The Atmospheric Diversity of Mini-Neptunes in Multi-planet Systems
Abstract
Mini-Neptunes, planets 2-4 times the size of the Earth, are an abundant outcome of planet formation and occur around more than a quarter of all stars — yet they are absent in the Solar System. Mini-Neptunes are believed to have thick, gaseous atmospheres, likely dominated by hydrogen, making them amenable to transmission spectroscopy observations using current facilities. We are conducting a Large Hubble program (GO-15333; PIs Crossfield & Kreidberg) to observe a sample of four favorable mini-Neptunes discovered in multi-planet systems by K2. Our observations employ the Wide Field Camera 3 spectrograph to target the 1.1-1.6 micron wavelength range, which encompasses strong H2O and CH4 absorption bands. With published transmission spectra currently available for only a small handful of mini-Neptunes, our survey will contribute significantly to what is known about this atmospheric class. We will present an update on the program results, focusing on the two targets for which data acquisition is near-complete: HD3167c (T~600K) and HD106315c (T~1000K).
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23524806M