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.

  • Fig. 1: Top panel: orbital phase shift at the time of the inferior conjunction (orbital phase 0), Tn , of the secondary star in the low-mass black hole X-ray binary XTE J1118+480 versus the orbital cycle number, n, folded on the best-fit parabolic fit. Gr
    We report the detection of an orbital period decay of (dP/dt)= -1.83+-0.66 ms yr–1  in the black hole X-ray binary XTE J1118+480. This corresponds to a period change of –0.85 ± 0.30 μs per orbital cycle, which is ~150 times larger than expected from the emission of gravitational waves. These observations cannot be reproduced by conventional models of magnetic braking even when including significant mass loss from the system. The spiral-in of the star is either driven by magnetic braking under extremely high magnetic fields in the secondary star or by a currently unknown process, which will
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  • False colour image (blue=J, green=H, red=KS) for the massive stellar cluster Masgomas-1. Massive stars with spectral classification are marked with red circles.//LIRIS/ Telescopio William Herschel.
    Recent near-infrared data have contributed to the discovery of new (obscured) massive stellar clusters and massive stellar populations in previously known clusters in our Galaxy. These discoveries lead us to view the Milky Way as an active star-forming machine. Aims: The main purpose of this work is to  determine physically the main parameters (distance, size, total mass and age) of Masgomas-1, the first massive cluster discovered by our systematic search programme. Methods: Using near-infrared ( J, H, and K S) photometry we selected 23 OB-type and five red supergiant candidates for multi
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  • Image of Fleming 1 obtained with the VLT.
    Stars are generally spherical, yet their gaseous envelopes oftenappear non-spherical when ejected near the end of their lives. Thisquirk is most notable during the planetary nebula phase when theseenvelopes become ionized. The most popular explanation is that theasymmetry, and in particular the formation of highly collimatedstructures such as the precessing jets observed in a number ofnebulae, is caused by interactions in a binary system. The study ofthe prototypical planetary nebula Fleming 1 with the VLT telescopedemonstrates for the first time that the hypothesis iscorrect. Indeed, it is
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  • Doppler shifts resulting from a two-components Gaussian fit of the He I 10830 triplet intensity profiles. The velocity is saturated at ± 6 km/s. Vertical lines delimit the prominence feet.
    We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the \ion{He}{1}~1083.0~nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent {\it hedgerow} prominence. The data show opposite Doppler shifts, $\pm$~6\kms, at the edges of the prominence feet. We argue
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  • Average star formation rates, (SFR), derived from averaged far-infrared luminosities of 1<z<3 AGNs, as a function of suLX.
    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlation between the mass of the black hole and the mass of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming
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  • Logarithm of the optical depth of the discontonuity between the magnetic and the non magnetic atmosphere (i.e. the base of the canopy). Large positive numbers mean deep in the atmosphere while large negative numbers are higher layers of the atmosphere. Th
    We analyze the spectral asymmetry of Stokes V (circularly polarized) profiles of an individual network patch in the quiet Sun observed by Sunrise/IMaX. At a spatial resolution of 0".15-0".18, the network elements contain substructure which is revealed by the spatial distribution of Stokes V asymmetries. The area asymmetry between the red and blue lobes of Stokes V increases from nearly zero at the core of the structure to values close to unity at its edges (single-lobed profiles). Such a distribution of the area asymmetry is consistent with magnetic fields expanding with height, i.e., an
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