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.

  • Upper panel: Example of a spectrum contained in the Fabry-Pérot data where we detect three pairs of emission peaks symmetrically spaced with the emission of the H ii region, which correspond to the presence of three expanding shells.Lower panel: Expansion
    Using a specialized technique sensitive to the presence of expanding ionized gas, we have detected a set of three concentric expanding shells in an H ii region in the nearby spiral galaxy M33. The detection was done using Fabry-Pérot spectroscopy, which allows us to map the ionized gas emission line Hα with exceptional precision in the spatial and spectral coordinates. We also took long-slit spectra of colisionally excited emission lines, which showed that the shells are likely originated from supernova explosions. Using the flux and the kinematics we estimated the kinetic energy in the
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  • Correlation of 5-sigma between the number of Tidal Dwarf Galaxies around a parent spiral galaxy and the bulge index.
    Dark matter is a type of material which has not been observed through any telescope, but whose existence is deduced from its gravitational effects on visible matter. In 1974 the astronomer Vera Rubin measured the rotation curves of the stars in orbit around the centres of spiral galaxies and noticed that at distances greater than a certain radial distance from the nucleus the stars rotate at virtually constant velocity, independently of their distance from the  centre of rotation. However the estimates of the mass of the visible matter, the stars and the gas in the galaxy lead to predictions
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  • Composition of the earthshine, the light reflected from the Earth to the night-time face of the Moon, and the figure showing the monthly mean apparent albedo anomalies from December 1998 through December 2014. Anomalies were calculated over the mean of th
    The Earth’s albedo is a fundamental climate parameter for understanding the radiation budget of the atmosphere. It has been traditionally measured from space platforms, but also from the ground for sixteen years from Big Bear Solar Observatory by observing the Moon. The photometric ratio of the dark (earthshine) to the bright (moonshine) sides of the Moon is used to determine nightly anomalies in the terrestrial albedo, with the aim is of quantifying sustained monthly, annual and/or decadal changes. We find two modest decadal scale cycles in the albedo, but with no significant net change
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  • Median stack images of P/2016 G1 obtained with the OSIRIS instrument of the 10.4m GTC through a Sloan r′ filter, at the indicated dates. North is up, East to the left. The directions opposite to Sun and the negative of the orbital velocity motion are show
    We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4m Gran Telescopio Canarias ( GTC)  from 2016 late April to early June.  Activated asteroids are objects in orbits typical of asteroids with unlike origin in the cometary reservoirs (the Oort Cloud or the trans-neptunian belt), that ejected dust by any mechanism: sublimation of volatiles (like comets do); collision with another asteroid or rotational disruption. The images of P/2016 G1 show a dust cometary-like coma and were analysed by comparing them with simulated images obtained using a computed
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  • Top panel: orbital phase shift at the time of the inferior conjunction (orbital phase 0), Tn, of the secondary star in the black hole X-ray binary Nova Muscae 1991 versus the orbital cycle number, n, folded on the best-fitting parabolic fit. The error bar
    We present new medium-resolution spectroscopic observations of the black hole X-ray binary Nova Muscae 1991 taken with X-Shooter spectrograph installed at the 8.2-m VLT telescope. These observations allow us to measure the time of inferior conjunction of the secondary star with the black hole in this system that, together with previous measurements, yield an orbital period decay of (dP/dt)= −20.7±12.7 ms yr −1 (−24.5 ± 15.1 μs per orbital cycle). This is significantly faster than those previously measured in the other black hole X-ray binaries A0620-00 and XTE J1118+480. No standard black
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  • Ks/F814W flux ratio (or extinction map) with emission line contours of the [OIII] gas in green. The brighter regions denote higher extinction and hence dust absorption. The conical morphology of the ionized gas is clearly defined by a horned-shaped dust s
    In some AGN, nuclear dust lanes connected to kpc-scale dust structures provide all the extinction required to obscure the nucleus, challenging the role of the dusty torus proposed by the Unified Model. In this letter we show the pc-scale dust and ionized gas maps of Circinus constructed using sub-arcsec-accuracy registration of infrared VLT AO images with optical Hubble Space Telescope images. We find that the collimation of the ionized gas does not require a torus but is caused by the distribution of dust lanes of the host galaxy on ~10 pc scales. This finding questions the presumed torus
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