Related papers: A search for planets in the metal-enriched binary …
(abridged) Search for planets around main-sequence (MS) stars more massive than the Sun is hindered by their hot and rapidly spinning atmospheres. This obstacle has been sidestepped by radial-velocity surveys of those stars on their post-MS…
We report the discovery and validation of HD 21520 b, a transiting planet found with TESS and orbiting a bright G dwarf (V=9.2, $T_{eff} = 5871 \pm 62$ K, $R_{\star} = 1.04\pm 0.02\, R_{\odot}$). HD 21520 b was originally alerted as a…
The G0V star HD166435 has been observed by the fiber-fed spectrograph ELODIE as one of the targets in the large extra-solar planet survey that we are conducting at the Observatory of Haute-Provence. We detected coherent, low-amplitude,…
We have derived elemental abundances of a remarkable star, HD 179821, with unusual composition (e.g. [Na/Fe]=1.0$\pm$0.2 dex) and extra-ordinary spectral characteristics. Its metallicity at [Fe/H]=0.4 dex places it among the most metal-rich…
Aims: To determine the metallicities of 113 Southern Hemisphere Vega-like candidate stars in relation to the Exoplanet host group and field stars. Methods: We applied two spectroscopic methods of abundance determinations: equivalent width…
Context: For over 12 yr, we have carried out a precise radial velocity survey of a sample of 373 G and K giant stars using the Hamilton \'Echelle Spectrograph at Lick Observatory. There are, among others, a number of multiple planetary…
We monitored three transits of the giant gas planet around the nearby K dwarf HD 189733 with the ACS camera on the Hubble Space Telescope. The resulting very-high accuracy lightcurve (signal-to-noise ratio near 15000 on individual…
Stars in their late stage of evolution, such as Horizontal Branch stars, are still largely unexplored for planets. We report the detection of a planetary companion around HIP 13044, a very metal-poor star on the red Horizontal Branch, based…
Statistical studies of exoplanets have shown that giant planets are more commonly hosted by metal-rich dwarf stars than low-metallicity ones, while such a correlation is not evident for lower-mass planets. The search for giant planets…
We present new results from a study of high quality, red spectra of the massive binary star system HD 1383 (B0.5 Ib + B0.5 Ib). We determined radial velocities and revised orbital elements (P = 20.28184 +/- 0.0002 d) and made Doppler…
New spectroscopic observations of the halo hyper-velocity star candidate SDSS J121150.27+143716.2 ($V=17.92$ mag) revealed a cool companion to the hot subdwarf primary. The components have a very similar radial velocity and their absolute…
Stellar metallicity strongly correlates with the presence of planets and their properties. To check for new correlations between stars and the existence of an orbiting planet, we determine precise stellar parameters for a sample of…
We report the detection of a large sample of high-$\alpha$-metal-rich stars on the low giant branch with $2.6<logg<3.3$ dex in the LAMOST-MRS survey. This special group corresponds to an intermediate-age population of $5-9$ Gyr based on the…
We present new, high-precision Doppler radial velocity (RV) data sets for the nearby K3V star HD 219134. The data include 175 velocities obtained with the HIRES Spectrograph at the Keck I Telescope, and 101 velocities obtained with the Levy…
The spectroscopic orbit of a high proper motion visual binary system BD +30 2129 component A is determined from 22 CORAVEL-type radial velocity measurements. A period of P = 32.79 days and a moderate eccentricity e = 0.29 are obtained. The…
HD66051 is an eclipsing system with an orbital period of about 4.75 d that exhibits out-of-eclipse variability with the same period. New multicolour photometric observations confirm the longevity of the secondary variations, which we…
We report the detection of five Jovian mass planets orbiting high metallicity stars. Four of these stars were first observed as part of the N2K program and exhibited low RMS velocity scatter after three consecutive observations. However,…
We confirm the planetary nature of TOI-5344 b as a transiting giant exoplanet around an M0 dwarf star. TOI-5344 b was discovered with the Transiting Exoplanet Survey Satellite photometry and confirmed with ground-based photometry (the Red…
For the past 3 years we have been monitoring 62 K giant stars using precise stellar radial velocity (RV) measurements with the 2m Alfred Jensch telescope of the Th\"uringer Landessternwarte Tautenburg (TLS). To probe the dependence of…
One important property in studying the exoplanet population is the host star metallicity ([M/H]). In this study, we derived stellar metallicities and oxygen abundances for 48 M dwarf stars using the near-infrared high-resolution spectra…