Related papers: On the detectability of star-planet interaction
Results of photometric surveys have brought to light the existence of a population of giant planets orbiting their host stars even closer than the hot Jupiters (HJ), with orbital periods below 3 days. The reason why radial velocity surveys…
Tidal interactions are one of the primary drivers of orbital evolution for massive planets with short orbital periods. Tidal dissipation within host stars can cause the orbits of such planets to decay. However, the mechanisms of tidal…
We investigate the formation of bow shocks around exoplanets as a result of the interaction of the planet with the coronal material of the host star, focusing on physical causes that can lead to temporal variations in the shock…
Detailed atmospheric characterization of exoplanets by transmission spectroscopy requires careful consideration of stellar surface inhomogeneities induced by starspots. This effect is particularly problematic for planetary systems around…
Exoplanet research is now target rich with a wide diversity of systems making it difficult for high demand observatories to undertake follow up observations over extended periods of time. We investigate the effectiveness of using 0.4m-class…
Interactions between stellar and planetary magnetic fields are expected to produce observable radio and optical signals modulated by their orbital periods, but direct detections remain elusive. We analyze 17 years of spectroscopic data of…
Ultra-hot Jupiters are gas giants that orbit so close to their host star that they are tidally locked, causing a permanent hot dayside and a cooler nightside. Signatures of their nonuniform atmospheres can be observed with high-resolution…
With a Jupiter-mass planet orbiting at a distance of only 0.031 AU, the active K2 dwarf HD 189733 is a potential candidate in which to study the magnetospheric interactions of a cool star with its recently-discovered close-orbiting giant…
Stellar activity has a particularly strong influence on planets at small orbital distances, such as close-in exoplanets. For such planets, we present two extreme cases of stellar variability, namely stellar coronal mass ejections and…
In the last decade, ground-based high-resolution spectroscopy (HRS) has emerged as a powerful method to probe exoplanet atmospheres both in transit and thermal emission. With HRS science now maturing to reveal these planet's thermal,…
We present new X-ray observations obtained with Chandra ACIS-S of the HD 189733 system, consisting of a K-type star orbited by a transiting Hot Jupiter and an M-type stellar companion. We report a detection of the planetary transit in soft…
The surface rotations of some red giants are so fast that they must have been spun up by tidal interaction with a close companion, either another star, a brown dwarf, or a planet. We focus here on the case of red giants that are spun up by…
Context: Transmission spectroscopy has become a prominent tool for characterizing the atmospheric properties on close-in transiting planets. Recent observations have revealed a remarkable diversity in exoplanet spectra, which show…
The TRAPPIST-1 planetary system represents an exceptional opportunity for the atmospheric characterization of temperate terrestrial exoplanets with the upcoming James Webb Space Telescope (JWST). Assessing the potential impact of stellar…
The study of exoplanetary atmospheres relies on detecting minute changes in the transit depth at different wavelengths. To date, a number of ground and space based instruments have been used to obtain transmission spectra of exoplanets in…
Most hot Jupiters are expected to spiral in towards their host stars due to transfering of the angular momentum of the orbital motion to the stellar spin. Their orbits can also precess due to planet-star interactions. Calculations show that…
We present Keck/KPIC high-resolution ($R\sim35,000$) $K$-band thermal emission spectroscopy of the ultra-hot Jupiter WASP-33b. The use of KPIC's single-mode fibers greatly improves both blaze and line-spread stabilities relative to slit…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital…
Ultra-hot Jupiters are perfect targets for transmission spectroscopy. However, their atmospheres feature strong spatial variations in temperature, chemistry, dynamics, cloud coverage, and scale height. This makes transit observations at…