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Related papers: The HD 98800 quadruple pre-main sequence system. T…

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Context: Inferring the likely formation channel of giant exoplanets and brown dwarf companions from orbital and atmospheric observables remains a formidable challenge. Further and more precise directly measured dynamical masses of these…

[Abridged] We present the first direct comparison of the distribution of the gas, as traced by the [OI] 6300 AA emission, and the dust, as traced by the 10 micron emission, in the protoplanetary disk around three intermediate-mass stars: HD…

The Ap star HD3980 appears to be a promising roAp candidate based on its fundamental parameters, leading us to search for rapid pulsations with the VLT UV-Visual Echelle Spectrograph (UVES). A precise Hipparcos parallax and estimated…

Astrophysics · Physics 2009-11-13 V. G. Elkin , D. W. Kurtz , L. M. Freyhammer , S. Hubrig , G. Mathys

We are conducting a comprehensive investigation of V815 Her using photometric and spectroscopic data to understand the origin of the activity and what influences it in the short and long term. Using TESS photometry we performed light curve…

Solar and Stellar Astrophysics · Physics 2024-01-09 Zs. Kovari , K. G. Strassmeier , L. Kriskovics , K. Olah , T. Borkovits , A. Radvanyi , T. Granzer , B. Seli , K. Vida , M. Weber

Context: Stellar evolution models are highly dependent on accurate mass estimates, especially for high-mass stars in the early stages of evolution. The most direct method for obtaining model-independent masses is derivation from the orbit…

A system of four super-Jupiter planets around HR 8799 is the first multi-planet configuration discovered via the direct imaging technique. Despite over decade of research, the system's architecture remains not fully resolved. The main…

Earth and Planetary Astrophysics · Physics 2020-10-28 Krzysztof Gozdziewski , Cezary Migaszewski

In order to investigate the Galactic-scale environmental effects on the evolution of protoplanetary disks, we explored the near-infrared (NIR) disk fraction of the Quartet cluster, which is a young cluster in the innermost Galactic disk at…

Solar and Stellar Astrophysics · Physics 2016-02-17 Chikako Yasui , Naoto Kobayashi , Satoshi Hamano , Sohei Kondo , Natsuko Izumi , Masao Saito , Alan T. Tokunaga

delta Velorum is a nearby (24pc) triple stellar system, containing a close, eclipsing binary (Aa, Ab) discovered in 2000. Multiple systems provide an opportunity to determine the set of fundamental parameters (mass, luminosity, size and…

Astrophysics · Physics 2009-11-13 A. Kellerer , M. G. Petr-Gotzens , P. Kervella , V. Coude du Foresto

We present the latest and most precise characterization of the architecture for the ancient ($\approx 11$ Gyr) Kepler-444 system, which is composed of a K0 primary star (Kepler-444 A) hosting five transiting planets, and a tight M-type…

We investigate the structure of the O-type binary system HD 48099 by measuring linear polarization that arises due to light scattering process. Linear polarization measurements of HD 48099 in the B, V and R passbands with the high-precision…

Solar and Stellar Astrophysics · Physics 2016-06-02 A. Berdyugin , V. Piirola , S. Sadegi , S. Tsygankov , T. Sakanoi , M. Kagitani , M. Yoneda , S. Okano , J. Poutanen

We have carried out 200,000 N-body simulations of three identical stellar embryos with masses from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions, while accreting using…

Solar and Stellar Astrophysics · Physics 2015-06-23 Bo Reipurth , Seppo Mikkola

Aims: Today, large ground-based instruments, like VISIR on the VLT, providing diffraction-limited (about 0.3 arcsec) images in the mid-infrared where strong PAH features appear enable us to see the flaring structure of the disks around…

Astrophysics · Physics 2007-05-23 Doucet , C. , Habart , E , Pantin , E. , Dullemond , C. , Lagage , P-O , Pinte , C. , Duchêne , G. , Ménard , F.

Brown dwarfs with known physical properties (e.g., age and mass) are essential for constraining models of the formation and evolution of substellar objects. We present new high-contrast imaging observations of the circumbinary brown dwarf…

Earth and Planetary Astrophysics · Physics 2025-03-10 Gabriel Weible , Kevin Wagner , Jordan Stone , Steve Ertel , Dániel Apai , Kaitlin Kratter , Jarron Leisenring

Benchmark brown dwarfs in wide binary systems are crucial for characterizing substellar objects and calibrating atmospheric and evolutionary models. However, brown dwarf benchmarks with subsolar metallicity, very cool temperatures, or…

A new class of pre-main sequence objects has been recently identified as pre-transitional disks. They present near-infrared excess coupled to a flux deficit at about 10 microns and a rising mid-infrared and far-infrared spectrum. These…

We have investigated the formation of a circumstellar wide-orbit gas giant planet in a multiple stellar system. We consider a model of orbital circularization for the core of a giant planet after it is scattered from an inner disk region by…

Earth and Planetary Astrophysics · Physics 2017-08-15 Arika Higuchi , Shigeru Ida

Using optical long baseline interferometry, we resolved for the first time the two wide components of HD167971, a candidate hierarchical triple system known to efficiently accelerate particles. Our multi-epoch VLTI observations provide…

Solar and Stellar Astrophysics · Physics 2015-06-04 M. De Becker , H. Sana , O. Absil , J. -B. Le Bouquin , R. Blomme

We present the most precise to date orbital and physical parameters of the well known short period (P=5.975 d), eccentric (e=0.3) double-lined spectroscopic binary BY Draconis, a prototype of a class of late-type, active, spotted flare…

Solar and Stellar Astrophysics · Physics 2015-05-30 K. G. Hełminiak , M. Konacki , M. W. Muterspaugh , S. E. Browne , A. W. Howard , S. R. Kulkarni

HIP96515A is a double-lined spectroscopic binary with a visual companion (HIP96515B) at 8.6 arcsec. It is included in the SACY catalog as a potential young star and classified as an eclipsing binary in the ASAS Catalog. We have analyzed…

Hot subdwarf (sdB) stars in binary systems with main-sequence (MS) companions provide valuable insights into mass transfer and envelope ejection processes in binary evolution. Their mass ratios, orbital periods, and stellar properties…

Solar and Stellar Astrophysics · Physics 2026-04-07 Jiangdan Li , Jianping Xiong , Jiao Li , Hai-Liang Chen , Hongwei Ge , Mingkuan Yang , Xuefei Chen , Zhanwen Han