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Related papers: Recent Investigations on AA Doradus

200 papers

The zero-age main-sequence star AB Dor and the K dwarf component of the V471 Tau close binary have essentially identical rotation rates and spectral types. An analysis of their high resolution {\it Chandra} X-ray spectra reveals remarkably…

Astrophysics · Physics 2009-11-10 D. Garcia-Alvarez , J. J. Drake , L. Lin , V. L. Kashyap , B. Ball

We present time-series spectroscopy and photometry of Gaia DR2 6097540197980557440, a new deeply-eclipsing hot subdwarf B (sdB) + M dwarf (dM) binary. We discovered this object during the course of the Eclipsing Reflection Effect Binaries…

Solar and Stellar Astrophysics · Physics 2021-09-08 Kyle A. Corcoran , Brad N. Barlow , Veronika Schaffenroth , Uli Heber , Stephen Walser , Andreas Irgang

We present a second paper related to the analyses of high-dispersion spectroscopic observations of the magnetic cataclysmic variable AE Aquarii. We focus our efforts on the study of the emission lines and their radial velocities. We detect…

Solar and Stellar Astrophysics · Physics 2021-12-08 Sergio Ramirez , Juan Echevarria

We present 2271 radial velocity measurements taken on 118 single-line binary stars, taken over eight years with the CORALIE spectrograph. The binaries consist of F/G/K primaries and M-dwarf secondaries. They were initially discovered…

Gamma Doradus stars (hereafter gamma Dor stars) are gravity-mode pulsators of spectral type A or F. Such modes probe the deep stellar interior, offering a detailed fingerprint of their structure. Four-year high-precision space-based Kepler…

Investigating long series of spectral and photometric observations, we found that the orbital elements of epsilon Aur are subject to much larger uncertainties than usually believed. The H alpha emission is found to move basically with the F…

Solar and Stellar Astrophysics · Physics 2013-03-27 P. Harmanec , H. Božić , D. Korčáková , L. Kotková , P. Škoda , M. Šlechta , M. Švanda , V. Votruba , M. Wolf , P. Zasche , A. Henden , J. Ribeiro

We confirmed the binary nature of the Be star 7~Vul, derived a~more accurate spectroscopic orbit with an orbital period of (69.4212+/-0.0034) d, and improved the knowledge of the basic physical elements of the system. Analyzing available…

Solar and Stellar Astrophysics · Physics 2020-07-08 P. Harmanec , J. Lipták , P. Koubský , H. Božić , J. Labadie-Bartz , M. Šlechta , S. Yang , A. Harmanec

The transition from the L to the T spectral type of brown dwarfs is marked by a very rapid transition phase, remarkable brightening in the J-band and a higher binary frequency. Despite being an active area of inquiry, this transition regime…

Solar and Stellar Astrophysics · Physics 2015-05-18 M. B. Stumpf , W. Brandner , H. Bouy , Th. Henning , S. Hippler

This research paper has light curve modelling, spectroscopy, and detailed asteroseismic studies for five detached eclipsing binaries with a $\gamma$ Dor component that have been found so far by the sky surveys. The objective is to study the…

Solar and Stellar Astrophysics · Physics 2025-02-25 O. Cakirli , B. Hoyman , O. Ozdarcan , S. Bilir

AR Aur is a detached eclipsing binary containing two late-B stars which are chemically peculiar, on a circular orbit of period 4.135 d. The primary is a HgMn star which shows temporal changes in its chemical abundances and spectral line…

Solar and Stellar Astrophysics · Physics 2025-07-30 John Southworth

We report the discovery of an eclipsing companion to NLTT 41135, a nearby M5 dwarf that was already known to have a wider, slightly more massive common proper motion companion, NLTT 41136, at 2.4 arcsec separation. Analysis of…

We analyse the K2 short cadence data of the intermediate polar FO Aqr and provide accurate and updated orbital and spin periodicities. We additionally find small spin period changes as a function of orbital phase of ~0.02 seconds…

Solar and Stellar Astrophysics · Physics 2016-08-17 S. Scaringi , C. Knigge , T. J. Maccarone

The occurrence of planets in binary star systems has been investigated via a variety of techniques that sample a wide range of semi-major axes, but with a preponderance of such results applicable to planets with semi-major axes less than a…

Solar and Stellar Astrophysics · Physics 2015-06-22 B. Zuckerman

New CCD photometric light curves of short period (P=0.285d) eclipsing binary RW Dor are presented. The observations performed with the PROMPT-8 robotic telescope at CTIO in Chile from March 2015 to March 2017. The other eclipse timings were…

Straddling the traditional realms of the planets and the stars, objects below the edge of the main sequence have such unique properties, and are being discovered in such quantities, that one can rightly claim that a new field at the…

Astrophysics · Physics 2008-11-26 Adam Burrows , W. B. Hubbard , J. I. Lunine , James Liebert

Subdwarf A star (sdA) is a spectral classification given to objects showing H-rich spectra and sub-main sequence surface gravities, but effective temperature lower than the zero-age horizontal branch. Their evolutionary origin is an enigma.…

Solar and Stellar Astrophysics · Physics 2018-06-13 Ingrid Pelisoli , S. O. Kepler , D. Koester , B. G. Castanheira , A. D. Romero , L. Fraga

While the first binary post-AGB stars were serendipitously discovered, the distinct characteristics of their Spectral Energy Distribution (SED) allowed us to launch a more systematic search for binaries. We selected post-AGB objects which…

Evolutionary models for massive stars, accounting for rotational mixing effects, do not predict any core-processed material at the surface of B dwarfs with low rotational velocities. Contrary to theoretical expectations, we present a…

Astrophysics · Physics 2009-11-13 T. Morel , S. Hubrig , M. Briquet

We have found a very faint companion to the active solar analog HR 7672 (HD 190406; GJ 779; 15 Sge). Three epochs of high resolution imaging using adaptive optics (AO) at the Gemini-North and Keck II Telescopes demonstrate that HR 7672B is…

Analyses of very accurate CoRoT space photometry, past Johnson V photoelectric photometry and high-resolution \'echelle spectra led to the determination of improved and consistent fundamental stellar properties of both components of AU Mon.…