Mass Transfer, Transiting Stream and Magnetopause in Close-in Exoplanetary Systems with Applications to WASP-12

Abstract

We study mass transfer by Roche lobe overflow in close-in exoplanetary systems. The planet's atmospheric gas passes through the inner Lagrangian point and flows along a narrow stream, accelerating to 100-$200\kms$ velocity before forming an accretion disk. We show that the cylinder-shaped accretion stream can have an area (projected in the plane of the sky) comparable to that of the planet and a significant optical depth to spectral line absorption. Such a "transiting cylinder" may produce an earlier ingress of the planet transit, as suggested by recent HST observations of the WASP-12 system. The asymmetric disk produced by the accretion stream may also lead to time-dependent obscuration of the star light and apparent earlier ingress. We also consider the interaction of the stellar wind with the planetary magnetosphere. Since the wind speed is subsonic/sub-Alfvenic and comparable to the orbital velocity of the planet, the head of the magnetopause lies eastward relative to the substellar line (the line joining the planet and the star). The gas around the magnetopause may, if sufficiently compressed, give rise to asymmetric ingress/egress during the planet transit, although more works are needed to evaluate this possibility.

6 pages with 2 figures. Accepted in ApJ. Small changes (add discussion on asymmetric disks)

References in corpus (3)

• Atmospheric Escape from Hot Jupiters
• Metals in the Exosphere of the Highly Irradiated Planet WASP-12b
• WASP-12b as a prolate, inflated and disrupting planet from tidal dissipation

Cited by in corpus (84)

