相关论文: M Dwarf Exoplanet Surface Density Distribution: A …

We show that the astrometric Hipparcos data of the stars hosting planet candidates are not accurate enough to yield statistically significant orbits. Therefore, the recent suggestion, based on the analysis of the Hipparcos data, that the…

We report precise Doppler measurements of GJ317 (M3.5V) that reveal the presence of a planet with a minimum mass Msini = 1.2 Mjup in an eccentric, 692.9 day orbit. GJ317 is only the third M dwarf with a Doppler-detected Jovian planet. The…

The surface density and vertical distribution of stars, stellar remnants, and gas in the solar vicinity form important ingredients for understanding the star formation history of the Galaxy as well as for inferring the local density of dark…

The orbital distribution of giant planets is crucial for understanding how terrestrial planets form and predicting yields of exoplanet surveys. Here, we derive giant planets occurrence rates as a function of orbital period by taking into…

We investigate the stellar metallicity ([Fe/H] and [M/H]) dependence of giant planets around M dwarfs by comparing the metallicity distribution of 746 field M dwarfs without known giant planets with a sample of 22 M dwarfs hosting confirmed…

We propose a near-infrared microlensing survey of the central 2 degree field of the Galactic Center, in an attempt to estimate the surface density and mass distribution of distant free-floating brown dwarfs in the bulge and in the disk,…

Future NASA concept missions that are currently under study, like Habitable Exoplanet Imaging Mission (HabEx) & Large Ultra-Violet Optical Infra Red (LUVOIR) Surveyor, would discover a large diversity of exoplanets. We propose here a…

The distribution of dark matter in dwarf galaxies can have important implications on our understanding of galaxy formation as well as the particle physics properties of dark matter. However, accurately characterizing the dark matter content…

The surface gravities of cool (Teff < 13,000 K) hydrogen-atmosphere DA white dwarfs, determined from spectroscopic analyses, are found to be significantly higher than the canonical value of log g ~ 8 expected for these stars. It was…

We present the results from a five-year campaign to gather multi-epoch, high-resolution spectra of a volume-complete sample of 413 M dwarfs with masses 10-30% that of the Sun that lie within 15 parsecs. We report weighted mean systemic…

Fewer giants planets are found around M dwarfs than around more massive stars, and this dependence of planetary characteristics on the mass of the central star is an important observational diagnostic of planetary formation theories. In…

The planet formation environment around M dwarf stars is different than around G dwarf stars. The longer hot protostellar phase, activity levels and lower protoplanetary disk mass of M dwarfs all may leave imprints on the composition…

We construct mass models of eight gas rich dwarf galaxies that lie in the Lynx-Cancer void. From NFW fits to the dark matter halo profile, we find that the concentration parameters of halos of void dwarf galaxies are similar to those of…

Analysis of initial observations from near-infrared sky surveys has shown that the resulting photometric catalogues, combined with far-red optical data, provide an extremely effective method of finding isolated, very low-temperature objects…

We present statistical results from the Epoch of Giant Planet Migration RV planet search program. This survey was designed to measure the occurrence rate of giant planets interior to the water ice line of young Sun-like stars, compare this…

Terrestrial planets are commonly observed to orbit M dwarfs with close-in trajectories. In this work, we extensively perform N-body simulations of planetesimal accretion with three models of in-situ, inward migration and reversed migration…

We present a new estimate for the binary fraction (the fraction of stars with a single companion) for M dwarfs using a log-normal fit to the orbital separation distribution. We use point estimates of the binary fraction (binary fractions…

Context: Around 30 per cent of the observed exoplanets that orbit M dwarf stars are gas giants that are more massive than Jupiter. These planets are prime candidates for formation by disc instability. Aims: We want to determine the…

We re-determine planetary occurrences around M dwarfs using 20 years of observations from HARPS on 197 targets. The first aim of this study is to propose more precise occurrence rates using the large volume of the sample but also variations…

We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. But the detailed light curve…