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.

  • Figure caption: Left : (FUV − NUV) versus (NUV − [3.6]) color-color diagram. Morphological types are represented by color (see legend). We define the blue and red sequence by dividing the plot into two regions and fitting a least-squares 1-D polynomial (a
    We obtained GALEX FUV, NUV, and Spitzer/IRAC 3.6 µm photometry for >2000 galaxies, available for 90% of the S4G sample. We find a very tight "GALEX Blue Sequence (GBS)" in the (FUV − NUV) versus (NUV − [3.6]) color-color diagram which is populated by irregular and spiral galaxies, and is mainly driven by changes in the formation timescale (τ ) and a degeneracy between τ and dust reddening. The tightness of the GBS provides an unprecedented way of identifying starforming galaxies and objects that are just evolving to (or from) what we call the "GALEX Green Valley (GGV)". At the red end of the
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  • The hypothesis of a universal initial mass function (IMF) - motivated by observations in nearby stellar systems - has been recently challenged by the discovery of a systematic variation of the IMF with the centralvelocity dispersion, σ, of early-type galaxies (ETGs), towards an excessof low-mass stars in high-σ galaxies. This trend has been derived so farfrom integrated spectra, and remains unexplained at present. To testwhether such trend depends on the local properties within a galaxy, we have obtained new, extremely deep, spectroscopic data, for three nearby ETGs, two galaxies with high σ
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  • Schematic picture of a tornado-like magnetic structure. Solid lines are the three-dimensional representation of the magnetic field lines. Dashed lines are thepoloidal field lines in the azimuthal plane.
    Recent high-resolution and high-cadence observations have surprisingly suggested that prominence barbs exhibit apparent rotating motions suggestive of a tornado-like structure. Additional evidence has been provided by Doppler measurements. The observations reveal opposite velocities for both hot and cool plasma on the two sides of a prominence barb. This motion is persistent for several hours and has been interpreted in terms of rotational motion of prominence feet. Several authors suggest that such barb motions are rotating helical structures around a vertical axis similar to tornadoes on
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  • Colour-magnitude diagram (a form of the Hertzsprung-Russell diagram) of the globular cluster M13. The AGB stars of the first and second generations are shown in blue and red, respectively, while the less evolved red giants are shown in green. Crédits: ada
    Galactic globular clusters (GCs) are known to host multiple stellar populations: a first generation (FG) with a chemical pattern typical of halo field stars and a second generation (SG) enriched in Na and Al and depleted in O and Mg. Both stellar generations are found at different evolutionary stages (e.g., the main-sequence turnoff, the subgiant branch, and the red giant branch (RGB)). The non-detection of SG asymptotic giant branch (AGB) stars in several metal-poor ([Fe/H] < ‑1) GCs suggests that not all SG stars ascend the AGB phase, and that failed AGB stars may be very common in metal
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  • Figure caption: NEA discovery stack images. The field of view (FOV) is 2 arcmin x 2 arcmin in normal sky orientation. 2014 OL339 could be barely seen in the upper side, while for EUHT400 we include only the last four of the available six images.
    Since 2006, the European Near Earth Asteroids Research (EURONEAR)project has been contributing to the research of near-Earth asteroids (NEAs) within a European network. One of the main aims is the amelioration of the orbits of NEAs, and starting in 2014 February we focus on the recovery of one-opposition NEAs using the Isaac Newton Telescope (INT) in La Palma in override mode. As a part of this NEA recovery project, since 2014 June EURONEAR serendipitously started to discover and secure the first NEAs from La Palma using the INT, and thanks to the teamwork including amateurs and students who
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