Abstract
As an exoplanet orbits its host star it reflects and emits light,
forming a distinctive phase curve. By observing this light, we can study
the atmosphere and surface of distant planets. The planets in our Solar
System show a wide range of atmospheric phenomena, with stable wind
patterns, changing storms, and evolving anomalies. Brown dwarfs also
exhibit atmospheric variability. Such temporal variability in the
atmosphere of a giant exoplanet has not to date been observed. HAT-P-7 b
is an exoplanet with a known offset in the peak of its phase curve. Here
we present variations in the peak offset ranging between
-0.086+0.033-0.033 to 0.143+0.040-0.037 in phase, implying that the peak
brightness repeatedly shifts from one side of the planet's substellar
point to the other. The variability occurs on a timescale of tens to
hundreds of days. These shifts in brightness are indicative of
variability in the planet's atmosphere, and result from a changing
balance of thermal emission and reflected flux from the planet's
dayside. We suggest that variation in wind speed in the planetary
atmosphere, leading to variable cloud coverage on the dayside and a
changing energy balance, is capable of explaining the observed
variation.
Original language | English |
---|---|
Pages (from-to) | 4 |
Journal | Nature Astronomy |
Volume | 1 |
DOIs | |
Publication status | Published - 01 Dec 2016 |
Fingerprint
Dive into the research topics of 'Variability in the atmosphere of the hot giant planet HAT-P-7 b'. Together they form a unique fingerprint.Profiles
-
Ernst de Mooij
- School of Mathematics and Physics - Senior Lecturer
- Astrophysics Research Centre (ARC)
Person: Academic