observed by the NASA's K2 space mission during its Campaign 8. It has been recently found to host two small transiting planets, namely, HD3167b, an ultra short period (0.96 d) super-Earth, and…
The HARPS high-resolution high-accuracy spectrograph is offered to the astronomical community since the second half of 2003. Since then, we have been using this instrument for monitoring radial velocities of a large sample of Solar-type…