Untitled

Southworth, Jane; Pfeifer, Rebecca A.; Habeck, M.; Randolph, J. C.; Doering, Otto C.; Johnston, J. J.; Rao, Dasappaiah Ganesh

doi:10.1023/a:1015266425630

Cited by 58 publications

(28 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Manual time checks were performed for images in most observing sequences, and no discrepancies were noticed 1 . We have previously found a good agreement between the timestamps on the Danish and MPG 2.2m telescopes (Southworth et al 2015), supporting the reliability of both. Southworth et al (2009b) used an early version of DEFOT so the 2008 data were re-reduced with the current version.…”

Section: Data Reductionsupporting

confidence: 66%

Transit timing variations in the WASP-4 planetary system

Southworth

Dominik

Jørgensen

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Transits in the planetary system WASP-4 were recently found to occur 80 s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that confirm the existence of transit timing variations, and are well fitted by a quadratic ephemeris with period decay dP/dt = −9.2 ± 1.1 ms yr −1 . We rule out instrumental issues, stellar activity and the Applegate mechanism as possible causes. The light-time effect is also not favoured due to the non-detection of changes in the systemic velocity. Orbital decay and apsidal precession are plausible but unproven. WASP-4 b is only the third hot Jupiter known to show transit timing variations to high confidence. We discuss a variety of observations of this and other planetary systems that would be useful in improving our understanding of WASP-4 in particular and orbital decay in general. ⋆ Based on data collected by MiNDSTEp with the Danish 1.54 m telescope at the ESO La Silla Observatory. c 0000 RAS 2 Southworth et al.

show abstract

Section: Data Reductionsupporting

confidence: 66%

Transit timing variations in the WASP-4 planetary system

Southworth

Dominik

Jørgensen

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Following the general approach, which we also adopted in our previous studies (e.g. Mancini et al 2014;Southworth et al 2015;Tregloan-Reed et al 2018), we made a new fit of the light curves to estimate the ratio of the radii, k, but fixing the other photometric parameters to their best values (Tables 3 and 4). The uncertainties of k were estimated by performing 20 000 Monte Carlo simulations.…”

Section: Variation Of the Planetary Radius With Wavelengthmentioning

confidence: 99%

Physical properties and transmission spectrum of the WASP-74 planetary system from multiband photometry

Mancini

Southworth

Mollière

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present broad-band photometry of eleven planetary transits of the hot Jupiter WASP-74 b, using three medium-class telescopes and employing the telescopedefocussing technique. Most of the transits were monitored through I filters and one was simultaneously observed in five optical (U, g ′ , r ′ , i ′ , z ′ ) and three near infrared (J, H, K) passbands, for a total of 18 light curves. We also obtained new high-resolution spectra of the host star. We used these new data to review the orbital and physical properties of the WASP-74 planetary system. We were able to better constrain the main system characteristics, measuring smaller radius and mass for both the hot Jupiter and its host star than previously reported in the literature. Joining our optical data with those taken with the HST in the near infrared, we built up an observational transmission spectrum of the planet, which suggests the presence of strong optical absorbers, as TiO and VO gases, in its atmosphere.

show abstract

“…For some of these planets, theoretical calculations have been done using the Roche model by Budaj (2011) and correct the derived spherical radii and densities for the expected planet deformation (e.g. Southworth et al 2015;Delrez et al 2016). Correia (2014) formulated an analytical model for computing the shape of a deformed planet based on the fluid second Love number and also showed the difference between light curves of deformed and spherical planets.…”

Section: Lsstc Data Science Fellowmentioning

confidence: 99%

Detectability of shape deformation in short-period exoplanets

Akinsanmi

Barros

Santos

et al. 2019

A&A

View full text Add to dashboard Cite

Context. Short-period planets suffer from extreme tidal forces from their parent stars. These forces deform the planets causing them to attain non-spherical shapes. The non-spherical shapes, modeled here as triaxial ellipsoids, can have an impact on the observed transit light-curves and the parameters derived for these planets. Aims. We investigate the detectability of tidal deformation in short-period planets from their transit light curves and the instrumental precision needed. We also aim to show how detecting planet deformation allows us to obtain an observational estimate of the second fluid Love number from the light curve which gives valuable information about the planet's internal structure. Methods. We adopted a model to calculate the shape of a planet due to the external potentials acting on it and used this model to modify the ellc transit tool. We used the modified ellc to generate the transit light curve for a deformed planet. Our model is parameterized by the Love number, hence for a given light curve we can derive the value of the Love number that best matches the observations. Results. We simulated the known cases of WASP-103b and WASP-121b which are expected to be highly deformed. Our analyses showed that instrumental precision ≤ 50 ppm/min is required to reliably estimate the Love number and detect tidal deformation. This precision can be achieved for WASP-103b in ∼40 transits using the Hubble Space Telescope and in ∼300 transits using the forthcoming CHEOPS instrument. However, fewer transits will be required for short-period planets that may be found around bright stars in the TESS and PLATO survey missions. The unprecedented precisions expected from PLATO and JWST can permit the detection of shape deformation with a single transit observation. However, the effects of instrumental and astrophysical noise must be well-considered as they can increase the number of transits required to reach the 50 ppm/min detection limit. We also show that improper modeling of limb darkening can act to bury signals related to shape of the planet thereby leading us to infer sphericity for a deformed planet. Therefore accurate determination of the limb darkening coefficients is required to confirm planet deformation.

show abstract

Untitled

Cited by 58 publications

References 30 publications

Transit timing variations in the WASP-4 planetary system

Transit timing variations in the WASP-4 planetary system

Physical properties and transmission spectrum of the WASP-74 planetary system from multiband photometry

Detectability of shape deformation in short-period exoplanets

Contact Info

Product

Resources

About