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We present the results of a study to optimize the principal component analysis (PCA) algorithm for planet detection, a new algorithm complementing ADI and LOCI for increasing the contrast achievable next to a bright star. The stellar PSF is…

Earth and Planetary Astrophysics · Physics 2015-06-17 T. Meshkat , M. Kenworthy , S. P. Quanz , A. Amara

The $\sim$5 Myr PDS 70 is the only known system with protoplanets residing in the cavity of the circumstellar disk from which they formed, ideal for studying exoplanet formation and evolution within its natal environment. Here we report the…

The main goal of the EXOZODI survey is to detect and characterize circumstellar dust and to propose the first statistical study of exozodiacal disks in the near-infrared using telescopes in both hemispheres. For this purpose, Ertel et al.…

Solar and Stellar Astrophysics · Physics 2015-06-23 Lindsay Marion , Olivier Absil , Steve Ertel , Jean-Baptiste Le Bouquin , Denis Defrere

We describe a new method to achieve point spread function (PSF) subtractions for high- contrast imaging using Principal Component Analysis (PCA) that is applicable to both point sources or extended objects (disks). Assuming a library of…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Remi Soummer , Laurent Pueyo , James Larkin

Spectral differential imaging is an increasingly used technique for ground-based direct imaging searches for brown dwarf and planetary mass companions to stars. The technique takes advantage of absorption features that exist in these cool…

Astrophysics · Physics 2009-11-13 Markus Janson , Wolfgang Brandner , Thomas Henning

A photometric variability study of a sample of northern field stars, which previously classified as either PMS or Herbig Ae/Be objects, has been undertaken with the purpose of detecting {\delta} Scuti-type pulsations. Determination of…

Solar and Stellar Astrophysics · Physics 2014-09-05 D. Díaz-Fraile , E. Rodríguez , P. J. Amado

We re-analyze VLT/SPHERE-IRDIS K and H-band sparse aperture masking interferometry data of the transition disk HD 100546 observed in 2018 and 2021, respectively. We fit geometrical models to the closure phases extracted from both datasets.…

Eps Ind A is one of the nearest sun-like stars, located only 3.6 pc away. It is known to host a binary brown dwarf companion, Eps Ind Ba/Bb, at a large projected separation of 6.7", but radial velocity measurements imply that an additional,…

Earth and Planetary Astrophysics · Physics 2015-05-13 M. Janson , D. Apai , M. Zechmeister , W. Brandner , M. Kuerster , M. Kasper , S. Reffert , M. Endl , D. Lafreniere , K. Geissler , S. Hippler , Th. Henning

Aims: We want to detect and quantify observables related to accretion processes occurring locally in circumstellar disks, which could be attributed to young forming planets. We focus on objects known to host protoplanet candidates and/or…

Radio Frequency Interference (RFI) increasingly contaminates the radio astronomy spectrum, often exceeding astronomical signal amplitudes by 50-70 dB. Reliable detection and mitigation are therefore essential for studies of faint transient…

Instrumentation and Methods for Astrophysics · Physics 2026-05-08 Natalia A. Schmid , Sasanka Katreddi , Yechan Kweon

Spectro-astrometry is used to investigate the low velocity component (LVC) of the optical forbidden emission from the T Tauri stars RU Lupi and AS 205 N. Both stars also have high velocity forbidden emission (HVC) which is tracing a jet.…

Solar and Stellar Astrophysics · Physics 2021-06-02 E. T Whelan , I. Pascucci , U. Gorti , S. Edwards , R. D. Alexander , M. F. Sterzik , C. Melo

Reference-star differential imaging (RDI) is a promising technique in high-contrast imaging that is thought to be more sensitive to exoplanets and disks than angular differential imaging (ADI) at short angular separations (i.e., <0.3").…

Aims: We aim at detecting and characterizing the main-sequence companion of the Cepheid AX Cir ($P_\mathrm{orb} \sim $ 18 yrs). The long-term objective is to estimate the mass of both components and the distance to the system. Methods: We…

Solar and Stellar Astrophysics · Physics 2015-06-18 A. Gallenne , A. Mérand , P. Kervella , J. Breitfelder , J. -B. Le Bouquin , J. D. Monnier , W. Gieren , B. Pilecki , G. Pietrzyński

High-contrast imaging (HCI) is a technique designed to observe faint signals near bright sources, such as exoplanets and circumstellar disks. The primary challenge in revealing the faint circumstellar signal near a star is the presence of…

Earth and Planetary Astrophysics · Physics 2024-08-21 Sandrine Juillard , Valentin Christiaens , Olivier Absil , Sophia Stasevic , Julien Milli

We study a possibility to detect signatures of brown dwarf companions in a circumstellar disc based on spectral energy distributions (SED). We present the results of SED simulations for a system with a 0.8 $M_{\odot}$ central object and a…

Earth and Planetary Astrophysics · Physics 2017-04-12 Olga V. Zakhozhay

We identify delta Scuti pulsators amongst members of the recently-discovered Cep--Her Complex using light curves from the Transiting Exoplanet Survey Satellite (TESS). We use Gaia colours and magnitudes to isolate a subsample of provisional…

Solar and Stellar Astrophysics · Physics 2024-10-10 Simon J. Murphy , Timothy R. Bedding , Anuj Gautam , Ronan P. Kerr , Prasad Mani

V1247 Orionis harbours a pre-transitional disc with a partially cleared gap. Earlier interferometric and polarimetric observations revealed strong asymmetries both in the gap region and in the outer disc. The presence of a companion was…

Current detection methods of planetary companions do not allow retrieving their spectral information properties. The method of Differential Interferometry has the potential to complement such information by comparing interferometric…

Studying young protoplanetary disks is essential for understanding planet formation, but traditional angular differential imaging can introduce self-subtraction artefacts that hinder interpretation of small-scale structures. We present…

In this paper, we study the feasibility of obtaining near-infrared spectra of bright extrasolar planets with the 2nd generation VLTI Spectro-Imager instrument (VSI), which has the required angular resolution to resolve nearby hot Extrasolar…

Astrophysics · Physics 2009-11-13 S. Renard , O. Absil , J. -P. Berger , X. Bonfils , T. Forveille , F. Malbet