A5029594418- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Spacecraft Design and Technology
- Satellite Communication Systems
- Spacecraft and Cryogenic Technologies
- History and Developments in Astronomy
- Astrophysical Phenomena and Observations
Instituto de Astronomía Teórica y Experimental
2013-2025
Consejo Nacional de Investigaciones Científicas y Técnicas
2013-2024
Trinity College Dublin
2019-2020
Universidad Nacional de Córdoba
2013-2020
Argentine National Observatory
2020
University of St Andrews
2017-2019
We present the discovery and characterisation of two transiting planets observed by \textit{TESS} in light curves young bright (V=9.67) star HD73583 (TOI-560). perform an intensive spectroscopic photometric space- ground-based follow-up order to confirm characterise system. found that is a ($\sim 500$~Myr) active with rotational period $12.08 \pm 0.11 $\,d, mass radius $ 0.73 0.02 M_\odot$ $0.65 R_\odot$, respectively. b ($P_b=6.3980420 _{ - 0.0000062 }^{+0.0000067}$ d) has $10.2...
We perform an analysis of ~80000 photometric measurements for the following 10 stars hosting transiting planets: WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our includes mainly transit lightcurves from Exoplanet Transit Database, public photometry literature, and some proprietary privately supplied by other authors. Half these were obtained amateurs. From this we derive 306 timing measurements, as well improved planetary parameters. Additionally, 6 present a set...
High-energy stellar irradiation can photoevaporate planetary atmospheres, which be observed in spectroscopic transits of hydrogen lines. For the exoplanet HD189733b, multiple observations Ly-$\alpha$ line have shown that atmospheric evaporation is variable, going from undetected to enhanced a $1.5$-year interval. Coincidentally or not, when HD189733b was evaporating, flare had just occurred 8h prior observation. This led question whether this temporal variation due flare, an unseen...
Close-in hot Jupiters are exposed to a tremendous photon flux that ionizes the neutral escaping material from planet leaving an observable imprint makes them interesting laboratory for testing theoretical models. In this work, we present 3D hydrodynamic simulations with radiation transfer calculations of close-in exoplanet in blow-off state. We calculate Ly α absorption and compare it observations HD 209458b previous simplified model results. Our results show interaction together proper...
Lyman $\alpha$ observations during an exoplanet transit have proved to be very useful study the interaction between stellar wind and planetary atmosphere. They been extensively used constrain system parameters that are not directly observed, such as mass loss rate. In this way, Ly can a powerful tool infer existence of magnetic field, since it is expected latter will affect escaping material. To explore effect fields on absorption HD 209458b, we run set 3D MHD simulations including dipolar...
Atmospheric escape is a fundamental process that affects the structure, composition, and evolution of many planets. The signatures are detectable on close-in, gaseous exoplanets orbiting bright stars, owing to high levels extreme-ultraviolet irradiation from their parent stars. Colorado Ultraviolet Transit Experiment (CUTE) CubeSat mission designed take advantage near-ultraviolet stellar brightness distribution conduct survey extended atmospheres nearby close-in CUTE payload magnifying NUV...
We present a 3D hydrodynamic study of the effects that different stellar wind conditions and planetary structures have on calculated Ly-$\alpha$ absorptions produced during transit HD 209458b. Considering range speeds $\sim$[350-800] km s$^{-1}$, coronal temperature $\sim$[3-7] $\times10^{6}$ K two values polytropic index $\Gamma$ $\sim$[1.01-1.13], while keeping fixed mass loss rate, we found $\dot M_p$ between $\sim$[3-5] $\times 10^{10}$g s$^{-1}$ give account for observational absorption...
We use 3D hydrodynamics simulations followed by synthetic line profile calculations to examine the effect increasing strength of stellar wind has on observed Ly-$\alpha$ transits a Hot Jupiter (HJ) and Warm Neptune (WN). find that mass-loss rate from 0 (no wind) 100 times solar value causes reduced atmospheric escape in both planets (a reduction 65\% 40\% for HJ WN, respectively, compared "no wind" case). For weaker winds (lower ram pressure), planetary is very small. However, as becomes...
We homogeneously analyse $\sim 3.2\times 10^5$ photometric measurements for 1100$ transit lightcurves belonging to $17$ exoplanet hosts. The data cover $16$ years 2004--2019 and include amateur professional observations. Old archival were reprocessed using up-to-date exoplanetary parameters empirically debiased limb-darkening models. also derive self-consistent radial-velocity fits $13$ targets. confirm the nonlinear TTV trend in WASP-12 at a high significance, with consistent magnitude....
Here, we study the dichotomy of escaping atmosphere newly discovered close-in exoplanet AU Mic b. On one hand, high EUV stellar flux is expected to cause a strong atmospheric escape in other wind this young star believed be very strong, which could reduce or even inhibit planet's escape. thought have mass-loss rate that up $1000$ times larger than solar ($\dot{M}_\odot$). To investigate dichotomy, perform 3D hydrodynamics simulations wind--planetary interactions system and predict synthetic...
