WASP12 System WASP12 Magnitude 11 7 yellow dwarf

WASP-12 • Magnitude 11. 7 yellow dwarf o Sunlike – 1. 35 M☉ ,

WASP-12 b • Discovered 2008 • Extremely hot Jupiter o Orbital radius of 0.

WASP-12 b • Infrared spectroscopy predicts carbon-rich planet http: //www. nasa. gov/mission_pages/spitzer/multimedia/pia 13690. html

Presence of Exosphere • Multiple observations performed with HST • 2010 – evidence for

Possible Mechanisms • Tidal disruption o Eccentricity too low for WASP-12 b • Hydrodynamic

Detailed Examination • In addition to HST, ground observations with PIRATE, Faulkes North, and

Absorption Lines • Fe II (top) and Mg II (bottom) clear in data

Required Column Density • Absence of Mg II lines extremely anomalous • Column density

Estimates of Column Density • Estimate maximum column density using cylinder with height of

Estimates of Column Density • Better estimate would be using a torus of major

Magnetic Simulations • Interaction of stellar Parker wind with planetary gravity and magnetic field

References • • https: //arxiv. org/pdf/1005. 3656. pdf https: //arxiv. org/pdf/1301. 1860. pdf https:

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WASP-12

System

WASP-12 • Magnitude 11. 7 yellow dwarf o Sunlike – 1. 35 M☉ , 1. 6 R☉ o 2 companions, ~0. 5 M☉ each • 800 ly, in Auriga o RA 06: 30: 33. 0, Dec +29: 40: 20 wikisky. org

WASP-12 b • Discovered 2008 • Extremely hot Jupiter o Orbital radius of 0. 023 AU (essentially circular) o Period of 1. 09 days o 1. 7 RJ, 1. 4 MJ https: //astrobites. org/2015/04/29/and-the-saga-continuesthe-story-of-exoplanet-wasp-12 b/

WASP-12 b • Infrared spectroscopy predicts carbon-rich planet http: //www. nasa. gov/mission_pages/spitzer/multimedia/pia 13690. html

Observations

Presence of Exosphere • Multiple observations performed with HST • 2010 – evidence for extended cloud of gas ≥ Roche lobe o Absorption from metals in near UV

Possible Mechanisms • Tidal disruption o Eccentricity too low for WASP-12 b • Hydrodynamic blow-off from irradiation • Charge exchange creating cloud of hot H • Entrainment of material from stellar corona

Detailed Examination • In addition to HST, ground observations with PIRATE, Faulkes North, and James Gregory o All NUV • HST observations optimized for Mg II (doublet near 2800 Å) and Fe II (2586 Å) o Coverage overlaps for half total coverage • Occulting size in NUV significantly larger than optical size

Absorption Lines

Absorption Lines • Fe II (top) and Mg II (bottom) clear in data

Required Column Density • Absence of Mg II lines extremely anomalous • Column density from interstellar medium ~2 x 1016 /cm 2 o Order of magnitude less than would produce absorption profile similar to observation

Estimates of Column Density • Estimate maximum column density using cylinder with height of stellar diameter and orbital radius • Get 4 x 1021 /cm 2 o I get different result using their numbers:

Estimates of Column Density • Better estimate would be using a torus of major radius equal to orbital radius and minor radius equal to stellar radius

Magnetic Simulations • Interaction of stellar Parker wind with planetary gravity and magnetic field o No planetary outflows

References • • https: //arxiv. org/pdf/1005. 3656. pdf https: //arxiv. org/pdf/1301. 1860. pdf https: //arxiv. org/pdf/1303. 3375 v 1. pdf https: //arxiv. org/pdf/1512. 01555 v 1. pdf