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.

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  • Average magnetic field of the quiet Sun as inferred from the observational data. Black contours display the frontier between granules and intergranules (i.e., Ic = 1.0, where Ic is the continuum intensity). The magnetic field strength color bar has been clipped at 800 G.
    Research news
    Mapping the hidden magnetic field of the quiet Sun
    The Sun is the only star where we can resolve the intricate magnetism that all convective stars harbor. Yet, more than 99% of its visible surface along the solar cycle (the so-called quiet Sun) is filled with a tangled, unresolved magnetism. These “hidden” fields are thought to store enough magnetic energy to play a role in the heating of the Sun’s outer atmosphere, but its field strength is still not constrained. Previous investigations based on the Hanle effect in atomic lines claim a strong magnetization of about 100 G, while the same effect in molecules show a factor of 10 weaker fields
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  • Lithium in Brown Dwarf
    Press release
    Astronomers discover ancient brown dwarf with lithium deposits intact
    A team of researchers at the Instituto de Astrofísica de Canarias (IAC) and the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Mexico, has discovered lithium in the oldest and coldest brown dwarf where the presence of this valuable element has been confirmed so far. This substellar object, called Reid 1B, preserves intact the earliest known lithium deposit in our cosmic neighbourhood, dating back to a time before the formation of the binary system to which it belongs. The discovery was made using the OSIRIS spectrograph on the Gran Telescopio Canarias (GTC), at the Roque de
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  • NUV-optical-NIR colour-colour diagrams of our sample of Milky Way stars, as a density plot. As reference, a stellar track covering a range of surface temperatures (6500-18000 K) is shown in several cases of dust extinction.
    Research news
    Constraints on the dust extinction law of the Galaxy
    This work explores data from a few surveys, most notably the serendipitous catalogue from the NASA SWIFT mission that made use of the NUV/optical camera UVOT (originally designed to pinpoint the location of Gamma Ray Bursts). We select a sample of 10452 stars, cross matched with Gaia DR2 and 2MASS data, covering a large spectral window, from NUV to NIR. We compare these data with generic dust extinction models that parameterise the wavelength dependence into the steepness of the law, the net extinction in the V band (Av), and the strength of the prominent NUV bump. We recover well known
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  • GTC light curve of PG1144+005 (top) and its Fourier amplitude spectrum showing the detected pulsation periods (bottom).
    Research news
    Discovery of pulsations in the nitrogen-rich PG1159 star PG 1144+005
    Up to 98% of all single stars will eventually become white dwarfs - stars that link the history and future evolution of the Galaxy, and whose previous evolution is engraved in their interiors. Those interiors can be studied using asteroseismology, utilizing stellar pulsations as seismic waves. The pulsational instability strips of DA and DB white dwarf stars are pure, allowing for the important generalization that their interior structure represents that of all DA and DB white dwarfs. This is not the case for the hottest pulsating white dwarfs, the GW Vir stars: only about 50% of white
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  • Top: final transmission spectrum and retrieved models for HAT-P-65b. The white circles refer to the data. The blue line and shading show the results from the full retrieval, while the red line and shading from the K-muted retrieval. Bottom: retrieved temperature-pressure (T-P) profiles and mass fractions for the full retrieval (left two) and K-muted retrieval (right two), respectively.
    Research news
    Detection of TiO and Na in the atmosphere of the hot Jupiter HAT-P-65b
    We present the low-resolution transmission spectra of the puffy hot Jupiter HAT-P-65b (0.53 MJup, 1.89 RJup, Teq = 1930 K), based on two transits observed using the OSIRIS spectrograph on the 10.4 m Gran Telescopio CANARIAS. The transmission spectra of the two nights are consistent, covering the wavelength range 517–938 nm and consisting of mostly 5 nm spectral bins. We perform equilibrium-chemistry spectral retrieval analyses on the jointly fitted transmission spectrum and obtain an equilibrium temperature of 1645 (-244+255) K and a cloud coverage of 36 (-17+23) %, revealing a relatively
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  • Optical spectrum from the VHE gamma-ray blazar S4 0954+65. The detection of the emission lines allows us to firmly establish the redshift and the characteristics of the source.
    Research news
    Characterization of the host galaxy from gamma-ray blazars
    The most extreme electromagnetic radiation that can be observed is known as very high energy gamma rays (VHE, E>100 GeV). It is the last window open to the Universe, thanks to the development of the Cherenkov telescopes. The extragalactic VHE sky is still nowadays vastly unexplored, only composed of around 80 known sources. The great majority of them are classified as blazars, a type of Active Galactic Nuclei (AGN) whose relativistic jets point in the direction of the Earth boosting their emission. While the observation of the gamma-ray emission is crucial to understand the extreme physical
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