News

This section includes scientific and technological news from the IAC and its Observatories, as well as press releases on scientific and technological results, astronomical events, educational projects, outreach activities and institutional events.

  • Figure Caption: Teff and log gc estimates for the Galactic (red circles) and LMC (gray triangles) O-type dwarfs as a function of SpT; corresponding linear fits are overplotted with red and black dashed lines.  The figures show the scatter found in effecti
    We are now in an era of large spectroscopic surveys of OB-type stars. Quantitative spectroscopic analysis of these modern datasets is enabling us to review the physical properties of blue massive stars with robust samples, not only revisiting mean properties and general trends, but also incorporating information about the effects of second-order parameters. We investigate the spectral type -- effective temperature (SpT - Teff) calibration for O-type dwarfs, and its claimed dependence on metallicity, using statistically-meaningful samples of stars extracted from the IACOB and VFTS surveys. We
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  • Figure caption: Scenario for the magnetospheric origin of the gamma-rays: A maximally rotating black hole with event horizon rg (black sphere) accretes plasma from the center of the galaxy IC 310. In the apple-shaped ergosphere (blue) extending to 2rg in
    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20%
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  • Figure caption: Data of LMC extreme stars are shown as solid, grey circles in the Spitzer color-magnitude diagram ([3.6]-[8.0] vs. [8.0]). The position of the models during the AGB evolution are also shown (where different colors correspond to different s
    For the first time we use self-consistent evolutionary models of low-and intermediate-mass stars (1-8 solar masses) coupled with theoretical dust formation models to follow the evolution of these stars during the Asymptotic Giant Branch (AGB) in the Spitzer Space Telescope two-color and color-magnitude diagrams. These models are the first able to identify the main regions in the Spitzer diagrams occupied by AGB stars in the Large Magellanic Cloud (LMC). The main diagonal sequences traced by LMC extreme stars in the two-color and color-magnitude Spitzer diagrams are nicely fit by carbon stars
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  • Figure caption: Simulation of the ultraluminous X-Ray source ULX P13. Crédits: Image created by Tom Russell (ICRAR) using the software created by Rob Hynes (Louisiana State University).
    Three decades ago one of the first astronomical satellites designed toobserve X-rays detected a new type of object: it had a much higher luminosity than any star, but much lower than other types of identified sources, such as the nuclei of active galaxies. They were dubbed, in a not very imaginative way, ultraluminous X rays (ULX) sources. Even recently we were still not really sure what they are. In this work, we have managed to solve this mystery and we have found that the mechanism which produces such a large luminosity in the most thoroughly studied ULX is not, as many had hoped, an
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  • Figure caption: Simulation of the magnetic field distribution (represented by lines whose lengths are proportional to the field strength) in a “cool” white dwarf. The darker zone is a cooler region where the intense magnetic field has partially blocked th
    Isolated cool white dwarf stars more often have strong magnetic fields than young, hotter white dwarfs which has been a puzzle because magnetic fields are expected to decay with time but a cool surface suggests that the star is old. In addition, some white dwarfs with strong fields vary in brightness as they rotate, which has been variously attributed to surface brightness inhomogeneities similar to sunspots, chemical inhomogeneities  and other magnetooptical effects. Here we describe optical observations of the brightness and magnetic field of the cool white dwarf WD1953-011 taken over
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