Published February 26, 2021 | Version v1
Poster Open

Probing exosphere of Neptune size planets around M-dwarf using He10830

  • 1. The Pennsylvania State University, University Park, PA, 16802, USA
  • 2. Princeton University, 4 Ivy Lane, Princeton, NJ 08540, USA
  • 3. Steward Observatory, University of Arizona, Tucson, Arizona 85721, USA
  • 4. University of California-Irvine, Irvine, California 92697, USA
  • 5. Carleton College, Northfield, Minnesota 55057, USA


Recently, resonant scattering absorption of meta-stable Helium atoms at 10830 Angstroms has been identified as a powerful probe to detect the extended exospheres from exoplanets. This near-infrared line is observable from the ground and unaffected by the interstellar medium, and has numerous advantages over conventional Ly alpha. The high spectral resolution observations of these meta-stable helium atoms from the exospheres enable us to study the irradiation environment as well as the structure of the outflow from the evaporating atmospheres in M-dwarf planets. In this poster we present our first detection of He10830 in the exosphere of a warm Neptune orbiting an M-dwarf, GJ 3470, using the Habitable-Zone Planet Finder (HPF). We also present our analysis of the outflow structure via line profile analysis, and the EUV irradiation environment on the planet from this detection.



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