Ultra-diffuse galaxies (UDGs) were recently recognized as an abundant class of low-surface brightness galaxies with unusually large sizes -- found both in galaxy clusters and in the field. The nature and origins of these galaxies are unclear, with one intriguing possibility that some of them are "failed Milky Ways" with massive halos but a paucity

We study the damping of longitudinal oscillations of a prominence thread caused by the mass accretion. We suggested a simple model describing this phenomenon. In this model we considered a thin curved magnetic tube filled with the plasma. The prominence thread is in the central part of the tube and it consists of dense cold plasma. The parts of the

We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight, with polarized emission data at sub-millimetric (sub-mm) bands for the Vela C molecular cloud. The sub-mm data were obtained by the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) during the 2012

Context. Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. Aims: We present a detailed spectroscopic analysis of 74 solar-type stars, 42 of which are known to harbour planets. We determine the nitrogen abundances of

The globular cluster 47 Tuc exhibits a complex sub-giant branch (SGB) with a faint-SGB comprising only about the 10 per cent of the cluster mass and a bright-SGB hosting at least two distinct populations. We present a spectroscopic analysis of 62 SGB stars including 21 faint-SGB stars. We thus provide the first chemical analysis of the intriguing

The detection of structures in the sky with optical surface brightnesses fainter than 30 mag arcsec‑2 (3σ in 10 × 10 arcsec boxes; r-band) has remained elusive in current photometric deep surveys. Here we show how present-day telescopes of 10 m class can provide broadband imaging 1.5–2 mag deeper than most previous results within a reasonable