Context. The spectral analysis of hot, massive stars is a fundamental astrophysical method of determining their intrinsic properties and feedback. With their inherent, radiation-driven winds, the quantitative spectroscopy for hot, massive stars requires detailed numerical modeling of the atmosphere and an iterative treatment in order to obtain the

TTT (Two-meter Twin Telescope) installation is a network of four telescopes located at the Teide Observatory, in the island of Tenerife (Canary Islands, Spain). TTT1 and TTT2 telescopes are two 0.80 m AltAz telescopes with two Nasmyth ports of both telescopes (f/4.4 and f/6.8). The f/4.4 is equipped with QHY411M cameras, composed of 151 Mpixel 3.76

We report the spectroscopic confirmation and fundamental properties of TOI$-$757 b, a mini$-$Neptune on a 17.5$-$d orbit transiting a bright star ($V\, =\, 9.7$ mag) discovered by the TESS mission. We acquired high$-$precision radial velocity measurements with the HARPS, ESPRESSO, and PFS spectrographs to confirm the planet detection and determine

Context. The ESO public survey VISTA Variables in the Vía Láctea (VVV) surveyed the inner Galactic bulge and the adjacent southern Galactic disk from 2009–2015. Upon its conclusion, the complementary VVV extended (VVVX) survey has expanded both the temporal as well as spatial coverage of the original VVV area, widening it from 562 to 1700 sq. deg

Unraveling the nature of dark matter (DM) stands as a primary objective in modern physics. Here we present evidence suggesting deviations from the collisionless cold DM (CDM) paradigm. It arises from the radial distribution of stars in six ultrafaint dwarf (UFD) galaxies measured with the Hubble Space Telescope. After a trivial renormalization in

Measuring the environments of massive galaxies at high redshift is crucial to understanding galaxy evolution and the conditions that gave rise to the distribution of matter we see in the Universe today. While high-z radio galaxies (HzRGs) and quasars tend to reside in protocluster-like systems, the environments of their radio-quiet counterparts are