| 1. |
- Scandariato, G., et al.
(författare)
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CHEOPS (CHaracterizing ExOPlanets Satellite) Mission
- 2016
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Ingår i: Proceedings of Science. - 1824-8039. ; 2016-May
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Tidskriftsartikel (refereegranskat)abstract
- The Characterizing ExOPlanet Satellite (CHEOPS) mission was selected in October 2012 by ESA as the first small mission. It will be a ultra-high precision photometer dedicated to the observation of transits of known exoplanets on bright stars, for which the mass has already been measured via ground-based spectroscopic surveys. Its precision will allow the accurate determination of the planetary radii and, by consequence, the planetary bulk density. CHEOPS will also unveil transiting exoplanets of interest for in-depth characterization, a legacy for future instruments suited to the spectroscopic characterization of exoplanetary atmospheres.
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| 2. |
- Borsato, Riccardo, et al.
(författare)
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On non-abelian T-duality and deformations of supercoset string sigma-models
- 2017
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer-Verlag New York. - 1126-6708 .- 1029-8479. ; :10
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Tidskriftsartikel (refereegranskat)abstract
- We elaborate on the class of deformed T-dual (DTD) models obtained by first adding a topological term to the action of a supercoset sigma model and then performing (non-abelian) T-duality on a subalgebra g˜ of the superisometry algebra. These models inherit the classical integrability of the parent one, and they include as special cases the so-called homogeneous Yang-Baxter sigma models as well as their non-abelian T-duals. Many properties of DTD models have simple algebraic interpretations. For example we show that their (non-abelian) T-duals — including certain deformations — are again in the same class, where g˜ gets enlarged or shrinks by adding or removing generators corresponding to the dualised isometries. Moreover, we show that Weyl invariance of these models is equivalent to g˜ being unimodular; when this property is not satisfied one can always remove one generator to obtain a unimodular g˜ , which is equivalent to (formal) T-duality. We also work out the target space superfields and, as a by-product, we prove the conjectured transformation law for Ramond-Ramond (RR) fields under bosonic non-abelian T-duality of supercosets, generalising it to cases involving also fermionic T-dualities.
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| 3. |
- Nespral, D., et al.
(författare)
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Mass determination of K2-19b and K2-19c from radial velocities and transit timing variations
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601, s. Article Number: A128-
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Tidskriftsartikel (refereegranskat)abstract
- We present radial velocity follow-up observations of K2-19, a compact planetary system hosting three planets, of which the two larger ones, K2-19b and K2-19c, are close to the 3: 2 mean motion resonance. An analysis considering only the radial velocity measurements detects K2-19b, the larger and more massive planet in the system, with a mass of 54.8 +/- 7.5 M-circle plus and provides a marginal detection of K2-19c, with a mass of M-c = 5.9(-4.3)(+7.6) M-circle plus. We also used the TRADES code to simultaneously model both our RV measurements and the existing transit timing measurements. We derived a mass of 54.4 +/- 8.9 M-circle plus for K2-19b and of 7.5(-1.4)(+3.0) M-circle plus for K2-19c. For K2-19b, these masses are consistent with a previous determination that was principally based on a photodynamical analysis of the K2-19 light curve. Differences remain mainly in the mass determination of the more lightweight planet, driven likely by the limited precision of the RV measurements and possibly some as yet unrecognized systematics.
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