84 datasets found

Two years of Kepler data are used to investigate low-frequency variations in A-type stars. In about 875 (40%) A-type stars, the periodogram shows a simple peak and its harmonic....

We present coordinates and available photometric information (either from previous or recent broadband UBV observations, and near-infrared photometry from the 2MASS Point Source...

The first directly imaged exoplanets indicated that wide-orbit giant planets could be more common around A-type stars. However, the relatively small number of nearby A-stars has...

We report the discovery of HATS-70b, a transiting brown dwarf at the deuterium burning limit. HATS-70b has a mass of M_p_=12.9_-1.6_^+1.8^ M_Jup_ and a radius of...

Photometric monitoring of beta Pictoris in 1981 showed anomalous fluctuations of up to 4% over several days, consistent with foreground material transiting the stellar disk. The...

A compilation of proper motions, radial velocities, and apparent magnitudes of B and A stars is combined with the absolute magnitudes and colour excesses from the "Catalogue of...

Photometric color excesses and distances plus heliocentric coordinates are calculated for 3762 southern A and early-F stars. The present results, combined with those previously...

Quantifying the composition of the material in protoplanetary disks is paramount to determining the potential for exoplanetary systems to produce and support habitable...

The presence of low-amplitude peaks over the noise in the power spectra of {delta} Sct stars is frequently disregarded. These seemingly insignificant peaks, collectively...

We present chemical composition and fundamental parameters (the effective temperature, surface gravity and radius) for four sharp-lined A-type stars gamma Gem (HD 41705),...

Accurately measuring stellar parameters is a key goal to increase our understanding of the observable Universe. However, current methods are limited by many factors, in...

From sector 1-44 TESS observations, 19 new rapidly oscillating Ap (roAp) stars, 103 ostensibly non-peculiar stars with roAp-like frequencies, and 617 {delta} Scuti stars with...

E+A galaxies are believed to be a short phase connecting major merger ultraluminous infrared galaxies (ULIRGs) with red and dead elliptical galaxies. Their optical spectrum...

A comprehensive model atom was developed for Si I-II-III using the most up-to-date atomic data available so far. Based on non-local thermodynamic equilibrium (NLTE) line...

Frequency analysis of long-term ultraprecise photometry can lead to precise values of rotation frequencies of rotating stars with 'hump and spike' features in their...

We present the first asteroseismic results for {delta} Scuti and {gamma} Doradus stars observed in Sectors 1 and 2 of the TESS mission. We utilize the 2-min cadence TESS data...

It has long been thought that starspots are not present in the A and B stars because magnetic fields cannot be generated in stars with radiative envelopes. Space observations...

Recently, high-precision optical 2-min cadence light curves obtained with TESS for targets located in the mission's defined first four sectors have been released. The majority...

Rotation modulation of Kepler light curves in mid-A to late-B stars is shown to be present. This is demonstrated by the high correlation of projected rotational velocities with...

We present the results of a thorough search for amplitude modulation of pulsation modes in 983 {delta} Sct stars, which have effective temperatures between...