Search Publications

Medium-resolution spectrum of the exoplanet HIP 65426 b
DOI: 10.1051/0004-6361/202038914 Bibcode: 2021A&A...648A..59P

D'Orazi, V.; Boccaletti, A.; Lagrange, A. -M. +18 more

Medium-resolution integral-field spectrographs (IFS) coupled with adaptive-optics such as Keck/OSIRIS, VLT/MUSE, or SINFONI are appearing as a new avenue for enhancing the detection and characterization capabilities of young, gas giant exoplanets at large heliocentric distances (>5 au). We analyzed K-band VLT/SINFONI medium-resolution (Rλ<…

2021 Astronomy and Astrophysics
AKARI Gaia Hipparcos 50
Discovery of a directly imaged planet to the young solar analog YSES 2
DOI: 10.1051/0004-6361/202140508 Bibcode: 2021A&A...648A..73B

Mugrauer, Markus; Ginski, Christian; Kenworthy, Matthew A. +8 more

Context. To understand the origin and formation pathway of wide-orbit gas giant planets, it is necessary to expand the limited sample of these objects. The mass of exoplanets derived with spectrophotometry, however, varies strongly as a function of the age of the system and the mass of the primary star.
Aims: By selecting stars with similar a…

2021 Astronomy and Astrophysics
Gaia Hipparcos 36
The GAPS Programme at TNG. XXVIII. A pair of hot-Neptunes orbiting the young star TOI-942
DOI: 10.1051/0004-6361/202039042 Bibcode: 2021A&A...645A..71C

Baratella, M.; Mallonn, M.; Scandariato, G. +48 more

Context. Young stars and multi-planet systems are two types of primary objects that allow us to study, understand, and constrain planetary formation and evolution theories.
Aims: We validate the physical nature of two Neptune-sized planets transiting TOI-942 (TYC 5909-319-1), a previously unacknowledged young star (50-20+30

2021 Astronomy and Astrophysics
Gaia Hipparcos 32
Direct characterization of young giant exoplanets at high spectral resolution by coupling SPHERE and CRIRES+
DOI: 10.1051/0004-6361/202038517 Bibcode: 2021A&A...646A.150O

Reiners, A.; Lopez, M.; Costille, A. +19 more

Studies of atmospheres of directly imaged extrasolar planets with high-resolution spectrographs have shown that their characterization is predominantly limited by noise on the stellar halo at the location of the studied exoplanet. An instrumental combination of high-contrast imaging and high spectral resolution that suppresses this noise and resol…

2021 Astronomy and Astrophysics
Hipparcos 31
The SOPHIE search for northern extrasolar planets. XVII. A wealth of new objects: Six cool Jupiters, three brown dwarfs, and 16 low-mass binary stars
DOI: 10.1051/0004-6361/202140712 Bibcode: 2021A&A...651A..11D

Bouchy, F.; Deleuil, M.; Moutou, C. +30 more

Distinguishing classes within substellar objects and understanding their formation and evolution need larger samples of substellar companions such as exoplanets, brown dwarfs, and low-mass stars. In this paper, we look for substellar companions using radial velocity surveys of FGK stars with the SOPHIE spectrograph at the Observatoire de Haute-Pro…

2021 Astronomy and Astrophysics
Gaia Hipparcos 14
Astrometric radial velocities for nearby stars
DOI: 10.1051/0004-6361/202141344 Bibcode: 2021A&A...652A..45L

Lindegren, Lennart; Dravins, Dainis

Context. Under certain conditions, stellar radial velocities can be determined from astrometry, without any use of spectroscopy. This enables us to identify phenomena, other than the Doppler effect, that are displacing spectral lines.
Aims: The change of stellar proper motions over time (perspective acceleration) is used to determine radial v…

2021 Astronomy and Astrophysics
Gaia Hipparcos 13
How many suns are in the sky? A SPHERE multiplicity survey of exoplanet host stars. I. Four new close stellar companions including a white dwarf
DOI: 10.1051/0004-6361/202038964 Bibcode: 2021A&A...649A.156G

Ginski, C.; Mugrauer, M.; Vogt, N. +2 more


Aims: We are studying the influence of stellar multiplicity on exoplanet systems and, in particular, systems that have been detected via radial-velocity searches. We are specifically interested in the closest companions as they would have a strong influence on the evolution of the original planet-forming disks. In this study, we present new c…

2021 Astronomy and Astrophysics
Hipparcos 9
Properties of the Hyades, the eclipsing binary HD 27130, and the oscillating red giant ɛ Tauri
DOI: 10.1051/0004-6361/202039250 Bibcode: 2021A&A...645A..25B

Snellen, I. A. G.; Grundahl, F.; Fredslund Andersen, M. +21 more

Context. The derivation of accurate and precise masses and radii is possible for eclipsing binary stars, allowing for insights into their evolution. When residing in star clusters, they provide measurements of even greater precision, along with additional information on their properties. Asteroseismic investigations of solar-like oscillations offe…

2021 Astronomy and Astrophysics
Gaia Hipparcos 8
Deep transfer learning for the classification of variable sources
DOI: 10.1051/0004-6361/202140369 Bibcode: 2021A&A...653A..22K

Bailer-Jones, Coryn A. L.; Kim, Dae-Won; Yeo, Doyeob +1 more

Ongoing or upcoming surveys such as Gaia, ZTF, or LSST will observe the light curves of billions or more astronomical sources. This presents new challenges for identifying interesting and important types of variability. Collecting a sufficient amount of labeled data for training is difficult, especially in the early stages of a new survey. Here we…

2021 Astronomy and Astrophysics
Gaia Hipparcos 7
Precise radial velocities of giant stars. XV. Mysterious nearly periodic radial velocity variations in the eccentric binary ε Cygni
DOI: 10.1051/0004-6361/202040087 Bibcode: 2021A&A...647A.160H

Trifonov, Trifon; Reffert, Sabine; Lee, Man Hoi +10 more

Context. Using the Hamilton Échelle Spectrograph at Lick Observatory, we have obtained precise radial velocities (RVs) of a sample of 373 G- and K-giant stars over more than 12 yr, leading to the discovery of several single and multiple planetary systems. The RVs of the long-period (~53 yr) spectroscopic binary ε Cyg (HIP 102488) are found to exhi…

2021 Astronomy and Astrophysics
Gaia Hipparcos 6