MASS TRANSFER, TRANSITING STREAM, AND MAGNETOPAUSE IN CLOSE-IN EXOPLANETARY SYSTEMS WITH APPLICATIONS TO WASP-12

By D. Lai, C. Helling, E. V. D. van den Heuvel. 2010

95 citations recorded by the source corpus.

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 km s−1 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 Hubble Space Telescope observations of the WASP-12 system. The asymmetric disk produced by the accretion stream may also lead to time-dependent obscuration of the starlight and apparent earlier ingress. We also consider the interaction of the stellar wind with the planetary magnetosphere. Since the wind speed is subsonic/sub-Alfvénic 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.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/26f00431eefedbcc350714d7d6393796d0e7d29e

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In Astronomy and Astrophysics

1. J. Southworth
2. L. Kaltenegger
3. J. Winn
4. S. Udry
5. D. Queloz
6. D. Deming
7. F. Pepe
8. James R. A. Davenport

In Instrumentation

1. J. Southworth
2. J. Winn
3. S. Udry
4. F. Pepe
5. Damien Ségransan
6. D. Queloz
7. D. Deming
8. James R. A. Davenport

Citations in the corpus

• THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS (2011, unknown): “…(1.1 days; just outside its star’s Roche limit) and inflated radius (1.8 R J ) led to the prediction that it is tidally distorted (Ragozzine & Wolf 2009; Leconte et al. 2011; Budaj 2011), and undergoing Roche lobe overflow followed by accretion onto its host star (Li et al. 2010; Lai et al. 2010).”
• The Apparently Decaying Orbit of WASP-12b (2017, background): “The resulting mass loss process has been studied theoretically by Li et al. (2010), Lai et al. (2010), and Bisikalo et al. (2013).”
• THE MUSCLES TREASURY SURVEY. I. MOTIVATION AND OVERVIEW (2016, background): “…et al. 2013), with very few possible detections from low-frequency radio observations (Lecavelier des Etangs et al. 2013) and earlyingress measurements of NUV and optical transit light curves (Fossati et al. 2010; Lai et al. 2010; Vidotto et al. 2010; Llama et al. 2011; Cauley et al. 2015).”
• WASP-121 b: a hot Jupiter close to tidal disruption transiting an active F star (2015, background): “Being close to its Roche limit, WASP-121 b might be significantly deformed by the intense tidal forces it is subject to (e.g. Budaj 2011) and even lose some of its mass through Roche lobe overflow (e.g. Li et al. 2010, Lai et al. 2010).”