Explanipedia

Very long baseline interferometry detection of nearby (<100 pc) young stars Open

Sergio A. Dzib, Laurent Loinard, R. Launhardt, Jazmín Ordóñez-Toro · 2024

To increase the number of sources with very long baseline interferometry (VLBI) astrometry available for comparison with the Gaia results, we have observed 31 young stars with recently reported radio emission. These stars are all in the Ga…

Twenty-five Years of Accretion onto the Classical T Tauri Star TW Hya Open

Gregory J. Herczeg, Yuguang Chen, J.‐F. Donati, A. K. Dupree, Frederick M. Walter , et al. · 2023

Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest accret…

A resolved rotating disk wind from a young T Tauri star in the Bok globule CB 26 Open

R. Launhardt, Ya. N. Pavlyuchenkov, Vitaly Akimkin, A. Dutrey, F. Gueth , et al. · 2023

Context. The disk-outflow connection plays a key role in extracting excess angular momentum from a forming protostar. Although indications of jet rotation have been reported for a few objects, observational constraints of outflow rotation …

A resolved rotating disk wind from a young T Tauri star in the Bok globule CB26 Open

R. Launhardt, Ya. N. Pavlyuchenkov, Vitaly Akimkin, A. Dutrey, F. Gueth , et al. · 2023

The disk-outflow connection plays a key role in extracting excess angular momentum from a forming protostar. We have previously reported the discovery of a small molecular outflow from the edge-on T Tauri star in the Bok globule CB26 that …

Twenty-Five Years of Accretion onto the Classical T Tauri Star TW Hya Open

Gregory J. Herczeg, Yuguang Chen, J.‐F. Donati, A. K. Dupree, Frederick M. Walter , et al. · 2023

Accretion plays a central role in the physics that governs the evolution and dispersal of protoplanetary disks. The primary goal of this paper is to analyze the stability over time of the mass accretion rate onto TW Hya, the nearest accret…

Forbidden emission lines in protostellar outflows and jets with MUSE Open

Lizxandra Flores‐Rivera, Mario Flock, N. T. Kurtovic, B. Husemann, Andrea Banzatti , et al. · 2023

Context . Forbidden emission lines in protoplanetary disks are a key diagnostic in studies of the evolution of the disk and the host star. They signal potential disk accretion or wind, outflow, or jet ejection processes of the material tha…

ISPY-NACO Imaging Survey for Planets around Young stars. The demographics of forming planets embedded in protoplanetary disks Open

Gabriele Cugno, Timothy D. Pearce, R. Launhardt, Markus. J. Bonse, Jie. Ma , et al. · 2022

We present the statistical analysis of a subsample of 45 young stars surrounded by protoplanetary disks (PPDs). This is the largest imaging survey uniquely focused on PPDs to date. Our goal is to search for young forming companions embedde…

ISPY: NACO Imaging Survey for Planets around Young stars Open

Gabriele Cugno, Tim D. Pearce, R. Launhardt, Markus J. Bonse, Jie Ma , et al. · 2022

Context. Planet formation is a frequent process, but little observational constraints exist about the mechanisms involved, especially for giant planets at large separation. The NaCo-ISPY large program is a 120 night L ′-band direct imaging…

Radial velocity survey for planets around young stars (RVSPY) Open

O. V. Zakhozhay, R. Launhardt, Trifon Trifonov, M. Kürster, S. Reffert , et al. · 2022

Aims. We aim to detect planetary companions to young stars with debris disks via the radial velocity method. Methods. We observed HD 114082 during April 2018–August 2022 as one of the targets of our RVSPY program (Radial Velocity Survey fo…

Radial Velocity Survey for Planets around Young stars (RVSPY) Open

O. V. Zakhozhay, R. Launhardt, André Müller, S. S. Brems, Paul Eigenthaler , et al. · 2022

Context. The occurrence rate and period distribution of (giant) planets around young stars is still not as well constrained as for older main-sequence stars. This is mostly due to the intrinsic activity-related complications and the avoida…

The JWST Early Release Science Program for the Direct Imaging and Spectroscopy of Exoplanetary Systems Open

Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Andrew Skemer, Beth Biller , et al. · 2022

The direct characterization of exoplanetary systems with high-contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins,…

The JWST Early Release Science Program for the Direct Imaging & Spectroscopy of Exoplanetary Systems Open

Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Andrew Skemer, Beth Biller , et al. · 2022

The direct characterization of exoplanetary systems with high contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins,…

Nonthermal Radio Continuum Emission from Young Nearby Stars Open

R. Launhardt, Laurent Loinard, Sergio A. Dzib, Jan Forbrich, Geoffrey C. Bower , et al. · 2022

Young and magnetically active low-mass stars often exhibit nonthermal coronal radio emission owing to the gyration of electrons in their magnetized chromospheres. This emission is easily detectable at centimeter wavelengths with the curren…

Planet populations inferred from debris discs Open

Tim D. Pearce, R. Launhardt, Robert Ostermann, Grant M. Kennedy, Mario Gennaro , et al. · 2022

We know little about the outermost exoplanets in planetary systems because our detection methods are insensitive to moderate-mass planets on wide orbits. However, debris discs can probe the outer-planet population because dynamical modelli…

ISPY -- NaCo Imaging Survey for Planets around Young stars. CenteR: the impact of centering and frame selection Open

N. Godoy, J. Olofsson, A. Bayo, A. Cheetham, R. Launhardt , et al. · 2021

Abridged: Direct imaging has made significant progress over the past decade leading to the detection of several giant planets. Observing strategies and data rates vary from instrument to instrument and wavelength, and can result in tens of…

Detecting life outside our solar system with a large high-contrast-imaging mission Open

