Sérgio R. A. Gomes
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Sérgio R. A. Gomes has a total of 19 co-authors. Here are the top co-authors by number of shared publications:
Alexandre C.M. Correia
2 shared publicationsAlexandre C. M. Correia
CFisUC, Departamento de Física, Universidade de Coimbra, 3004-516 Coimbra, Portugal
1 shared publication- Alexandre C. M. Correia
CFisUC, Departamento de Física, Universidade de Coimbra
1 shared publication - Ana Lourenço
Centre for Earth and Space Research of the University of Coimbra, Department of Earth Sciences, University of Coimbra, Coimbra, Portugal
1 shared publication - Antonija Oklopčić
Anton Pannekoek Institute for Astronomy, University of Amsterdam
1 shared publication - Hinna Shivkumar
University of Amsterdam
1 shared publication
Latest Publications
- Open Access
- 11 July 2026
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 551 (1)
CHEOPS observations of V1298 Tau: updated planetary densities and implications on the early evolution of the young system
The young (10–30 Myr) multiplanet system V1298 Tau presents a unique opportunity to probe the early formation and evolution of young systems. We present new CHEOPS observations of the three innermost planets, yielding high-precision planetary radii ($\sim$5–11 R$_{\oplus }$) and improving the radius ratios ($R_{\mathrm{p}}/R_{\mathrm{s}}$) by 30-71 per cent compared to previous multiple TESS observations. Combined with refined period and mass determinations from transit-timing variation measurements, we derive revised bulk densities (0.06–0.23 $\rm g\,cm^{-3}$) for these planets. We find that the innermost planet c is denser compared to the outermost planet at the 3.4$\sigma$ level, while the bulk densities of the three outermost planets are consistent within the reported uncertainties. These bulk densities suggest differing envelope mass fraction across the system, indicating differential atmospheric evolution in the young system. We further assess the early dynamical state of the V1298 Tau system and find that within the range of simulations performed we find no evidence for present-day mean-motion resonance trapping. As an independent diagnostic, we compute the forced eccentricities and low normalized angular momentum deficit exhibited by the system. Our simulations suggest that no past dynamical excitation is required to explain the present orbital architecture.- 11 July 2026
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 551 (1)
Open AccessCHEOPS observations of V1298 Tau: updated planetary densities and implications on the early evolution of the young system
The young (10–30 Myr) multiplanet system V1298 Tau presents a unique opportunity to probe the early formation and evolution of young systems. We present new CHEOPS observations of the three innermost planets, yielding high-precision planetary radii ($\sim$5–11 R$_{\oplus }$) and improving the radius ratios ($R_{\mathrm{p}}/R_{\mathrm{s}}$) by 30-71 per cent compared to previous multiple TESS observations. Combined with refined period and mass determinations from transit-timing variation measurements, we derive revised bulk densities (0.06–0.23 $\rm g\,cm^{-3}$) for these planets. We find that the innermost planet c is denser compared to the outermost planet at the 3.4$\sigma$ level, while the bulk densities of the three outermost planets are consistent within the reported uncertainties. These bulk densities suggest differing envelope mass fraction across the system, indicating differential atmospheric evolution in the young system. We further assess the early dynamical state of the V1298 Tau system and find that within the range of simulations performed we find no evidence for present-day mean-motion resonance trapping. As an independent diagnostic, we compute the forced eccentricities and low normalized angular momentum deficit exhibited by the system. Our simulations suggest that no past dynamical excitation is required to explain the present orbital architecture. - Open Access
- 13 June 2023
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 674, A111
Effect of the inclination in the passage through the 5/3 mean motion resonance between Ariel and Umbriel
The orbits of the main satellites of Uranus are expected to slowly drift away owing to tides raised in the planet. As a result, the 5/3 mean motion resonance between Ariel and Umbriel was likely encountered in the past. Previous studies have shown that, in order to prevent entrapment in this resonance, the eccentricities of the satellites must be larger than ~0.01 at the epoch, which is hard to explain. On the other hand, if the satellites experience some temporary capture and then escape, the inclinations rise to high values that are not observed today. We have revisited this problem both analytically and numerically focussing on the inclination, using a secular two-satellite model with circular orbits. We show that if the inclination of Umbriel was around 0.15° at the time of the 5/3 resonance encounter, capture can be avoided in about 60% of the cases. Moreover, after the resonance crossing, the inclination of Umbriel drops to a mean value around 0.08°, which is close to the presently observed one. The final inclination of Ariel is distributed between 0.01° and 0.25° with a nearly equal probability, which includes the present mean value of 0.02°.
