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Raul Melia

Publications and source records attributed to Raul Melia.

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Secular Light Curve of Exocomet 3I/ATLAS, and its Location on a Comet Evolutionary Diagram

In this work we will create the Secular Light Curve (SLC) of exocomet 3I/ATLAS, using the SLC-Methodology (Ferrin 2010-2023). The SLCs give a throve of new information and allow the comparison of exo-comets with comets of our own solar system. We arrive at the following conclusions: The colors of 3I are consistent and lie inside the area of colors of other comets in our solar system. The SLC of this comet exhibits a photometric anomaly, a region from -120 to -45 days before perihelion that we interpreted as an eclipse, suggesting that 3I might also be a binary. At -45 days, the SLC changes abruptly its slope, reaching a maximum absolute magnitude of mV(1,1,{\alpha}) = 6.8+-0.1. Using reported estimates derived from 97 papers in the arXiv.org depository for the size, dust, H2O, CO2, and CO production rates, we calculate the total mass loss. We use the inverse total mass loss, as a proxy for age. The Mass-Loss Age = 0.16 comet years will be plotted in the horizontal axis of a Comet Evolutionary Diagram (CED) while the number of Remaining Returns defined as RR = r/{\Delta}r = 24, will be plotted in the vertical axis of the CED. 3I/ATLAS exocomet lies among the comets of our Oort comet family. We conclude that 3I is a comet of the Oort Cloud, but from a different stellar system. The Evolutionary Diagram presented in this work shows complexity beyond current understanding

astro-ph.EP

TOROS Optical follow-up of the Advanced LIGO-VIRGO O2 second observational campaign

We present the results of the optical follow-up, conducted by the TOROS collaboration, of gravitational wave events detected during the Advanced LIGO-Virgo second observing run (Nov 2016 -- Aug 2017). Given the limited field of view ($\sim100\arcmin$) of our observational instrumentation we targeted galaxies within the area of high localization probability that were observable from our sites. We analyzed the observations using difference imaging, followed by a Random Forest algorithm to discriminate between real and bogus transients. For all three events that we respond to, except GW170817, we did not find any bona fide optical transient that was plausibly linked with the observed gravitational wave event. Our observations were conducted using telescopes at Estación Astrof\'ısica de Bosque Alegre, Cerro Tololo Inter-American Observatory, and the Dr. Cristina V. Torres Memorial Astronomical Observatory. Our results are consistent with the LIGO-Virgo detections of a binary black hole merger (GW170104) for which no electromagnetic counterparts were expected, as well as a binary neutron star merger (GW170817) for which an optical transient was found as expected.

astro-ph.HE