References of "Castro-Tirado, A. J"
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See detailA Pluto-like radius and a high albedo for the dwarf planet Eris from an occultation
Sicardy, B.; Ortiz, J. L.; Assafin, M. et al

in Nature (2011), 478

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 ... [more ▼]

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163+/-6kilometres, density 2.52+/-0.05 grams per cm[SUP]3[/SUP] and a high visible geometric albedo, . No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ~1nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun. [less ▲]

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See detailMulti-wavelength observations of afterglow of GRB 080319B and the modeling constraints
Pandey, S. B.; Castro-Tirado, A. J.; Jelínek, M. et al

in Astronomy and Astrophysics (2009), 504(1), 45-51

We present observations of the afterglow of GRB 080319B at optical, mm and radio frequencies from a few hours to 67 days after the burst. Present observations along with other published multi-wavelength ... [more ▼]

We present observations of the afterglow of GRB 080319B at optical, mm and radio frequencies from a few hours to 67 days after the burst. Present observations along with other published multi-wavelength data have been used to study the light-curves and spectral energy distributions of the burst afterglow. The nature of this brightest cosmic explosion has been explored based on the observed properties and it's comparison with the afterglow models. Our results show that the observed features of the afterglow fits equally good with the Inter Stellar Matter and the Stellar Wind density profiles of the circum-burst medium. In case of both density profiles, location of the maximum synchrotron frequency $\nu_m$ is below optical and the value of cooling break frequency $\nu_c$ is below $X-$rays, $\sim 10^{4}$s after the burst. Also, the derived value of the Lorentz factor at the time of naked eye brightness is $\sim 300$ with the corresponding blast wave size of $\sim 10^{18}$ cm. The numerical fit to the multi-wavelength afterglow data constraints the values of physical parameters and the emission mechanism of the burst. [less ▲]

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See detailFlares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars
Castro-Tirado, A. J.; de Ugarte Postigo, A.; Gorosabel, J. et al

in Nature (2008), 455

Magnetars are young neutron stars with very strong magnetic fields of the order of 10[SUP]14[/SUP]-10[SUP]15[/SUP]G. They are detected in our Galaxy either as soft γ-ray repeaters or anomalous X-ray ... [more ▼]

Magnetars are young neutron stars with very strong magnetic fields of the order of 10[SUP]14[/SUP]-10[SUP]15[/SUP]G. They are detected in our Galaxy either as soft γ-ray repeaters or anomalous X-ray pulsars. Soft γ-ray repeaters are a rare type of γ-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical counterpart to the γ-ray flares or the quiescent source has yet been identified. Here we report multi-wavelength observations of a puzzling source, SWIFT J195509+261406. We detected more than 40 flaring episodes in the optical band over a time span of three days, and a faint infrared flare 11days later, after which the source returned to quiescence. Our radio observations confirm a Galactic nature and establish a lower distance limit of ~3.7kpc. We suggest that SWIFT J195509+261406 could be an isolated magnetar whose bursting activity has been detected at optical wavelengths, and for which the long-term X-ray emission is short-lived. In this case, a new manifestation of magnetar activity has been recorded and we can consider SWIFT J195509+261406 to be a link between the `persistent' soft γ-ray repeaters/anomalous X-ray pulsars and dim isolated neutron stars. [less ▲]

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See detailGRB 080319B: optical observations.
Jelinek, M.; Castro-Tirado, A. J.; Chantry, Virginie ULg et al

E-print/Working paper (2008)

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See detailGRB 080319B: second epoch imaging from canarias (correction to GCN7469).
Jelinek, M.; Castro-Tirado, A. J.; Chantry, Virginie ULg et al

E-print/Working paper (2008)

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See detailGRB 080315: optical observations.
de Ugarte Postigo, A.; Chantry, Virginie ULg; Castro-Tirado, A. J. et al

E-print/Working paper (2008)

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