Giant tidal tails of helium escaping the hot Jupiter HAT-P-32 b

Zhoujian Zhang; Caroline V Morley; Michael Gully-Santiago; Morgan MacLeod; Antonija Oklopčić; Jessica Luna; Quang H Tran; Joe P Ninan; Suvrath Mahadevan; Daniel M Krolikowski; William D Cochran; Brendan P Bowler; Michael Endl; Gudmundur Stefánsson; Benjamin M Tofflemire; Andrew Vanderburg; Gregory R Zeimann

doi:10.1126/sciadv.adf8736

Giant tidal tails of helium escaping the hot Jupiter HAT-P-32 b

Sci Adv. 2023 Jun 9;9(23):eadf8736. doi: 10.1126/sciadv.adf8736. Epub 2023 Jun 7.

Authors

Zhoujian Zhang^{1

2}, Caroline V Morley², Michael Gully-Santiago², Morgan MacLeod³, Antonija Oklopčić⁴, Jessica Luna², Quang H Tran², Joe P Ninan⁵, Suvrath Mahadevan^{6

7

8}, Daniel M Krolikowski^{2

9}, William D Cochran¹⁰, Brendan P Bowler², Michael Endl¹¹, Gudmundur Stefánsson¹², Benjamin M Tofflemire², Andrew Vanderburg¹³, Gregory R Zeimann¹⁴

Affiliations

¹ Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
² Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA.
³ Center for Astrophysics, Harvard and Smithsonian, Cambridge, MA 02138, USA.
⁴ Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, Netherlands.
⁵ Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai, India.
⁶ Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802, USA.
⁷ Center for Exoplanets and Habitable Worlds, University Park, PA 16802, USA.
⁸ ETH-Zürich, Institute for Particle Physics and Astrophysics, Zürich, Switzerland.
⁹ Steward Observatory, The University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721, USA.
¹⁰ Center for Planetary Systems Habitability and McDonald Observatory, The University of Texas at Austin, Austin, TX 78730, USA.
¹¹ McDonald Observatory and the Department of Astronomy, The University of Texas at Austin, Austin, TX 78712, USA.
¹² Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA.
¹³ Department of Physics and Kavli Institute for Astrophysics and Space Research, MIT, Cambridge, MA 02139, USA.
¹⁴ Hobby-Eberly Telescope, The University of Texas at Austin, Austin, TX 78712, USA.

Abstract

Capturing planets in the act of losing their atmospheres provides rare opportunities to probe their evolution history. This analysis has been enabled by observations of the helium triplet at 10,833 angstrom, but past studies have focused on the narrow time window right around the planet's optical transit. We monitored the hot Jupiter HAT-P-32 b using high-resolution spectroscopy from the Hobby-Eberly Telescope covering the planet's full orbit. We detected helium escaping HAT-P-32 b at a 14σ significance,with extended leading and trailing tails spanning a projected length over 53 times the planet's radius. These tails are among the largest known structures associated with an exoplanet. We interpret our observations using three-dimensional hydrodynamic simulations, which predict Roche Lobe overflow with extended tails along the planet's orbital path.