The GJ 436 planetary system is an extraordinary system. Neptune-size planet that orbits the M3 dwarf revealed in Ly$\alpha$ line extended neutral hydrogen atmosphere. This material fills a comet-like tail obscures stellar disc for more than 10 hours after transit. Here, we carry out series of 3D radiation hydrodynamic simulations to model interaction wind with escaping With these models, seek reproduce $\sim56\%$ absorption found transits, simultaneously lack H$\alpha$ Varying strength and...
We report the discovery of a warm Neptune and hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), bright (V=9.9) G9 dwarf star in visual binary system observed by TESS space mission Sectors 5 6. performed ground-based follow-up observations -- comprised LCOGT transit photometry, NIRC2 adaptive optics imaging, FIES, CORALIE, HARPS, HIRES, PFS high-precision Doppler measurements confirmed planetary nature 16-day candidate announced team. discovered an additional radial velocity...
Abstract The observational signatures of prominences have been detected in single and binary G K type stars for many years now, but recently this has extended to the M dwarf regime. Prominences carry away both mass angular momentum when they are ejected impact on any orbiting planets may be important evolution exoplanetary atmospheres. By means classification used massive star community, that involves knowledge two parameters (the co-rotation Alfvén radii, rK rA), we determined which cool...
Lyman $\alpha$ observations of the transiting exoplanet HD 209458b enable study exoplanets exospheres exposed to stellar EUV fluxes, as well interacting wind properties. In this we present 3D hydrodynamical models for stellar-planetary interaction including radiation pressure and charge exchange, together with photoionization, recombination collisional ionization processes. Our explore contribution exchange on Ly$\alpha$ absorption profile in a framework, single set parameters appropriate...
Context. Young solar analogs reaching the main sequence experience very strong magnetic activity, generating angular momentum losses through wind and mass ejections. Aims. We investigate signatures of fields activity at surface in prominence system ultra-rapid rotator V530 Per, a G-type solar-like member young open cluster α Persei. This object has rotation period that is shorter than all stars with available maps. Methods. With time-series spectropolarimetric observations gathered ESPaDOnS...
ABSTRACT Stellar high-energy radiation (X-ray and extreme ultraviolet, XUV) drives atmospheric escape in close-in exoplanets. Given that stellar irradiation depends on the magnetism stars have magnetic cycles, we investigate how cycles affect evolution of exoplanetary escape. First, consider a hypothetical HD209458b-like planet orbiting Sun. For that, implement observed solar XUV available over one half 1D hydrodynamic model HD209458b. We find rates show cyclic variation (from 7.6 to 18.5 ×...
Abstract Coronal Mass Ejections (CMEs) erupting from the host star are expected to affect atmospheric erosion processes of planets. For planets with a magnetosphere, embedded magnetic field in CMEs is thought be most important parameter planetary mass loss. In this work, we investigate effect different structures stellar on atmosphere hot Jupiter dipolar magnetosphere. We use time-dependent 3D radiative magnetohydrodynamics (MHD) escape model that self-consistently models outflow Jupiter’s...
At young ages, when radiation from the host star is high, and planet hot inflated after formation, planetary atmospheric mass loss can be extremely strong compared to older planets. In turn, stellar winds are faster denser for stars evolved main-sequence stars. Their interaction with escaping atmospheres substantially affect rates, as well observable signatures of atmospheres, both effects expected occur differently We perform a comparative study two systems around similar masses but very...
ABSTRACT Atmospheric escape in exoplanets has traditionally been observed using hydrogen Lyman-α and Hα transmission spectroscopy, but more recent detections have utilized the metastable helium triplet at 1083 nm. Since this feature is accessible from ground, it offers new possibilities for studying atmospheric escape. Our goal to understand how observability of escaping evolves during lifetime a highly irradiated gas giant. We extend our previous work on 1D self-consistent hydrodynamic...
Although the present-day Sun rotates too slowly to exhibit centrifugally supported 'slingshot prominences', at some time during its past it may have formed these clouds of cool gas and ejected them into interplanetary medium. We determine period for this behaviour using a rotation evolution code derive properties formation ejection slingshot prominences lifetime star similar our Sun. The mass, mass-loss rate, rate are calculated analytical expression derived in previous work. find that stars...
The two planetary systems TOI-942 and TOI-421 share many similar characteristics, apart from their ages (50~Myr 9~Gyr). Each of the stars hosts sub-Neptune-like planets at orbits in mass ranges. In this paper, we aim to investigate whether similarity host configuration can be taken as proof that were formed evolved a way. paper I series, performed comparative study these using 3D modeling atmospheric escape its interaction with stellar wind, for four planets. We demonstrated though strong...
Coronal Mass Ejections (CMEs) erupting from the host star are expected to have effects on atmospheric erosion processes of orbiting planets. For planets with a magnetosphere, embedded magnetic field in CMEs is thought be most important parameter affect planetary mass loss. In this work, we investigate effect different structures stellar atmosphere hot Jupiter dipolar magnetosphere. We use time-dependent 3D radiative magnetohydrodynamics (MHD) escape model that self-consistently models...
Abstract We present a 3D magnetohydrodynamic study of the effect that stellar and planetary magnetic fields have on calculated Lyα absorption during transit, employing parameters resemble exoplanet HD209458b. assume dipolar field for both star planet, use Parker solution to initialize wind. also consider radiative processes radiation pressure. numerical MHD code Guacho run several models varying values moments within range reported in literature. found presence influences escaping neutral...