We present here the discovery and characterisation of a very light planet around HD 4308. The planet orbits its star in 15.56 days. The circular radial-velocity variation presents a tiny semi-amplitude of 4.1 ms−1 that corresponds to a planetary minimum mass m2 sin i= 14.1 M⊕ (Earth masses). The planet was unveiled by high-precision radial-velocity measurements obtained with the HARPS spectrogr...

The bright F8 V star t Andromedae was previously reported to have a 4.6 day Doppler velocity periodicity, consistent with having a Jupiter-mass companion orbiting at 0.059 AU. Follow-up observations by both the Lick and Advanced Fiber-Optic Echelle spectrometer (AFOE) planet survey programs conÐrm this periodicity and reveal additional periodicities at 241 and 1267 days. These periodicities are...

Much effort has been invested in recent years, both observationally and theoretically, to understand the interacting processes taking place in planetary systems consisting of a hot Jupiter orbiting its star within 10 stellar radii. Several independent studies have converged on the same scenario: that a short-period planet can induce activity on the photosphere and upper atmosphere of its host s...

High-precision radial velocity planet searches have surveyed ∼2000 nearby stars and detected ∼130 planets. While these same stars likely harbor many additional planets, they will become increasingly challenging to detect, as they tend to have relatively small masses and/or relatively long orbital periods. Therefore, observers are increasing the precision of their observations, continuing to mon...

We propose that the eccentricity and sharpness of the edge of Fomalhaut’s disk are due to a planet just interior to the ring edge. The collision timescale consistent with the disk opacity is long enough that spiral density waves cannot be driven near the planet. The ring edge is likely to be located at the boundary of a chaotic zone in the corotation region of the planet. We find that this zone...

We consider the high eccentricity, 0.66, of the newly discovered planet around 16 Cyg B, using the fact that the parent star is part of a wide binary. We show that the high eccentricity of the planet could be the result of tidal forces exerted on 16 Cyg B and its planet by 16 Cyg A, the distant companion in the system. By following stellar triple systems with parameters similar to those of 16 C...

We provide updates to the Kepler planet candidate sample based upon nearly two years of high-precision photometry (i.e., Q1–Q8). From an initial list of nearly 13,400 threshold crossing events, 480 new host stars are identified from their flux time series as consistent with hosting transiting planets. Potential transit signals are subjected to further analysis using the pixel-level data, which ...

We investigate the effect of the viscosity on disk-planet interaction and type I migration of planets. We have performed a linear calculation using shearingsheet approximation and obtained the detailed, high resolution density structure around the planet embedded in a viscous disk with a wide range of viscous coefficients. We find that the density structure in the vicinity of the resonance is m...

Results are presented from a new algorithm developed for separating the vibration signals from a planetary gear system into separate signals attributable to each planet gear. From the separate signals, time synchronous average signals are produced for each planet gear and for the sun gear meshing with each planet gear. Assessments of the individual planet and sun gears can be made from these ne...

Doppler measurements of the M4 dwarf star, Gliese 876, taken at both Lick and Keck Observatory reveal periodic, Keplerian velocity variations with a period of 61 days. The orbital fit implies that the companion has a mass of, M = 2.1 MJUP/ sin i, an orbital eccentricity of, e = 0.27±0.03, and a semimajor axis of, a = 0.21 AU. The planet is the first found around an M dwarf, and was drawn from a...