Astrophysics - Earth and Planetary Astrophysics

Biosignatures of the Earth. I. Airborne spectropolarimetric detection of photosynthetic life

Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly …

Self-optimizing adaptive optics control with reinforcement learning for high-contrast imaging

Current and future high-contrast imaging instruments require extreme adaptive optics systems to reach contrasts necessary to directly imaged exoplanets. Telescope vibrations and the temporal error induced by the latency of the control loop limit the …

A MUSE view of the asymmetric jet from HD 163296

Context. Jets and outflows are thought to play important roles in regulating star formation and disk evolution. An important question is how the jets are launched. HD 163296 is a well- studied Herbig Ae star that hosts proto-planet candidates, a …

First light of a holographic aperture mask: Observation at the Keck OSIRIS Imager

We report on the design, construction, and commissioning of a prototype aperture masking technology implemented at the Keck OSIRIS Imager: the holographic aperture mask. Holographic aperture masking (HAM) aims at (i) increasing the throughput of …

The vector-apodizing phase plate coronagraph: design, current performance, and future development

Over the last decade, the vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8-m class telescopes. The vAPP is an geometric-phase patterned coronagraph that …

A survey of the linear polarization of directly imaged exoplanets and brown dwarf companions with SPHERE-IRDIS. First polarimetric detections revealing disks around DH Tau B and GSC 6214-210 B

Context. Young giant planets and brown dwarf companions emit near- infrared radiation that can be linearly polarized up to several percent. This polarization can reveal the presence of an (unresolved) circumsubstellar accretion disk, rotation-induced …

LOUPE: observing Earth from the Moon to prepare for detecting life on Earth-like exoplanets

LOUPE, the Lunar Observatory for Unresolved Polarimetry of the Earth, is a small, robust spectro-polarimeter for observing the Earth as an exoplanet. Detecting Earth-like planets in stellar habitable zones is one of the key challenges of modern …

Design of the life signature detection polarimeter LSDpol

Many biologically produced chiral molecules such as amino acids and sugars show a preference for left or right handedness (homochirality). Light reflected by biological materials such as algae and leaves therefore exhibits a small amount of circular …

Searching for proto-planets with MUSE

Context. Protoplanetary disks contain structures such as gaps, rings, and spirals, which are thought to be produced by the interaction between the disk and embedded protoplanets. However, only a few planet candidates are found orbiting within …

CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion

Context. Direct imaging provides a steady flow of newly discovered giant planets and brown dwarf companions. These multi-object systems can provide information about the formation of low-mass companions in wide orbits and/or help us to speculate …