Mass and eccentricity constraints on the planetary debris orbiting the white dwarf WD 1145+017

Being the first of its kind, the white dwarf WD 1145+017 exhibits a complex system of disintegrating debris which offers a unique opportunity to study its disruption process in real time. Even with plenty of transit observations there are no clear constraints on the masses or eccentricities of such debris. Using N-body simulations, we show that masses greater than ≃1020 kg (a tenth of the mass of Ceres) or orbits that are not nearly circular (eccentricity > 10−3) dramatically increase the chances of the system becoming unstable within 2 yr, which would contrast with the observational data over this timespan. We also provide a direct comparison between transit phase shifts detected in the observations and by our numerical simulations

Disseny i realització d’una campanya de mesures aerodinàmiques sobre objectes

El túnel de vent és una eina d’investigació emprada en aerodinàmica per estudiar l’efecte del moviment de l’aire al voltant d’objectes sòlids. En aquest projecte, s’ha dut a terme una campanya de mesures aerodinàmiques en el túnel de vent de l’Escola Superior d’Enginyeria de Telecomunicació i Aeronàutica de Castelldefels (EETAC) amb anemometria de fil calent i amb Tub de Pitot sobre el perfil cilíndric AF101, el perfil alar NACA 0012 i diversos automòbils a escala. D’aquesta manera, s’han trobat els principals paràmetres aerodinàmics que els caracteritzen. Finalment, s’han extret conclusions de la resistència aerodinàmica que presenten els automòbils tot comparant les seves forces de drag.2014/201

Transiting Disintegrating Planetary Debris around WD 1145+017

More than a decade after astronomers realized that disrupted planetary material likely pollutes the surfaces of many white dwarf stars, the discovery of transiting debris orbiting the white dwarf WD 1145+017 has opened the door to new explorations of this process. We describe the observational evidence for transiting planetary material and the current theoretical understanding (and in some cases lack thereof) of the phenomenon.Comment: Invited review chapter. Accepted March 23, 2017 and published October 7, 2017 in the Handbook of Exoplanets. 15 pages, 10 figure

Restriccions en massa i excentricitat per WD 1145+017

Most stars in the Universe will eventually end their lives as white dwarfs: Earth-sized burned-out stellar cores, prevented from further collapsing by the pressure of degenerate electrons. Interest in the study of white dwarfs ranges from testing our knowledge of stellar structure and evolution to the progenitors of the extremely luminous type Ia supernovae that led to the discovery of dark energy. However, over the past decade, white dwarfs also opened up a new area of research on exo-planets. Since the discovery of the first extra-solar planet in 1995, we now know that haBeing the first of its kind, the white dwarf WD 1145+017 exhibits a complex system of disintegrating debris which offers a unique opportunity to study its disruption process in real time. Even with plenty of transit observations there are no clear constraints on the masses or eccentricities of such debris. Using N-body simulations we show that masses greater than a tenth of the mass of Ceres or orbits that are not nearly circular dramatically increase the chances of the system becoming unstable within two years, which would contrast with the observational data over this timespan. We also provide a direct comparison between transit phase shifts detected in the observations and by our numerical simulations.Siendo la primera de su tipo, la enana blanca WD 1145+017 muestra un complejo sistema de planetas orbitándola. Este trabajo usa simulaciones numéricas para determinar restricciones en masa y excentricidad para los cuerpos orbitando WD 1145+017.Sent la primera de la seva classe, la nana blanca WD 1145+017 llueix un complex sistema de planetes orbitant-la. Aquest treball utilitza simulacions numèriques per determinar restriccions en massa i excentricitat pels objectes orbitant WD 1145+017

Restriccions en massa i excentricitat per WD 1145+017

Most stars in the Universe will eventually end their lives as white dwarfs: Earth-sized burned-out stellar cores, prevented from further collapsing by the pressure of degenerate electrons. Interest in the study of white dwarfs ranges from testing our knowledge of stellar structure and evolution to the progenitors of the extremely luminous type Ia supernovae that led to the discovery of dark energy. However, over the past decade, white dwarfs also opened up a new area of research on exo-planets. Since the discovery of the first extra-solar planet in 1995, we now know that haBeing the first of its kind, the white dwarf WD 1145+017 exhibits a complex system of disintegrating debris which offers a unique opportunity to study its disruption process in real time. Even with plenty of transit observations there are no clear constraints on the masses or eccentricities of such debris. Using N-body simulations we show that masses greater than a tenth of the mass of Ceres or orbits that are not nearly circular dramatically increase the chances of the system becoming unstable within two years, which would contrast with the observational data over this timespan. We also provide a direct comparison between transit phase shifts detected in the observations and by our numerical simulations.Siendo la primera de su tipo, la enana blanca WD 1145+017 muestra un complejo sistema de planetas orbitándola. Este trabajo usa simulaciones numéricas para determinar restricciones en masa y excentricidad para los cuerpos orbitando WD 1145+017.Sent la primera de la seva classe, la nana blanca WD 1145+017 llueix un complex sistema de planetes orbitant-la. Aquest treball utilitza simulacions numèriques per determinar restriccions en massa i excentricitat pels objectes orbitant WD 1145+017

The art of discovery

This photograph originally appeared in the 2018 Research student photography and image competition held to celebrate National Science Week (11-19 August 2018). Blurb: A small, simple, hand-made telescope absorbing the multicoloured light of the Milky Way contrasts with the immensity and complexity of the Universe. Siting at quiet desks, new and creative ideas are investigated by astronomers everyday to fully unravel the mysteries that surround us

Disseny i realització d’una campanya de mesures aerodinàmiques sobre objectes

El túnel de vent és una eina d’investigació emprada en aerodinàmica per estudiar l’efecte del moviment de l’aire al voltant d’objectes sòlids. En aquest projecte, s’ha dut a terme una campanya de mesures aerodinàmiques en el túnel de vent de l’Escola Superior d’Enginyeria de Telecomunicació i Aeronàutica de Castelldefels (EETAC) amb anemometria de fil calent i amb Tub de Pitot sobre el perfil cilíndric AF101, el perfil alar NACA 0012 i diversos automòbils a escala. D’aquesta manera, s’han trobat els principals paràmetres aerodinàmics que els caracteritzen. Finalment, s’han extret conclusions de la resistència aerodinàmica que presenten els automòbils tot comparant les seves forces de drag.2014/201

Pendulum dynamics in an amusement park

Pendulums have long been used to to determine the kinematics of non-inertial rotating systems. A proper study of this classical mechanical device under the action of a rotating reference frame can fully describe the behavior of such non-inertial systems. In such venue, we have placed a pendulum inside a rotating plane ride in an amusement park, and determined the parameters defining the rotation of the ride by solely analyzing the pendulum's motion. We present two different methodologies to determine the motion patterns of the ride as well as a computer-based reproduction of the trajectory of the pendulum throughout the ride.Postprint (published version