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.

  • This figure displays the results from the Bayesian comparison for coronal loop models as: M0: uniform flux tubes; M1: density stratified flux tubes; M2: expanding magnetic flux tubes. (a) Marginal likelihood as a function of the observed period ratio, r,
    We present the first application of Bayesian model comparison techniques for solar atmospheric seismology. The detection of multiple mode harmonic kink oscillations in coronal loops enables to obtain information on coronal density stratification and magnetic field expansion using seismology inversion techniques. The inference is based on the measurement of the period ratio between the fundamental mode and the first overtone and theoretical results for the period ratio under the hypotheses of coronal density stratification and magnetic field expansion of the wave guide. We present a Bayesian
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  • Upper panel: composite image of NGC 6946 obtained by adding all the wavelengths for the Hα scan. The circle indicates the position of region at RA: 308.6998566 degrees, DEC: +60.1772541 degrees. Lower panel: spectral energy distribution for Hα + [NII] (le
    Using the OSIRIS tunable narrow band imager on the 10.4m GTC (La Palma) we have mapped the SAB(rs)cd galaxy NGC 6946 over a 7.3x7.5 square arcminutes field in the emission lines of the [SII]\lambda\lambda, 6717, 6731 doublet, and in H\alpha. From these maps we have produced catalogs of the H\alpha luminosities and effective radii of 557 HII regions across the disk, and derived the [SII] emission line ratios of 370 of these. The H\alpha observations were used to derive the mean luminosity-weighted electron densities for the regions of the sample, while the [SII] line ratios allowed us to
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  • (a) Visible spectra of DA14 obtained with CAFOS at the 2.2m CAHA telescope (black) and OSIRIS at GTC (red). Filled circles are the reflectance R values obtained from the fotometry. (b) Same as the top panel, but adding the R values for the near-infrared.
    Near-Earth asteroid 2012 DA 14 made its closest approach on February 15, 2013, when it passed at a distance of 27,700 km from the Earth’s surface. It was the first time an asteroid of moderate size was predicted to approach that close to the Earth, becoming bright enough to permit a detailed study from ground-based telescopes. Asteroid 2012 DA 14 was poorly characterized before its closest approach. The main objective of this work was to obtain new and valuable data to better understand its physical properties, and to evaluate the effects of such a close approach on the object. We acquired
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  • Fig. 1: Top panel: orbital phase shift at the time of the inferior conjunction (orbital phase 0), Tn, of the secondary star in the BHXB XTE J1118+480 versus the orbital cycle number, n, folded on the best-fit parabolic fit. The error bars give the observa
    We present new 10.4 m-GTC/OSIRIS spectroscopic observations of the black hole X-ray binary XTE J1118+480 that confirm the orbital period decay at (dP/dt) = −1.90 ± 0.57 ms yr −1. This corresponds to a period change of −0.88 ± 0.27 μs per orbital cycle. We have also collected observations of the black hole X-ray binary A0620–00 to derive an orbital period derivative of (dP/dt)= −0.60 ± 0.08 ms yr −1 (−0.53 ± 0.07 μs/cycle). Angular momentum losses due to gravitational radiation are unable to explain these large orbital decays in these two short- period black hole binaries. The orbital period
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