Evolutionary track of the H/he envelope of the Sub-Neptunes and Super-Earths
Abstract
The observational detection of a localized reduction in the small planet occurrence rate, termed as "gap", is one of the most exciting and recent exoplanet discoveries. This gap appears to define a transition region in which sub-Neptune planets are believed to have lost their H/He envelop due to either photoevaporation or core powered loss mechanisms and transformed into bare cores. However, is still not clear the exactly location of the boundary between the planets that are still likely to hold an envelope (sub-Neptunes, SN) and the bare cores (super-Earths, T2). Here we investigate if the T2 planets are able to lose their primordial envelope during the first Myrs of their life. We find that photoevaporation can't explain the loss of the envelope derived if the T2 and SN have the same core mass. A second possibility is that these planets don't have the same core mass. In this case, we find that: 1) photoevaporation is able to strip off the primordial envelope fraction 2) there is an agreement between the primordial envelope fractions of the T2 and the SN at an age of 100Myr suggesting that these two groups are part of the same parent population.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23545803E