Related papers: Aliases of the first eccentric harmonic : Is GJ 58…
Radial velocity measurements of stellar reflex motion have revealed many extrasolar planets, but gaps in the observations produce aliases, spurious frequencies that are frequently confused with the planets' orbital frequencies. In the case…
Based on two decades of radial velocity (RV) observations using Keck/HIRES and McDonald/Tull, and more recent observations using the Automated Planet Finder, we found that the nearby star HR 5183 (HD 120066) hosts a 3$M_J$ minimum mass…
We present an analysis of the significantly expanded HARPS 2011 radial velocity data set for GJ 581 that was presented by Forveille et al. (2011). Our analysis reaches substantially different conclusions regarding the evidence for a…
We investigate the radial velocity variation of GJ 581 based on measurements from the HARPS and Keck HIRES spectrographs. A Fourier pre-whitening procedure is able to extract four planetary signals in the HARPS data and two from the Keck…
The four-planet system around GJ 581 has received attention because it has been claimed that there are possibly two additional low-mass companions as well - one of them being a planet in the middle of the stellar habitable zone. We…
We present 11 years of HIRES precision radial velocities (RV) of the nearby M3V star Gliese 581, combining our data set of 122 precision RVs with an existing published 4.3-year set of 119 HARPS precision RVs. The velocity set now indicates…
GJ 581d is a potentially habitable super-Earth in the multiple system of exoplanets orbiting a nearby M dwarf. We investigate this planet's long-term dynamics, with an emphasis on its probable final rotation states acquired via tidal…
The GJ 581 system has been amply studied since its discovery in 2005: the number of known planets in the system has increased and their orbital parameters are among the most precisely determined for radial velocity detected exoplanets. We…
GJ 581 is a nearby M dwarf known to host a packed multiple planet system with 2 super-Earths and a Neptune-mass planet. We present new orbital analyses of the system, utilizing recent RV data obtained from the CARMENES spectrograph combined…
The interaction between Earth-like exoplanets and the magnetic field of low-mass host stars are considered to produce weak emission signals at radio frequencies. A study using LOFAR data announced the detection of radio emission from the…
The M dwarf Gliese 581 is believed to host four planets, including one (GJ 581d) near the habitable zone that could possibly support liquid water on its surface if it is a rocky planet. The detection of another habitable-zone planet--GJ…
GJ667C is the least massive component of a triple star system which lies at a distance of about 6.8 pc (22.1 light-years) from Earth. GJ667C has received much attention recently due to the claims that it hosts up to seven planets including…
The role of radial velocity (RV) jitter in extrasolar planet search surveys is discussed. Based on the maximum likelihood principle, improved statistical algorithms for RV fitting and period search are developed. These algorithms…
The Gliese 581 planetary system has received attention because it has been proposed to host a low-mass planet in its habitable zone. We re-analyse the radial velocity measurements reported to contain six planetary signals to see whether…
We have done a new analysis of the available observations for the GJ581 exoplanetary system. Today this system is controversial due to choices that can be done in the orbital determination. The main ones are the ocurrence of aliases and the…
We report the detection of a Neptune-mass exoplanet around the M4.0 dwarf GJ 4276 (G 232-070) based on radial velocity (RV) observations obtained with the CARMENES spectrograph. The RV variations of GJ 4276 are best explained by the…
The GJ 581 planetary system was already known to harbour three planets, including two super-Earths planets which straddle its habitable zone. We report here the detection of an additional planet -- GJ 581e -- with a minimum mass of 1.9…
Detecting a planetary companion in a short-period orbit through radio emission from the interaction with its host star is a new prospect in exoplanet science. Recently, a tantalising signal was found close to the low-mass stellar system GJ…
Context. GJ 581, an M3 dwarf, hosts a rich system of exo-planets, some of which are potentially within or at the edge of the Habitable Zone. Nevertheless the system habitability might be reduced by large and sterilizing high energy emission…
We perform a detailed analysis of the latest HARPS and Keck radial velocity data for the planet-hosting red dwarf GJ581, which attracted a lot of attention in recent time. We show that these data contain important correlated noise component…