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.

  • GJ 1214b transit light curves obtained with GTC/OSIRIS tunable filters. In the bottom panels, the residuals of the curve fit are shown for each filter.
    Aims. The super-Earth planet GJ 1214b has recently been the focus of several studies, which use the transit spectroscopy technique to determine the nature of its atmosphere. Here, we focus on the Halpha line as a tool to further restrict the nature of GJ 1214b’s atmosphere. Methods. We used the Gran Telescopio Canarias (GTC) OSIRIS instrument to acquire narrow-band photometry with tunable filters. We were able to observe the primary transit of the super-Earth GJ 1214 in three bandpasses: two centered in the continuum around Halpha (653.5 nm and 662.0 nm) and one centered at the line core
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  • Stellar radial velocity curve for DY Cen. The deviations of observations to the computed fit for the best orbital parameters are shown in the bottom. The notation of the observations is shown in the inset.
    The stellar origin of the extremely hydrogen-deficient R Coronae Borealis (RCB) stars has remained a mystery for astronomers since their discovery more than two hundred years ago.  Two competing scenarios are commonly advocated. In the first one, a final helium shell flash occurs on a cooling white dwarf star or a very late thermal pulse is experienced by a post-AGB star. The second scenario involves the merger of two white dwarfs: a carbon–oxygen white dwarf accretes ahelium white dwarf. Evidence from the chemical compositions of RCB stars suggests that most are products of a merger
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  • Bar fraction distribution as function of the galaxy magnitudes (left panels) and masses (right panels). The bar fraction calculated using all the Hubble types (fT) and only the disk galaxies (fD) are plotted in the upper and bottom panels, respectively. T
    The effects that interactions produce on galaxy disks and how they modify the subsequent formation of bars need to be distinguished to fully understand the relationship between bars and environment. To this aim we derive the bar fraction in three different environments ranging from the field to Virgo and Coma Clusters, covering an unprecedentedly large range of galaxy luminosities (or, equivalently, stellar masses). We confirm that the fraction of barred galaxies strongly depends on galaxy luminosity. We also show that the difference between the bar fraction distributions as a function of
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  • Fields observed with HST for M32 (F1) and M31 (F2) overplotted on a M32 image from ground.
    We use deep Hubble Space Telescope Advanced Camera for Surveys/High Resolution Channel observations of a field within M32 (F1) and an M31 background field (F2) to determine the star formation history (SFH) of M32 from its resolved stellar population. We find that 2-5 Gyr old stars contribute ~40% ± 17% of M32's mass, while ~55% ± 21% of M32's mass comes from stars older than 5 Gyr. The SFH additionally indicates the presence of young (<2 Gyr old), metal-poor ([M/H] ~ –0.7) stars, suggesting that blue straggler stars contribute ~2% of the mass at F1; the remaining ~3% of the mass is in young
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  • The remnant of the SN1006. The surveyed area is indicated by the large green circle. The centre of the survey (the centroid of the X-ray emission) is marked with a green cross, and that of the Ha emission, by the small yellow circle. This is a composite i
    Type-Ia supernovae are thought to occur when a white dwarf made of carbon and oxygen accretes sufficient mass to trigger a thermonuclear explosion. The accretion could be slow, from an unevolved (main-sequence) or evolved (subgiant or giant) star (the single-degenerate channel), or rapid, as the primary star breaks up a smaller orbiting white dwarf (the double-degenerate channel). A companion star will survive the explosion only in the single-degenerate channel. Both channels might contribute to the production of type-Ia supernovae, but the relative proportions of their contributions remain
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  • Spectra of DY Cen (in red) around 400 nm (or 4000 Å). The spectra of the nearby star HD 115842 (in blue) and the Extreme Helium star BD -9 4395 (in green) are also displayed for comparison. Note the presence of a new absorption band at 400 nm (the new 400
    Fullerenes and fullerene-related molecules have been proposed as explanations for unidentified astronomical features such as the intense UV absorption band at 217 nm and the enigmatic diffuse interstellar bands (DIBs), In order to shed light on the a long-standing DIB’s problem, we search high-resolution and high-quality VLT/UVES optical spectra of the hot R Coronae Borealis (RCB) star DY Cen for electronic transitions of the neutral C 60 fullerene molecule and DIBs. We report the non-detection of the strongest C 60 electronic transitions (e.g., those at ∼376, 398, and 402 nm). DIBs towards
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