Related papers: HST/NICMOS detection of HR 8799 b in 1998

We present an open-source retrieval code named HELIOS-Retrieval (hereafter HELIOS-R), designed to obtain chemical abundances and temperature-pressure profiles from inverting the measured spectra of exoplanetary atmospheres. In the current…

We present direct imaging observations at wavelengths of 3.3, 3.8 (L',band), and 4.8 (M band) microns, for the planetary system surrounding HR 8799. All three planets are detected at L'. The c and d component are detected at 3.3 microns,…

Determining the atmospheric structure and chemical composition of an exoplanet remains a formidable goal. Fortunately, advancements in the study of exoplanets and their atmospheres have come in the form of direct imaging - spatially…

We have generated an extensive new suite of massive giant planet atmosphere models and used it to obtain fits to photometric data for the planets HR 8799b, c, and d. We consider a wide range of cloudy and cloud-free models. The cloudy…

We explore KLIP forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR 8799, using PyKLIP and show algorithm stability with varying KLIP parameters. We report new and re-reduced spectrophotometry of HR 8799 c,…

We derive improved system parameters for the HD 209458 system using a model that simultaneously fits both photometric transit and radial velocity observations. The photometry consists of previous Hubble Space Telescope STIS and FGS…

We present HST/NICMOS observations with 0.1" (15 AU) resolution of six young stellar objects in the Taurus star-formation region. The targets of our survey are three Class I IRAS sources (IRAS 04016+2610, IRAS 04248+2612, and IRAS…

High-contrast medium resolution spectroscopy has been used to detect molecules such as water and carbon monoxide in the atmospheres of gas giant exoplanets. In this work, we show how it can be used to derive radial velocity (RV)…

We present JWST Early Release Science (ERS) coronagraphic observations of the super-Jupiter exoplanet, HIP 65426 b, with the Near-Infrared Camera (NIRCam) from 2-5 $\mu$m, and with the Mid-Infrared Instrument (MIRI) from 11-16 $\mu$m. At a…

Atomic hydrogen escaping from the planet HD209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. However, the Space Telescope Imaging Spectrograph (STIS) used in previous observational…

Comparing chemical abundances of a planet and the host star reveals the origin and formation path. Stellar abundance is measured with high-resolution spectroscopy. Planet abundance, on the other hand, is usually inferred from low-resolution…

The system of four planets around HR8799 offers a unique opportunity to probe the physics and chemistry at play in the atmospheres of self-luminous young (~30 Myr) planets. We recently obtained new photometry of the four planets and…

L 98-59 is an M3V dwarf star that hosts three small (R < 1.6 Earth radii) planets. The host star is bright (K = 7.1) and nearby (10.6 pc), making the system a prime target for follow-up characterization with the Hubble Space Telescope (HST)…

A combination of high-resolution and wide-field imaging reveals two binary stars and one triple star system among the sample of the first 11 stars with planets detected by radial velocity variations. High resolution speckle or adaptive…

Aims. The aim is to derive accurate stellar distances and extinctions for young stars of our survey in the Galactic anticenter direction using the Str\"omgren photometric system. This will allow a detailed mapping of the stellar density and…

Astrometry, one of the oldest branches of astronomy, has been revolutionized by missions like Hipparcos and especially Gaia, which mapped billions of stars with extraordinary precision. However, challenges such as detecting Earth-like…

As part of the James Webb Space Telescope (JWST) Guaranteed Time Observation (GTO) program "Direct Imaging of YSOs" (program ID 1179), we use JWST NIRCam's direct imaging mode in F187N, F200W, F405N, and F410M to perform high contrast…

The young A0V star HR 4796A is host to a bright and narrow ring of dust, thought to originate in collisions between planetesimals within a belt analogous to the Solar System's Edgeworth-Kuiper belt. Here we present high spatial resolution…

The detection of emission lines associated with accretion processes is a direct method for studying how and where gas giant planets form, how young planets interact with their natal protoplanetary disk and how volatile delivery to their…

Inner regions of protoplanetary disks host many complex physical processes such as star-disk interactions, magnetic fields, planet formation, and the migration of new planets. To directly study this region requires milli-arcsecond angular…