Browsing by Author "Colazo, C."

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    Observations of the First Electromagnetic Counterpart to a Gravitational-wave Source by the TOROS Collaboration
    (2017) Díaz, Marco A.; Macri, L.; Lambas, D.; Oliveira, C.; Castellón, J.; Ribeiro, T.; Sánchez, B.; Schoenell, W.; Abramo, L.; Padilla, Nelson; Akras, S.; Alcaniz, J.; Artola, R.; Beroiz, M.; Bonoli, S.; Cabral, J.; Camuccio, R.; Castillo, M.; Chavushyan, V.; Coelho, P.; Colazo, C.
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    Physical properties of Centaur (60558) 174P/Echeclus from stellar occultations
    (2024) Pereira, C. L.; Braga-Ribas, F.; Sicardy, B.; Gomes-Junior, A. R.; Ortiz, J. L.; Branco, H. C.; Camargo, J. I. B.; Morgado, B. E.; Vieira-Martins, R.; Assafin, M.; Benedetti-Rossi, G.; Desmars, J.; Emilio, M.; Morales, R.; Rommel, F. L.; Hayamizu, T.; Gondou, T.; Jehin, E.; Artola, R. A.; Asai, A.; Colazo, C.; Ducrot, E.; Duffard, R.; Fabrega, J.; Fernandez-Valenzuela, E.; Gillon, M.; Horaguchi, T.; Ida, M.; Kitazaki, K.; Mammana, L. A.; Maury, A.; Melita, M.; Morales, N.; Moya-Sierralta, C.; Owada, M.; Pollock, J.; Sanchez, J. L.; Santos-Sanz, P.; Sasanuma, N.; Sebastian, D.; Triaud, A.; Uchiyama, S.; Vanzi, L.; Watanabe, H.; Yamamura, H.
    The Centaur (60558) Echeclus was discovered on 2000 March 03, orbiting between the orbits of Jupiter and Uranus. After exhibiting frequent outbursts, it also received a comet designation, 174P. If the ejected material can be a source of debris to form additional structures, studying the surroundings of an active body like Echeclus can provide clues about the formation scenarios of rings, jets, or dusty shells around small bodies. Stellar occultation is a handy technique for this kind of investigation, as it can, from Earth-based observations, detect small structures with low opacity around these objects. Stellar occultation by Echeclus was predicted and observed in 2019, 2020, and 2021. We obtain upper detection limits of rings with widths larger than 0.5km and optical depth of tau = 0.02. These values are smaller than those of Chariklo's main ring; in other words, a Chariklo-like ring would have been detected. The occultation observed in 2020 provided two positive chords used to derive the triaxial dimensions of Echeclus based on a 3D model and pole orientation available in the literature. We obtained a = 37.0 +/- 0.6km, b = 28.4 +/- 0.5km, and c = 24.9 +/- 0.4km, resulting in an area-equivalent radius of 30.0 +/- 0.5km. Using the projected limb at the occultation epoch and the available absolute magnitude (), we calculate an albedo of p(v) = 0.050 +/- 0.003. Constraints on the object's density and internal friction are also proposed.
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    TOROS optical follow-up of the advanced LIGO–VIRGO O2 second observational campaign
    (2020) Artola, R.; Beroiz, M.; Cabral, J.; Camuccio, R.; Castillo, M.; Chavushyan, V.; Colazo, C.; Cuevas, H.; DePoy, D. L.; Díaz, M. C.; Domínguez, M.; Dultzin, D.; Fernández, D.; Ferreyra, A. C.; Fonrouge, A.; Franco, J.; Graña, D.; Girardini, C.; Gurovich, S.; Kanaan, A.; Lambas, D. G.; Lares, M.; Hinojosa, A. F.; Hinojosa, A.; Hinojosa, A. F.; López-Cruz, O.; Macri, L. M.; Marshall, J. L.; Melia, R.; Mendoza, W.; Castelló, J. L. N.; Padilla, N.; Perez, V.; Peñuela, T.; Rattray, W.; Renzi, V.; Ríos-López, E.; Rivera, A. R.; Ribeiro, T.; Rodriguez, H.; Sánchez, B.; Schneiter, M.; Schoenell, W.; Starck, M.; Vrech, R.; Quiñones, C.; Tapia, L.; Tornatore, M.; Torres-Flores, S.; Vilchis, E.; Zadrożn, A.
    We present the methods and results of the optical follow-up, conducted by the Transient Optical Robotic Observatory of the South Collaboration, of gravitational wave events detected during the Advanced LIGO–Virgo second observing run (2016 November–2017 August). Given the limited field of view (∼100 arcmin) of our observational instrumentation, we targeted galaxies within the area of high localization probability that were observable from our sites. We analysed the observations using difference imaging, followed by a random forest algorithm to discriminate between real and spurious transients. Our observations were conducted using telescopes at Estación Astrofísica de Bosque Alegre, Cerro Tololo Inter-American Observatory, the Dr. Cristina V. Torres Memorial Astronomical Observatory, and an observing station in Salta, Argentina.