New analytical expressions of the Rossiter-McLaughlin effect adapted to different observation techniques

Boué, G.; Montalto, M.; Boisse, I.; Oshagh, M.; Santos, N. C.

doi:10.1051/0004-6361/201220146

Cited by 70 publications

(99 citation statements)

References 30 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We plot here the TRES multiorder RVs against the expected RossiterMcLaughlin model, based on the best-fit geometry from our global analysis. The Rossiter-McLaughlin signal is modeled using the ARoME library (Boué et al 2013). We show these data simply to confirm the consistency with the Doppler tomographic modeling; the in-transit velocities were not incorporated in the global modeling to avoid double-counting this information.…”

Section: Discussionmentioning

confidence: 71%

KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early A Star HD 185603

Lund

Rodriguez

Zhou

et al. 2017

View full text Add to dashboard Cite

We report the discovery of KELT-20b, a hot Jupiter transiting a V 7.6 early A star, HD 185603, with an orbital period of P 3.47  days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we infer that KELT-20 is a rapidly rotating ) . We place a 3s upper limit of M 3.5 J on the mass of the planet. Doppler tomographic 1 measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star ( 3 . 4 2 . 1 l =    ). The inclination of the star is constrained to I 24 . 4 155 . 6 *  < <  , implying a three-dimensional spin-orbit alignment of 1 . 3 69 . 8 y  < <  . KELT-20b receives an insolation flux of 8 10 erg s cm 9 1 2´--, implying an equilibrium temperature of of ∼2250 K, assuming zero albedo and complete heat redistribution. Due to the high stellar T eff , KELT-20b also receives an ultraviolet (wavelength d 91.2  nm) insolation flux of 9.1 10 erg s cm 4 1 2´--, possibly indicating significant atmospheric ablation. Together with WASP-33, Kepler-13 A, HAT-P-57, KELT-17, and KELT-9, KELT-20 is the sixth A star host of a transiting giant planet, and the thirdbrightest host (in V ) of a transiting planet.

show abstract

Section: Discussionmentioning

confidence: 71%

KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early A Star HD 185603

Lund

Rodriguez

Zhou

et al. 2017

View full text Add to dashboard Cite

show abstract

“…For the implications of this characteristic on the case of RossiterMacLaughlin measurements, the interested reader is referred to Boué et al (2013). This is a point to keep in mind when comparing the results obtained here with those obtained for RVs acquired with the iodine cell technique (e.g.…”

Section: Discussionmentioning

confidence: 84%

Line-profile variations in radial-velocity measurements

Figueira

Santos

Pepe

et al. 2013

A&A

Self Cite

112

View full text Add to dashboard Cite

Aims. We introduce two methods to identify false-positive planetary signals in the context of radial-velocity exoplanet searches. The first is the bi-Gaussian cross-correlation function fitting (and monitoring of the parameters derived from it), and the second is the measurement of asymmetry in radial-velocity spectral line information content, V asy . We assess the usefulness of each of these methods by comparing their results with those delivered by current indicators. Methods. We make a systematic analysis of the most used common line profile diagnosis, Bisector Inverse Slope and Velocity Span, along with the two proposed ones. We evaluate all these diagnosis methods following a set of well-defined common criteria and using both simulated and real data. We apply them to simulated cross-correlation functions that are created with the program SOAP and which are affected by the presence of stellar spots. We consider different spot properties on stars with different rotation profiles and simulate observations as obtained with high-resolution spectrographs. We then apply our methodology to real cross-correlation functions, which are computed from HARPS spectra, for stars with a signal originating in activity (thus spots) and for those with a signal rooted on a planet. Results. We demonstrate that the bi-Gaussian method allows a more precise characterization of the deformation of line profiles than the standard bisector inverse slope. The calculation of the deformation indicator is simpler and its interpretation more straightforward. More importantly, its amplitude can be up to 30% larger than that of the bisector span, allowing the detection of smaller-amplitude correlations with radial-velocity variations. However, a particular parametrization of the bisector inverse slope is shown to be more efficient on high-signal-to-noise data than both the standard bisector and the bi-Gaussian. The results of the V asy method show that this indicator is more effective than any of the previous ones, being correlated with the radial-velocity with more significance for signals resulting from a line deformation. Moreover, it provides a qualitative advantage over the bisector, showing significant correlations with RV for active stars for which bisector analysis is inconclusive. Conclusions. We show that the two indicators discussed here should be considered as standard tests to check for the planetary nature of a radial-velocity signal. We encourage the usage of different diagnosis as a way of characterizing the often elusive line profile deformations.

show abstract

“…Unfortunately, the Rossiter-McLaughlin effect is not detected. We also try to model the Rossiter-McLaughlin effect with the implementation of Boué et al (2013) but results are not conclusive either. According to Winn (2010), we can expect to observe a maximum amplitude of the RV anomaly ∆V RM ∼ 4 × 10 −3 × V sin i ∼ 12 m s −1 considering a maximum projected rotational velocity of 3 km s −1 .…”

Section: Global Analysismentioning

confidence: 99%

A global analysis ofSpitzerand new HARPS data confirms the loneliness and metal-richness of GJ 436 b

Lanotte

Gillon

Demory

et al. 2014

A&A

130

135

View full text Add to dashboard Cite

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims. We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods. We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 µm. Adding the high-precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar effects on the flux variation.Results. We present a refined radius estimate of R P = 4.10 ± 0.16 R ⊕ , mass M P = 25.4 ± 2.1 M ⊕ , and eccentricity e = 0.162 ± 0.004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 µm that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 µm that are shallower than in previous works, in particular at 3.6 µm. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO 2 , although perhaps less than previously thought. We could not detect a significant orbital modulation in the 8 µm phase curve. We find no evidence of a potential planetary companion, stellar activity, or a stellar spin-orbit misalignment. Conclusions. Recent theoretical models invoking high-metallicity atmospheres for warm Neptunes are a reasonable match to our results, but we encourage new modelling efforts based on our revised data. Future observations covering a wide wavelength range of GJ 436b and other Neptune-class exoplanets will further illuminate their atmosphere properties, whilst future accurate radial velocity measurements might explain the eccentricity.

show abstract

New analytical expressions of the Rossiter-McLaughlin effect adapted to different observation techniques

Cited by 70 publications

References 30 publications

KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early A Star HD 185603

KELT-20b: A Giant Planet with a Period of P ∼ 3.5 days Transiting the V ∼ 7.6 Early A Star HD 185603

Line-profile variations in radial-velocity measurements

A global analysis ofSpitzerand new HARPS data confirms the loneliness and metal-richness of GJ 436 b

Contact Info

Product

Resources

About