I. A. G. Snellen, Frans Snik, Matthew A. Kenworthy, Simon Albrecht, G. Anglada‐Escudé , et al. · 2021

Unveiling wide-orbit companions to K-type stars in Sco-Cen withGaiaEDR3 Open

A. J. Bohn, C. Ginski, Matthew A. Kenworthy, Eric E. Mamajek, Tiffany Meshkat , et al. · 2021

Context. The detection of low-mass companions to stellar hosts is important for testing the formation scenarios of these systems. Companions at wide separations are particularly intriguing objects as they are easily accessible for variabil…

Unveiling wide-orbit companions to K-type stars in Sco-Cen with Gaia EDR3 Open

A. J. Bohn, C. Ginski, Matthew A. Kenworthy, Eric E. Mamajek, Tiffany Meshkat , et al. · 2021

Abbreviated. We aim to identify new low-mass companions to young stars using the astrometric measurements provided by the Gaia space mission and complementary VLT/SPHERE data. We identify companion candidates from a sample of K-type, pre-m…

ESA Voyage 2050 White Paper: Detecting life outside our solar system with a large high-contrast-imaging mission Open

I. A. G. Snellen, Simon Albrecht, G. Anglada‐Escudé, I. Baraffe, Pierre Baudoz , et al. · 2021

In this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a missio…

The A-shell star ϕ Leo revisited: its photospheric and circumstellar spectra Open

C. Eiroa, B. Montesinos, Isabel Rebollido, Th. Henning, R. Launhardt , et al. · 2021

Context. We previously suggested that variable red- and blueshifted absorption features observed in the Ca II K line towards the A-type shell star ϕ Leo are likely due to solid, comet-like bodies in the circumstellar (CS) environment. Aims…

The A-shell star Phi Leo revisited: its photospheric and circumstellar spectra Open

C. Eiroa, B. Montesinos, Isabel Rebollido, Th. Henning, R. Launhardt , et al. · 2021

Variable red- and blue-shifted absorption features observed in the Ca ii K line towards the A-type shell star $ϕ$ Leo have been suggested by us in a previous work to be likely due to solid, comet-like bodies in the circumstellar (CS) envir…

Detection of complex organic molecules in young starless core L1521E Open

Samantha Scibelli, Yancy L. Shirley, A. I. Vasyunin, R. Launhardt · 2021

Determining the level of chemical complexity within dense starless and gravitationally bound pre-stellar cores is crucial for constructing chemical models, which subsequently constrain the initial chemical conditions of star formation. We …

Limits on the presence of planets in systems with debris discs: HD 92945 and HD 107146 Open

D. Mesa, Sebastián Marino, M. Bonavita, C. Lazzoni, C. Fontanive , et al. · 2021

Recent observations of resolved cold debris discs at tens of au have revealed that gaps could be a common feature in these Kuiper-belt analogues. Such gaps could be evidence for the presence of planets within the gaps or closer in near the…

Limits on the presence of planets in systems with debris disks: HD 92945 and HD 107146 Open

D. Mesa, Sebastián Marino, M. Bonavita, C. Lazzoni, C. Fontanive , et al. · 2021

Recent observations of resolved cold debris disks at tens of au have revealed that gaps could be a common feature in these Kuiper belt analogues. Such gaps could be evidence for the presence of planets within the gaps or closer-in near the…

Radial Velocity Survey for Planets around Young stars RV-SPY Open

O. V. Zakhozhay, R. Launhardt, S. S. Brems, Trifon Trifonov, A. Müller , et al. · 2021

Planets are born in gaseous protoplanetary disks that surround young stars. Within only a few million years, protoplantary disks lose their gas due to accretion onto the star and newly formed planets, but also via disk winds. While we are …

LIStEN: L′ band Imaging Survey for Exoplanets in the North Open

A. Musso Barcucci, R. Launhardt, André Müller, Grant M. Kennedy, R. van Boekel , et al. · 2021

Context. Planetary systems and debris discs are natural by-products of the star formation process, and they affect each other. The direct imaging technique allows simultaneous imaging of both a companion and the circumstellar disc it resid…

Resolving the outer ring of HD 38206 using ALMA and constraining limits on planets in the system Open

Mark Booth, Michael Schulz, A. V. Krivov, Sebastián Marino, Tim D. Pearce , et al. · 2020

HD 38206 is an A0V star in the Columba association, hosting a debris disc first discovered by IRAS. Further observations by Spitzer and Herschel showed that the disc has two components, likely analogous to the asteroid and Kuiper belts of …

ISPY-NACO Imaging Survey for Planets around Young stars Open

R. Launhardt, Th. Henning, A. Quirrenbach, D. Ségransan, H. Avenhaus , et al. · 2020

Context. The occurrence rate of long-period ( a ≳ 50 au) giant planets around young stars is highly uncertain since it is not only governed by the protoplanetary disc structure and planet formation process, but also reflects both dynamical…

ISPY -- NACO Imaging Survey for Planets around Young stars: Survey description and results from the first 2.5 years of observations Open

R. Launhardt, Th. Henning, A. Quirrenbach, D. Ségransan, H. Avenhaus , et al. · 2020

The occurrence rate of long-period giant planets around young stars is highly uncertain since it is not only governed by the protoplanetary disc structure and planet formation process, but also reflects dynamical re-structuring processes a…

Detection of Hα emission from PZ Telescopii B using SPHERE/ZIMPOL Open

A. Musso Barcucci, Gabriele Cugno, R. Launhardt, André Müller, J. Szulágyi , et al. · 2019

H α is a powerful tracer of accretion and chromospheric activity, which has been detected in the case of young brown dwarfs and even recently in planetary mass companions (e.g. PDS70 b and c). H α detections and characterisation of brown d…

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