Related papers: An extremely low-density and temperate giant exopl…
The census of known exoplanets exhibits a variety of physical parameters, including densities that are measured to span the range from less dense than styrofoam to more dense than iron. These densities represent a large diversity of…
Moons orbiting exoplanets ("exomoons") may hold clues about planet formation, migration, and habitability. In this work, we investigate the plausibility of exomoons orbiting the temperate ($T_\text{eq}=294$ K) giant ($R = 9.2$ R$_\oplus$)…
We present a near-infrared transmission spectrum of the long period (P=542 days), temperate ($T_{eq}$=294 K) giant planet HIP 41378 f obtained with the Wide-Field Camera 3 (WFC3) instrument aboard the Hubble Space Telescope (HST). With a…
The Kepler mission has revealed a great diversity of planetary systems and architectures, but most of the planets discovered by Kepler orbit faint stars. Using new data from the K2 mission, we present the discovery of a five planet system…
HIP 41378 f is a temperate $9.2\pm0.1 R_{\oplus}$ planet with period of 542.08 days and an extremely low density of $0.09\pm0.02$ g cm$^{-3}$. It transits the bright star HIP 41378 (V=8.93), making it an exciting target for atmospheric…
The best-characterized exoplanets to date are planets on close-in transiting orbits around their host stars. The high level of irradiation and transiting geometry of these objects make them ideal targets for atmospheric investigations.…
HIP 41378 f is a sub-Neptune exoplanet with an anomalously low density. Its long orbital period and deep transit make it an ideal candidate for detecting oblateness photometrically. We present a new cross-platform, GPU-enabled code…
Gas giants transiting bright nearby stars provide crucial insights into planetary system formation and evolution mechanisms. Most of these planets exhibit certain average characteristics, serving as benchmarks for our understanding of…
Planets in close orbits around their host stars are subject to strong irradiation. High-energy irradiation, originating from the stellar corona and chromosphere, is mainly responsible for the evaporation of exoplanetary atmospheres. We have…
Exoplanetary science is among the fastest evolving fields of today's astronomical research. Ground-based planet-hunting surveys alongside dedicated space missions (Kepler, CoRoT) are delivering an ever-increasing number of exoplanets, now…
The amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. Of the thousands of extra-solar planets now known, only four giant planets have been found that transit hot,…
The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare…
We present new observations of the multi-planet system HIP~41378, a bright star ($V$ = 8.9, $K_s$ = 7.7) with five known transiting planets. Observations in Campaign 5 of the K2 mission showed multiple transits of two Neptune-sized bodies…
In 2015, K2 observations of the bright (V = 8.9, K = 7.7) star HIP 41378 revealed a rich system of at least five transiting exoplanets, ranging in size from super-Earths to gas giants. The 2015 K2 observations only spanned 74.8 days, and…
Atmospheric characterization is key to understanding exoplanetary systems, offering insights into the planets current and past conditions. By analyzing key lines like H alpha and the He I triplet, we can trace the evolution of planets…
Highly-irradiated giant exoplanets known as "ultra-hot Jupiters" are anticipated to exhibit large variations of atmospheric temperature and chemistry as a function of longitude, latitude, and altitude. Previous observations have hinted at…
The K2-33 planetary system hosts one transiting ~5 R_E planet orbiting the young M-type host star. The planet's mass is still unknown, with an estimated upper limit of 5.4 M_J. The extreme youth of the system (<20 Myr) gives the…
The presence of rings around a transiting planet can cause its radius to be overestimated and lead to an underestimation of its density if the mass is known. We employ a Bayesian framework to show that the anomalously low density…
High-contrast near-infrared imaging of the nearby star HR 8799 has shown three giant planets. Such images were possible due to the wide orbits (> 25 AU) and youth (< 100 Myr) of the imaged planets, which are still hot and bright as they…
With over 1800 planets discovered outside of the Solar System in the past two decades, the field of exoplanetology has broadened our perspective on planetary systems. Research priorities are now moving from planet detection to planet…