• The MUSCLES Treasury Survey I: Motivation and Overview
• Near-UV Absorption, Chromospheric Activity, and Star-Planet Interactions in the WASP-12 system
• WASP-121 b: a hot Jupiter in a polar orbit and close to tidal disruption
• Thermal Phase Variations of WASP-12b: Defying Predictions
• The HST PanCET Program: Exospheric Mg II and Fe II in the Near-UV transmission spectrum of WASP-121b using Jitter Decorrelation
• Early UV Ingress in WASP-12b: Measuring Planetary Magnetic Fields
• The Apparently Decaying Orbit of WASP-12
• Simulating the escaping atmospheres of hot gas planets in the solar neighborhood
• The Orbit of WASP-12b is Decaying
• Classification of magnetized star--planet interactions: bow shocks, tails, and inspiraling flows
• 3D Gas Dynamic Simulation of the Interaction Between the Exoplanet WASP-12b and Its Host Star
• The long egress of GJ~436b's giant exosphere
• Catastrophic Evaporation of Rocky Planets
• Magnetically Controlled Outflows from Hot Jupiters
• Hot Jupiter Magnetospheres
• On the environment surrounding close-in exoplanets
• Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits
• The search for radio emission from the exoplanetary systems 55 Cancri, $\upsilon$ Andromedae, and $\tau$ Boötis using LOFAR beam-formed observations
• Stellar Winds on the Main-Sequence I: Wind Model
• On the diversity of magnetic interactions in close-in star-planet systems
• WASP-103b: a new planet at the edge of tidal disruption
• The shocking transit of WASP-12b: Modelling the observed early ingress in the near ultraviolet
• Absorbing gas around the WASP-12 planetary system
• Magnetohydrodynamic Simulations of Hot Jupiter Upper Atmospheres
• Warm Spitzer Photometry of the Transiting Exoplanets CoRoT-1 and CoRoT-2 at Secondary Eclipse
• Optical hydrogen absorption consistent with a thin bow shock leading the hot Jupiter HD 189733b
• Prospects for Detection of Exoplanet Magnetic Fields Through Bow-Shock Observations During Transits
• Tidally-driven Roche-Lobe Overflow of Hot Jupiters with MESA
• Exoplanet Transit Variability: Bow Shocks and Winds Around HD 189733b
• Decaying Orbit of the Hot Jupiter WASP-12b: Confirmation with TESS Observations
• Detection of Atmospheric Escape from Four Young Mini Neptunes
• Mass Loss from the Exoplanet WASP-12b Inferred from $\text{Spitzer}$ Phase Curves
• From Hot Jupiters to Super-Earths via Roche Lobe Overflow
• Transit Variability in Bow Shock-Hosting Planets
• Hydrogen and Sodium Absorption in the Optical Transmission Spectrum of WASP-12b
• A decade of H$\alpha$ transits for HD 189733 b: stellar activity versus absorption in the extended atmosphere
• Hubble Space Telescope observations of the NUV transit of WASP-12b
• Cloud property trends in hot and ultra-hot giant gas planets (WASP-43b, WASP-103b, WASP-121b, HAT-P-7b, and WASP-18b)
• H$\alpha$ and He I absorption in HAT-P-32 b observed with CARMENES -- Detection of Roche lobe overflow and mass loss
• Understanding WASP-12b
• Multi-site campaign for transit timing variations of WASP-12 b: possible detection of a long-period signal of planetary origin
• Transit of Exomoon Plasma Tori: New Diagnosis
• Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope
• Types of Gaseous Envelopes of "Hot Jupiter" Exoplanets
• High-precision photometry of WASP-12 b transits
• Investigation of the environment around close-in transiting exoplanets using CLOUDY
• Transiting the Sun: The impact of stellar activity on X-ray and ultraviolet transits
• Radio Observations of HD 80606 Near Planetary Periastron
• Photometric observation of HAT-P-16b in the near-UV
• Variation in the pre-transit Balmer line signal around the hot Jupiter HD 189733 b
• Near-UV and optical observations of the transiting exoplanet TrES-3b
• Shock formation around planets orbiting M-dwarf stars
• MOVES III. Simultaneous X-ray and ultraviolet observations unveiling the variable environment of the hot Jupiter HD 189733b
• Transmission photometry of WASP-12b: simultaneous measurement of the planetary radius in three bands
• Evaporation of Jupiter like planets orbiting extreme horizontal branch stars
• On possible types of magnetospheres of hot Jupiters
• The effect of ISM absorption on stellar activity measurements and its relevance for exoplanet studies
• Generation of a Circumstellar Gas Disk by Hot Jupiter WASP-12b
• Photo-evaporation of close-in gas giants orbiting around G and M stars
• Mass-Radius Relationships for Very Low Mass Gaseous Planets
• The Colorado Ultraviolet Transit Experiment (CUTE) Mission Overview
• Transmission spectroscopy of the lowest-density gas giant: metals and a potential extended outflow in HAT-P-67b
• Modelling atmospheric escape and MgII near-ultraviolet absorption of the highly irradiated hot Jupiter WASP-12b
• Near-UV transit photometry of HAT-P-32 b with the LBT: Silicate aerosols in the planetary atmosphere
• Transit Timing Variation of XO-3b: Evidence for Tidal Evolution of Hot Jupiter with High Eccentricity
• TASTE V. A new ground-based investigation of orbital decay in the ultra-hot Jupiter WASP-12b
• Signatures of Obliquity in Thermal Phase Curves of Hot Jupiters
• Magnetospheres of hot Jupiters: hydrodynamic models & ultraviolet absorption
• H-alpha Variability in PTFO8-8695 and the Possible Direct Detection of Emission from a 2 Million Year Old Evaporating Hot Jupiter
• Space environment and magnetospheric Poynting fluxes of the exoplanet $\tau$ Boötis b
• Magnetic effect on equilibrium tides and its influence on the orbital evolution of binary systems
• TESS Timings of 31 Hot Jupiters with Ephemeris Uncertainties
• Extrasolar giant magnetospheric response to steady-state stellar wind pressure at 10, 5, 1, and 0.2 AU
• UVMag: stellar formation, evolution, structure and environment with space UV and visible spectropolarimetry
• Reassessing Exoplanet Light Curves with a Thermal Model
• Planetary transits at radio wavelengths: secondary eclipses of hot Jupiter extended atmospheres
• WASP-12b: A Mass-Losing Extremely Hot Jupiter
• Stellar Coronal and Wind Models: Impact on Exoplanets
• Tidally distorted barytropes and their Roche limits, with application to WASP-12b
• The effects of stellar winds and magnetic fields on exoplanets
• Magnetohydrodynamic simulation assessment of a potential near-ultraviolet early ingress in WASP-189b
• Mass loss by atmospheric escape from extremely close-in planets
• Observational Signatures of Planetary Tidal Disruption Events Around Solar-Mass Stars
• Characterizing the WASP-4 system with TESS and radial velocity data: Constraints on the cause of the hot Jupiter's changing orbit and evidence of an outer planet