- 13 June 2023
- Published by EDP Sciences in Astronomy & Astrophysics
- Vol. 674, A111
Open AccessEffect of the inclination in the passage through the 5/3 mean motion resonance between Ariel and Umbriel
The orbits of the main satellites of Uranus are expected to slowly drift away owing to tides raised in the planet. As a result, the 5/3 mean motion resonance between Ariel and Umbriel was likely encountered in the past. Previous studies have shown that, in order to prevent entrapment in this resonance, the eccentricities of the satellites must be larger than ~0.01 at the epoch, which is hard to explain. On the other hand, if the satellites experience some temporary capture and then escape, the inclinations rise to high values that are not observed today. We have revisited this problem both analytically and numerically focussing on the inclination, using a secular two-satellite model with circular orbits. We show that if the inclination of Umbriel was around 0.15° at the time of the 5/3 resonance encounter, capture can be avoided in about 60% of the cases. Moreover, after the resonance crossing, the inclination of Umbriel drops to a mean value around 0.08°, which is close to the presently observed one. The final inclination of Ariel is distributed between 0.01° and 0.25° with a nearly equal probability, which includes the present mean value of 0.02°.
- Open Access
- 1 December 2022
- Published by Cambridge University Press (CUP) in Proceedings of the International Astronomical Union
- Vol. 18 (S382) , 103-109
Stability maps for the 5/3 mean motion resonance between Ariel and Umbriel with inclination
The evolution of the five largest satellites of Uranus during the crossing of the 5/3 mean motion resonance between Ariel and Umbriel is strongly affected by chaotic motion. Studies with numerical integrations of the equations of motion and analysis of Poincaré surface sections provided helpful insights to the role of chaos on the system. However, they lack of a quantification of this chaos in the phase-space. Here, we construct stability maps using the frequency analysis method. We determine that for low energies (small eccentricity and/or inclinations), the phase-space is mainly stable. As the energy increases, the chaotic regions replace the stable motion, until only small, localized libration regions remain stable.
- 1 December 2022
- Published by Cambridge University Press (CUP) in Proceedings of the International Astronomical Union
- Vol. 18 (S382) , 103-109
Open AccessStability maps for the 5/3 mean motion resonance between Ariel and Umbriel with inclination
The evolution of the five largest satellites of Uranus during the crossing of the 5/3 mean motion resonance between Ariel and Umbriel is strongly affected by chaotic motion. Studies with numerical integrations of the equations of motion and analysis of Poincaré surface sections provided helpful insights to the role of chaos on the system. However, they lack of a quantification of this chaos in the phase-space. Here, we construct stability maps using the frequency analysis method. We determine that for low energies (small eccentricity and/or inclinations), the phase-space is mainly stable. As the energy increases, the chaotic regions replace the stable motion, until only small, localized libration regions remain stable.
- 1 July 2020
- Published by Elsevier in Astronomy and Computing
- Vol. 32
Comparison of automatic methods to detect sunspots in the Coimbra Observatory spectroheliograms
- 1 July 2020
- Published by Elsevier in Astronomy and Computing
- Vol. 32
Comparison of automatic methods to detect sunspots in the Coimbra Observatory spectroheliograms