The proper characterization of the least massive population of the young Sigma Orionis star cluster is required to understand the form of the cluster mass function and its impact on our comprehension of the substellar formation processes. S Ori 70 (T5.5+/-1) and 73, two T-type cluster member candidates, are likely to have masses between 3 and 7 MJup if their age is 3 Myr. It awaits confirmation whether S Ori 73 has a methane atmosphere. We aim to: i) confirm the presence of methane absorption in S Ori 73 by performing methane imaging; ii) study S Ori 70 and 73 cluster membership via

The Kepler spacecraft is monitoring the brightness of more than 150,000 stars  in the constellations Cygnus, Lyra,  and Draco. The photometric time series with micromagnitude precision are excellent for the study of stellar oscillations. The oscillations lead to small changes in brightness and are caused by waves trapped inside the stars. The field of asteroseismology uses information from the stellar oscillations to infer information from the stellar internal structure. The delta Scuti and gamma Doradus stars are two classes of oscillating stars of spectral type A and F that are slightly

The Butterfly Nebula (Minkowski 2-9) is an outstanding example of a highly collimated outflow from an evolved star. The formation of these extreme nebular geometries -i.e. how the (quasi)spherical symmetry that characterizes all the evolution of a solar-like star is broken when its envelope is ejected-  is one of the most debated and controversial topics in the study of the late stages of stellar evolution. Minkowski 2-9 gives us clear hints of what it might going on. This hourglass-shaped nebula is extraordinary in several aspects, but its  outstanding characteristic is undoubtedly its

One remaining open question regarding the physical properties of  Lyaemitters (LAEs) is their dust content and its evolution  with redshift. The variety of results is large and with those reported  by now is difficult to establish clear relations between dust, other  fundamental parameters of galaxies (star-formation rate, metallicity  or age) and redshift. In this Letter, we report Herschel  PACS-100mm, PACS-160mm and Spitzer MIPS-24mm  detections of a sample of spectroscopically GALEX-selected LAEs at  z~0.3 and~1.0. Five out of ten and one out of two LAEs are detected in, at least, one

We report far-infrared (FIR) imaging of the Seyfert 2 galaxy NGC 3081 in the range 70- 500 μm, obtained with an unprecedented angular resolution, using the Herschel Space Observatory instruments PACS and SPIRE. The 11 kpc (∼70′′) diameter star-forming ring of the galaxy appears resolved up to 250 μm. We extracted infrared (1.6-500 μm) nuclear fluxes, that is active nucleus-dominated fluxes, and fitted them with clumpy torus models, which successfully reproduce the FIR emission with small torus sizes. Adding the FIR data to the near- and mid-infrared spectral energy distribution (SED) results

The abundance ratios between key elements such as iron and α-process elements carry a wealth of information on the star formation history (SFH) of galaxies. So far, simple chemical evolution models have linked [α/Fe ] with the SFH time-scale, correlating large abundance ratios with short-lived SFH. The incorporation of full spectral fitting to the analysis of stellar populations allows for a more quantitative constraint between [α/Fe ] and the SFH. In this letter, we provide, for the first time, an empirical correlation between [α/Fe ] (measured from spectral indices) and the SFH (determined