We have modelled the stellar and nebular continua and emission-line intensity ratios of massive stellar populations in the Antennae galaxy using high resolution and self-consistent libraries of model H II regions around central clusters of ageing stars. The model libraries are constructed using the stellar population synthesis code, STARBURST99

The Transiting Exoplanet Survey Satellite mission was designed to find transiting planets around bright, nearby stars. Here, we present the detection and mass measurement of a small, short-period (≍4 days) transiting planet around the bright (V = 7.9), solar-type star HD 86226 (TOI-652, TIC 22221375), previously known to host a long-period (∼1600

The high-resolution, dual channel, visible and near-infrared spectrograph CARMENES offers exciting opportunities for stellar and exoplanetary research on M dwarfs. In this work we address the challenge of reaching the highest radial velocity precision possible with a complex, actively cooled, cryogenic instrument, such as the near-infrared channel

The He I infrared (IR) triplet at 10 830 Å is known as an activity indicator in solar-type stars and has become a primary diagnostic in exoplanetary transmission spectroscopy. He I IR lines are a tracer of the stellar extreme-ultraviolet irradiation from the transition region and corona. We study the variability of the He I triplet lines in a

Obtaining and characterizing the extended point-spread function (PSF) is essential to extract accurate photometric information from deep imaging surveys. In this contribution, we present the extended PSFs of the Sloan Digital Sky Survey (SDSS). By stacking images of individual stars with different brightness, two-dimensional SDSS PSFs extending

The Radial Velocity Experiment (RAVE) is a magnitude-limited (9 < I < 12) spectroscopic survey of Galactic stars randomly selected in Earth's southern hemisphere. The RAVE medium-resolution spectra (R ∼ 7500) cover the Ca-triplet region (8410-8795 Å). The sixth and final data release (DR6) is based on 518,387 observations of 451,783 unique stars