Related papers: A study of lambda Bootis type stars in the wavelen…
We present the results of a deep imaging survey of stars surrounded by planets detected with the radial velocity technique. The purpose is to search for and to characterize long-period stellar and substellar companions. The sample contains…
High-velocity stars in the Galactic halo, e.g. the so-called hyper-velocity stars (HVS), are important tracers of the properties of the dark matter halo, in particular its mass. Based on the SDSS DR6 spectral database a search for the…
We establish correlations between equivalent widths of eight diffuse interstellar bands (DIBs), and examine their correlations with atomic hydrogen, molecular hydrogen, and EB-V . The DIBs are centered at \lambda\lambda 5780.5, 6204.5,…
Based on the high resolution and high signal-to-noise spectra, we derived the chemical abundances of 20 elements for 20 barium (Ba-) stars. For the first time, the detailed abundances of four sample stars, namely HD 92482, HD 150430, HD…
We have obtained high-resolution (R $\simeq$ 50,000 or 90,000), high-quality (S/N $\ga$ 100) spectra of 22 very metal-poor stars ([Fe/H] $\la$ -2.5) with the High Dispersion Spectrograph fabricated for the 8.2m Subaru Telescope. The spectra…
HST-WFPC2 F555W and F814W photometry were obtained for 16 fields of the luminous nearby spiral galaxy M31, sampling the stellar content of the disk and the halo at different distances from the center, from ~ 20 to ~ 150 arcmin (i.e. ~ 4.5…
The Large Binocular Telescope Interferometer (LBTI) enables nulling interferometric observations across the N band (8 to 13 um) to suppress a star's bright light and probe for faint circumstellar emission. We present and statistically…
The discordance between `low' and `high' primordial D/H measurements can be considerably reduced if the analysis of the H+D profiles accounts for the correlated velocity field of bulk motion. We have re-estimated the value of D/H at z=3.572…
Debris discs are typically revealed through excess emission at infrared wavelengths. Most discs exhibit excess at mid- and far-infrared wavelengths, analogous to the solar system's Asteroid and Edgeworth-Kuiper belts. Recently, stars with…
The Beta Pictoris Moving Group is a nearby stellar association of young (12Myr) co-moving stars including the classical debris disk star beta Pictoris. Due to their proximity and youth they are excellent targets when searching for…
Extreme helium stars (EHe stars) are hydrogen-deficient supergiants of spectral type A and B. They are believed to result from mergers in double degenerate systems. In this paper we present a detailed quantitative non-LTE spectral analysis…
The southern emission-line star HD 144432 has received considerable attention due to its relative brightness (V ~ 8.17), its late spectral type (late A-type or perhaps early F) and its relative isolation from a bona-fide active star…
We present the results of ISO SWS and LWS grating scans towards the three brightest members of the BD+40 4124 group in the infrared: BD+40 4124 (B2Ve), LkHalpha 224 (A7e) and the embedded source LkHalpha 225. Emission from the pure…
We identify 20 F-type Herbig stars and provide a list of 22 pre-main-sequence candidates from LAMOST DR8. The effective temperature, distance, extinction, stellar luminosity, mass, and radius are derived for each Herbig star based on…
We present results of observations at 47 and 95 microns from the Kuiper Airborne Observatory of several ``Vega-like'' stars. Spatial cuts and aperture photometry are presented for Beta Pictoris, Fomalhaut, and HD 135344, 139614, 142527, and…
We present new high and low resolution spectroscopic and photometric data of nine members of the young association CMa R1. All the stars have circumstellar dust at some distance as could be expected from their association with reflection…
This paper presents a study of circumstellar debris around Sun-like stars using data from the Herschel DEBRIS Key Programme. DEBRIS is an unbiased survey comprising the nearest ~90 stars of each spectral type A-M. Analysis of the 275 F-K…
Blue horizontal-branch stars are Population II objects which are burning helium in their core and possess a hydrogen-burning shell and radiative envelope. Because of their low rotational velocities, diffusion has been predicted to work in…
We present results from a 2-epoch HST H$\alpha$ emission line survey of the Andromeda Galaxy that overlaps the footprint of the Panchromatic Hubble Andromeda Treasury (PHAT) survey. We find 552 (542) classical Be stars and 8429 (8556)…
We present the results of a search of infrared excess candidates in a comprehensive (29\,000 stars) magnitude limited sample of dwarf stars, spanning the spectral range F2-K0, and brighter than V$=$15 mag. We searched the sample within the…