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Related papers: The "Second Solar Spectrum" of the post-AGB binary…

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Binaries with circumbinary disks are commonly found among optically bright post-AGB stars. Although clearly linked to binary interaction processes, the formation, evolution and fate of these disks are still badly understood. Due to their…

Solar and Stellar Astrophysics · Physics 2014-11-11 M. Hillen , J. Menu , B. de Vries , H. Van Winckel , M. Min , G. D. Mulders , C. Gielen , T. Wevers , S. Regibo , T. Verhoelst

We present novel spectropolarimetric observations of the hydrogen H$\alpha$ line taken with the Z\"urich Imaging Polarimeter (ZIMPOL) at the Gregory Coud\'e Telescope of the Istituto Ricerche Solari Locarno (IRSOL). The linear polarization…

Solar and Stellar Astrophysics · Physics 2022-03-30 J. Jaume Bestard , J. Trujillo Bueno , M. Bianda , J. Štěpán , R. Ramelli

The application of high-resolution spectropolarimetry has led to major progress in understanding the magnetism and activity of late-type stars. During the last decade, magnetic fields have been discovered and mapped for many types of active…

Solar and Stellar Astrophysics · Physics 2015-05-27 O. Kochukhov , V. Makaganiuk , N. Piskunov , F. Snik , S. V. Jeffers , C. M. Johns-Krull , C. U. Keller , M. Rodenhuis , J. A. Valenti

Using the Hopkins Ultraviolet Telescope (HUT), we have obtained 850-1850 angstrom spectra of the magnetic cataclysmic variable star AM Her in the high state. These observations provide high time resolution spectra of AM Her in the FUV and…

Astrophysics · Physics 2009-10-31 Bradford W. Greeley , William P. Blair , Knox S. Long , John C. Raymond

We present RXTE observations of the eclipsing X-ray binary Hercules X-1 conducted during an anomalous low state. Data reduction reveals a light curve over 2.7 orbital cycles remarkably similar to optical and UV light curves which are…

This is a theoretical investigation on the formation of the linearly polarized line spectrum of ionized cerium in the sun. We calculate the scattering line polarization pattern emergent from a plane-parallel layer of Ce {\sc ii} atoms…

Astrophysics · Physics 2009-11-11 R. Manso Sainz , E. Landi Degl'Innocenti , J. Trujillo Bueno

There is a class of binary post-AGB stars that are surrounded by Keplerian disks and that often present outflows resulting from gas escaping from the disk. We present maps and complex models of 12CO and 13CO J=2-1 emission lines for four…

Solar and Stellar Astrophysics · Physics 2023-11-15 Iván Gallardo Cava

We report the discovery of a new AM Herculis binary (polar) as the optical counterpart of the soft X-ray source RX J1724.0+4114 detected during the ROSAT all-sky survey. The magnetic nature of this V~17 mag object is confirmed by…

Astrophysics · Physics 2009-10-30 Jochen Greiner , Robert Schwarz , Wolfgang Wenzel

In this paper we present a spectroscopic study of six double-lined binaries, five of which were recently discovered in a high-resolution spectroscopic survey of optical counterparts of stellar X-ray sources. Thanks to high-resolution…

Solar and Stellar Astrophysics · Physics 2022-07-08 A. Frasca , G. Catanzaro , I. Busà , P. Guillout , J. Alonso-Santiago , C. Ferrara , M. Giarrusso , M. Munari , F. Leone

Binarity is often invoked to explain peculiarities that can not be explained by the standard theory of stellar evolution. Detecting orbital motion via the Doppler effect is the best method to test binarity when direct imaging is not…

Solar and Stellar Astrophysics · Physics 2014-03-11 N. Gorlova , H. Van Winckel , J. Vos , R. H. Ostensen , A. Jorissen , S. Van Eck , N. Ikonnikova

We carried out high-sensitivity spectropolarimetric observations of the central star of the Red Rectangle proto-planetary nebula with the aim of constraining the mechanism that gives its biconical shape. The stellar light of the central…

Solar and Stellar Astrophysics · Physics 2015-06-23 M. J. Martinez Gonzalez , A. Asensio Ramos , R. Manso Sainz , R. L. M. Corradi , F. Leone

We report photopolarimetric observations of a new eclipsing polar (AM Herculis system) discovered in the Calan-Tololo survey. The photometry and polarimetry are modulated on a period of ~101 minutes. Circular polarization variations are…

Astrophysics · Physics 2016-08-30 Stephen B. Potter , Thomas Augusteijn , Claus Tappert

Recently AMS-02 collaboration publish their measurements of light cosmic-ray nuclei, including lithium, beryllium, boron, carbon and oxygen. All of them reveal a prominent excess above $\sim$ 200 GV, coinciding with proton and helium.…

High Energy Astrophysical Phenomena · Physics 2019-01-09 Wei Liu , Yu-hua Yao , Yi-Qing Guo

Second-generation circumbinary discs around evolved binary stars, such as post-Asymptotic Giant Branch (post-AGB) binaries, provide insights into poorly understood mechanisms of dust processing and disc evolution across diverse stellar…

Solar and Stellar Astrophysics · Physics 2025-10-01 Kateryna Andrych , Devika Kamath , Hans Van Wincke , Akke Corporaa , Toon De Prins , Daniel Price , Steve Ertel , Jacques Kluska

One of the greatest challenges in solar and stellar physics in coming years will be to observe the Second Solar Spectrum with a spatial resolution significantly better than 1 arcsec. This type of scattering polarization observations would…

Astrophysics · Physics 2009-11-13 Javier Trujillo Bueno , Nataliya Shchukina

We performed a highly sensitive search for magnetic fields on a large set of HgMn stars. With the aid of a new polarimeter attached to the HARPS spectrometer at the ESO 3.6m-telescope, we obtained high-quality circular polarization spectra…

We report on new simultaneous phase resolved spectroscopic and polarimetric observations of the polar (AM Herculis star) V834 Cen during a high state of accretion. Strong emission lines and high levels of variable circular and linear…

We present our recent results on mm-wave CO observations of proto-planetary nebulae. These include high-resolution interferometric maps of various CO lines in three well known bipolar PPNe: M1-92, M2-56 and OH231.8+4.2. The global…

Astrophysics · Physics 2007-05-23 J. Alcolea , V. Bujarrabal , A. Castro-Carrizo , C. Sanchez Contreras , R. Neri , J. Zweigle

We report for the first time the stellar atmospheric parameters for a a set of post-AGB stars classified by Suarez et al. (2006). The stellar spectra were taken from optical region, with low-resolution and have different spectral ranges. We…

Solar and Stellar Astrophysics · Physics 2018-06-20 R. E. Molina

We describe recent results for Sgr A*, M81* and other low luminosity active galactic nuclei. We have conducted linear and circular polarimetry over a frequency range of 1.4 to 230 GHz and detected a variety of phenomena. The polarization…

Astrophysics · Physics 2009-11-07 Geoffrey C. Bower