References of "Ruffio, Jean-Baptiste"
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See detailDynamical Evidence of a Spiral Arm-driving Planet in the MWC 758 Protoplanetary Disk
Ren, Bin; Dong, Ruobing; van Holstein, Rob G. et al

in Astrophysical Journal (2020), 898

More than a dozen young stars host spiral arms in their surrounding protoplanetary disks. The excitation mechanisms of such arms are under debate. The two leading hypotheses—companion-disk interaction and ... [more ▼]

More than a dozen young stars host spiral arms in their surrounding protoplanetary disks. The excitation mechanisms of such arms are under debate. The two leading hypotheses—companion-disk interaction and gravitational instability (GI)—predict distinct motion for spirals. By imaging the MWC 758 spiral arm system at two epochs spanning ∼5 yr using the SPHERE instrument on the Very Large Telescope, we test the two hypotheses for the first time. We find that the pattern speeds of the spirals are not consistent with the GI origin. Our measurements further evince the existence of a faint "missing planet" driving the disk arms. The average spiral pattern speed is 0°22 ± 0°03 yr[SUP]-1[/SUP], pointing to a driver at ${172}_{-14}^{+18}$ au around a 1.9 M[SUB]☉[/SUB] central star if it is on a circular orbit. In addition, we witness time-varying shadowing effects on a global scale that are likely originating from an inner disk. [less ▲]

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See detailDeep Exploration of ɛ Eridani with Keck Ms-band Vortex Coronagraphy and Radial Velocities: Mass and Orbital Parameters of the Giant Exoplanet
Mawet, Dimitri; Hirsch, Lea; Lee, Eve J. et al

in Astronomical Journal (2019), 157

We present the most sensitive direct imaging and radial velocity (RV) exploration of ɛ Eridani to date. ɛ Eridani is an adolescent planetary system, reminiscent of the early solar system. It is surrounded ... [more ▼]

We present the most sensitive direct imaging and radial velocity (RV) exploration of ɛ Eridani to date. ɛ Eridani is an adolescent planetary system, reminiscent of the early solar system. It is surrounded by a prominent and complex debris disk that is likely stirred by one or several gas giant exoplanets. The discovery of the RV signature of a giant exoplanet was announced 15 yr ago, but has met with scrutiny due to possible confusion with stellar noise. We confirm the planet with a new compilation and analysis of precise RV data spanning 30 yr, and combine it with upper limits from our direct imaging search, the most sensitive ever performed. The deep images were taken in the Ms band (4.7 μm) with the vortex coronagraph recently installed in W.M. Keck Observatory’s infrared camera NIRC2, which opens a sensitive window for planet searches around nearby adolescent systems. The RV data and direct imaging upper limit maps were combined in an innovative joint Bayesian analysis, providing new constraints on the mass and orbital parameters of the elusive planet. ɛ Eridani b has a mass of {0.78}[SUB]-0.12[/SUB][SUP]+0.38[/SUP] M [SUB]Jup[/SUB] and is orbiting ɛ Eridani at about 3.48 ± 0.02 au with a period of 7.37 ± 0.07 yr. The eccentricity of ɛ Eridani b’s orbit is {0.07}[SUB]-0.05[/SUB][SUP]+0.06[/SUP], an order of magnitude smaller than early estimates and consistent with a circular orbit. We discuss our findings from the standpoint of planet–disk interactions and prospects for future detection and characterization with the James Webb Space Telescope. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted for this project by Caltech, the University of Hawai’i, the University of California, and NASA. [less ▲]

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