H II regions are ionized nebulae associated with the formation of massive stars. They exhibit a wealth of emission lines in their spectra that form the basis for estimation of chemical composition. The amount of heavy chemical elements is essential to the understanding of important phenomena such as nucleosynthesis, star formation and chemical evolution of galaxies. For over 80 years, however, a discrepancy exists of a factor of around two between heavy-element abundances (the so-called metallicity) derived from the two main kinds of emission lines that can be measured in nebular spectra
The 19th scientific meeting of CARMENES, a collaboration of more than 100 scientists from 11 Spanish and German institutions aimed at studying extrasolar planets around M-type dwarf stars, the lowest mass stars, was held this week at the IACTEC facilities in La Laguna (Tenerife, Spain). Since it became operational in 2016, CARMENES has analysed more than 360 such stars, leading to the discovery of more than 65 new planets, making it the most efficient instrument and mapper in the study of planets around very low-mass stars, with 30 % of the total number of planets discovered in this range
A study led by researcher Laura Scholz, of the Instituto de Astrofísica de Canarias (IAC) has found, for the first time, observational evidence that the evolution and the properties of the galaxies are conditioned not only by the mass of the stars they contain, but aso by the effect of the dark matter halos which surround them. The results are published in the specialist journal Nature Astronomy. Dark matter comprises around 85% of all the matter in the Universe. Although ordinary matter absorbs, reflects and emits light, dark matter cannot be seen directly, which makes its detection
