A study published in the Astrophysical Journal supports models which question the need for the existence of this form of matter in galaxies

It will be its closest approach to the Earth (its perigee), at a distance of around 107 million kilometres, which is very close, considering that it originated in the Oort Cloud, at a distance from us of about a light year (some 9.5 billion kilometres). Although on those nights it will attain maximum brightness, it has not been as bright as was expected, so that it is not easy to find it with the naked eye. So binoculars are necessary, and a sky map, and we need to be at a place with dark sky to see the central zone of the comet. In spite of that it can be found near the Great Bear, and this

El presidente del Gobierno de Canarias visita el IAC Hoy, viernes 8 de enero, el presidente del Gobierno de Canarias, Fernando Clavijo, ha visitado la sede del Instituto de Astrofísica de Canarias (IAC), en La Laguna, para reunirse personalmente con el Director del centro, Rafael Rebolo, y conocer de primera mano los proyectos en los que está involucrado el Instituto. En dicho encuentro, se le han planteado distintos asuntos que conciernen al estado actual del IAC, como el progreso de su plan estratégico y el de las grandes instalaciones telescópicas para los Observatorios de Canarias

Ultra diffuse galaxies (UDGs) have the sizes of giants but the luminosities of dwarfs. A key to understanding their origins comes from their total masses, but their low surface brightnesses (mu > 25.0) generally prohibit dynamical studies. Here we report the first such measurements for a UDG (VCC 1287 in the Virgo cluster), based on its globular cluster system dynamics and size. From 7 GCs we measure a mean systemic velocity Vsys = 1071(-15+14) km/s, thereby confirming a Virgo-cluster association. We measure a velocity dispersion of 33(-10+16) km/s within 8.1 kpc, corresponding to an

For more than 70 years we have known that the weak recombination lines of the ions of elements, such as oxygen and carbon, give us values for their abundances that are much larger than those obtained using collisional lines, even though the collisional lines are 1,000 to 100,000 times brighter than the recombination lines. This discrepancy has cast constant doubt about one of the methods that has been mostly used to measure chemical abundances in the Universe. During the past few years the planetary nebulae group at the IAC have discovered that the planetary nebulae with the largest

The polarization of the Mg II k line at 279.5 nm encodes valuable information on the magnetic field of the upper solar chromosphere, where this strong resonance line originates. We have developed a novel radiative transfer code which allows us to account for scattering polarization and the Hanle and Zeeman effects, as well as partial frequency redistribution (PRD) phenomena (i.e., correlation effects between the incoming and outgoing photons in the scattering events). This non-LTE code, which treats the atomic system and the polarized radiation field quantum-mechanically, has been applied to