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.

  • K-band nuclear spectra of LLAGN extracted from our SINFONI data in r = 0.3” apertures. The prominent emission lines are from H2 (marked at the top of the figure), the strongest being 1-0 S(1) at 2.12 μm. Several stellar absorption features (like the 12CO
    We present observations of the molecular gas in the nuclear environment of three prototypical low luminosity AGN (LLAGN), based on VLT/SINFONI AO-assisted integral-field spectroscopy of H 2 1-0 S(1) emission at angular resolutions of ~0.17”. On scales of 50-150 pc the spatial distribution and kinematics of the molecular gas are consistent with a rotating thin disk, where the ratio of rotation ( V) to dispersion (σ) exceeds unity. However, in the central 50 pc, the observations reveal a geometrically and optically thick structure of molecular gas ( V / σ < 1 and N H > 10 23 cm -2) that is
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  • In this work, the planetary system of the planet-host star 55Cnc has been studied. In this system, there is an Earth-like planet that shows a chemical composition very different from that of the Earth.
    Simulations have shown that a diverse range of extrasolar terrestrial planet bulk compositions are likely to exist based on the observed variations in host star elemental abundances. Based on recent studies, it is expected that a significant proportion of host stars may have Mg/Si ratios below 1. Here we examine this previously neglected group of systems. Planets simulated as forming within these systems are found to be Mg-depleted (compared to Earth), consisting of silicate species such as pyroxene and various feldspars. Planetary carbon abundances also vary in accordance with the host star
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  • The spectrum of the LFC, taken with HARPS, together with the spectrum of a star. Image credit: ESO
    The best spectrographs are limited in stability by their calibration light source. Laser frequency combs are the ideal calibrators for astronomical spectrographs. They emit a spectrum of lines that are equally spaced in frequency and that are as accurate and stable as the atomic clock relative to which the comb is stabilized. Absolute calibration provides the radial velocity of an astronomical object relative to the observer (on Earth). For the detection of Earth-mass exoplanets in Earth-like orbits around solar-type stars, or of cosmic acceleration, the observable is a tiny velocity change
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  • Artist’s impression of the hypergiant star HR 8752 traversing the Yellow Evolutionary Void (YEV). The image shows the increase in temperature undergone by the surface of the star in recent decades.. /© A.Lobel-ROB. SRON.
    Context. We study the time history of the yellow hypergiant HR 8752 based on high-resolution spectra (1973-2005), the observed MK spectral classification data, B - V- and V-observations (1918-1996) and yet earlier V-observations (1840-1918). Aims: Our local thermal equilibrium analysis of the spectra yields accurate values of the effective temperature (T eff), the acceleration of gravity (g), and the turbulent velocity (v t) for 26 spectra. The standard deviations average are 82 K for T eff, 0.23 for log g, and 1.1 km s -1 for v t. Methods: A comparison of B - V observations, MK spectral
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