TY - JOUR
T1 - Habitable evaporated cores
T2 - Transforming mini-Neptunes into super-earths in the habitable zones of M dwarfs
AU - Luger, R.
AU - Barnes, R.
AU - Lopez, E.
AU - Fortney, J.
AU - Jackson, B.
AU - Meadows, V.
N1 - Publisher Copyright:
© 2015, Mary Ann Liebert, Inc.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - We show that photoevaporation of small gaseous exoplanets ("mini-Neptunes") in the habitable zones of M dwarfs can remove several Earth masses of hydrogen and helium from these planets and transform them into potentially habitable worlds. We couple X-ray/extreme ultraviolet (XUV)-driven escape, thermal evolution, tidal evolution, and orbital migration to explore the types of systems that may harbor such "habitable evaporated cores" (HECs). We find that HECs are most likely to form from planets with ∼1 M solid cores with up to about 50% H/He by mass, though whether or not a given mini-Neptune forms a HEC is highly dependent on the early XUV evolution of the host star. As terrestrial planet formation around M dwarfs by accumulation of local material is likely to form planets that are small and dry, evaporation of small migrating mini-Neptunes could be one of the dominant formation mechanisms for volatile-rich Earths around these stars.
AB - We show that photoevaporation of small gaseous exoplanets ("mini-Neptunes") in the habitable zones of M dwarfs can remove several Earth masses of hydrogen and helium from these planets and transform them into potentially habitable worlds. We couple X-ray/extreme ultraviolet (XUV)-driven escape, thermal evolution, tidal evolution, and orbital migration to explore the types of systems that may harbor such "habitable evaporated cores" (HECs). We find that HECs are most likely to form from planets with ∼1 M solid cores with up to about 50% H/He by mass, though whether or not a given mini-Neptune forms a HEC is highly dependent on the early XUV evolution of the host star. As terrestrial planet formation around M dwarfs by accumulation of local material is likely to form planets that are small and dry, evaporation of small migrating mini-Neptunes could be one of the dominant formation mechanisms for volatile-rich Earths around these stars.
KW - 57-88.
KW - Astrobiology-Extrasolar terrestrial planets-Habitability-Planetary atmospheres-Tides. Astrobiology 15
UR - http://www.scopus.com/inward/record.url?scp=84921314309&partnerID=8YFLogxK
U2 - 10.1089/ast.2014.1215
DO - 10.1089/ast.2014.1215
M3 - Article
C2 - 25590532
AN - SCOPUS:84921314309
SN - 1531-1074
VL - 15
SP - 57
EP - 88
JO - Astrobiology
JF - Astrobiology
IS - 1
ER -