scholarly journals An update on the rotational period of the magnetic chemically peculiar star CU Virginis

2013 ◽  
Vol 431 (3) ◽  
pp. 2106-2110 ◽  
Author(s):  
Diane M. Pyper ◽  
Ian R. Stevens ◽  
Saul J. Adelman
Keyword(s):  
Rotational Period ◽  
Peculiar Star ◽  
Chemically Peculiar

Very High Resolution Ultraviolet Spectroscopy of a Chemically Peculiar Star: Results of the χ Lupi Pathfinder Project

1999 ◽  
Vol 117 (3) ◽  
pp. 1454-1470 ◽  
Author(s):  
David S. Leckrone ◽  
Charles R. Proffitt ◽  
Glenn M. Wahlgren ◽  
Sveneric G. Johansson ◽  
Tomas Brage
Keyword(s):  
High Resolution ◽  
Ultraviolet Spectroscopy ◽  
Peculiar Star ◽  
Chemically Peculiar ◽  
Very High

scholarly journals The Abundances of Cobalt and Nickel in the Atmosphere of 78 Vir (A2p SrCrEu)

2022 ◽  
Vol 6 (1) ◽  
pp. 9
Author(s):  
Richard Monier
Keyword(s):  
Convincing Evidence ◽  
Ultraviolet Spectrum ◽  
Rotational Period ◽  
Solar Abundance ◽  
Long Wavelength ◽  
Chemically Peculiar ◽  
Long Wave ◽  
Cobalt And Nickel

Abstract Cobalt and nickel abundances are rarely available for normal and Chemically Peculiar A stars because the strongest transitions of Co ii and Ni ii fall in the mid-UV. The abundances of cobalt and nickel are derived for 78 Vir using a mean mid-ultraviolet spectrum constructed by coadding 10 spectra collected with the Long Wave Prime and Long wavelength Redundant cameras over the 18 yr of the IUE mission. The strong transitions of Co ii at 2286.16 Å, 2307.86 Å, 2324.32 Å and 2580.33 Å and that of Ni ii et 2287.09 Å are present and more or less affected by blends. The least blended, λ 2286.16 Å, yields a mean overabundance of cobalt of 5 times the solar abundance, the Ni ii line at 2287.09 Å yields a 3 times solar overabundance. There is no convincing evidence that these lines varied in the spectra analyzed. The rotational period of 78 Vir estimated from its recent TESS lightcurve is 3.723 ± 0.055 days.

scholarly journals HST/STIS analysis of the first main sequence pulsar CU Virginis

2019 ◽  
Vol 625 ◽  
pp. A34 ◽  
Author(s):  
J. Krtička ◽  
Z. Mikulášek ◽  
G. W. Henry ◽  
J. Janík ◽  
O. Kochukhov ◽  
...  
Keyword(s):  
Radio Emission ◽  
Main Sequence ◽  
Flux Distribution ◽  
Mass Loss Rate ◽  
Rotational Period ◽  
Uv Spectrum ◽  
Chemically Peculiar ◽  
Peculiar Stars ◽  
Chemically Peculiar Stars

Context. CU Vir has been the first main sequence star that showed regular radio pulses that persist for decades, resembling the radio lighthouse of pulsars and interpreted as auroral radio emission similar to that found in planets. The star belongs to a rare group of magnetic chemically peculiar stars with variable rotational period. Aims. We study the ultraviolet (UV) spectrum of CU Vir obtained using STIS spectrograph onboard the Hubble Space Telescope (HST) to search for the source of radio emission and to test the model of the rotational period evolution. Methods. We used our own far-UV and visual photometric observations supplemented with the archival data to improve the parameters of the quasisinusoidal long-term variations of the rotational period. We predict the flux variations of CU Vir from surface abundance maps and compare these variations with UV flux distribution. We searched for wind, auroral, and interstellar lines in the spectra. Results. The UV and visual light curves display the same long-term period variations supporting their common origin. New updated abundance maps provide better agreement with the observed flux distribution. The upper limit of the wind mass-loss rate is about 10−12 M⊙ yr−1. We do not find any auroral lines. We find rotationally modulated variability of interstellar lines, which is most likely of instrumental origin. Conclusions. Our analysis supports the flux redistribution from far-UV to near-UV and visual domains originating in surface abundance spots as the main cause of the flux variability in chemically peculiar stars. Therefore, UV and optical variations are related and the structures leading to these variations are rigidly confined to the stellar surface. The radio emission of CU Vir is most likely powered by a very weak presumably purely metallic wind, which leaves no imprint in spectra.

Abundance analysis and searching for nonradial pulsations in the atmosphere of the chemically peculiar star HD 115708

2008 ◽  
Vol 34 (6) ◽  
pp. 413-422 ◽  
Author(s):  
E. A. Semenko ◽  
M. E. Sachkov ◽  
T. A. Ryabchikova ◽  
D. O. Kudryavtsev ◽  
N. E. Piskunov
Keyword(s):  
Peculiar Star ◽  
Chemically Peculiar

scholarly journals A search for rapid pulsations in the magnetic cool chemically peculiar star HD 3980★

2008 ◽  
Vol 390 (3) ◽  
pp. 1250-1257 ◽  
Author(s):  
V. G. Elkin ◽  
D. W. Kurtz ◽  
L. M. Freyhammer ◽  
S. Hubrig ◽  
G. Mathys
Keyword(s):  
Peculiar Star ◽  
Chemically Peculiar

scholarly journals Study of Inhomogeneities on the Surface of Magnetic CP Stars

1986 ◽  
Vol 90 ◽  
pp. 125-132
Author(s):  
V.L. Khokhlova
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Stokes Parameters ◽  
Abundance Distribution ◽  
Peculiar Star ◽  
Chemically Peculiar ◽  
Field Geometry

AbstractThe formulation and solution of the inverse problem to determine local Stokes parameters on the surface of a star, in particular magnetic chemically peculiar star, and hence to determine surface abundance distribution and magnetic field geometry is reviewed.

The Advanced Spectral Library (ASTRAL): Abundance Analysis of the Chemically Peculiar Star HR 465

2020 ◽  
Vol 899 (2) ◽  
pp. 166
Author(s):  
Krister E. Nielsen ◽  
Kenneth G. Carpenter ◽  
Gladys V. Kober ◽  
Glenn M. Wahlgren
Keyword(s):  
Spectral Library ◽  
Peculiar Star ◽  
Chemically Peculiar

scholarly journals A spectroscopic analysis of the chemically peculiar star HD 207561

2012 ◽  
Vol 424 (3) ◽  
pp. 2002-2008 ◽  
Author(s):  
S. Joshi ◽  
E. Semenko ◽  
P. Martinez ◽  
M. Sachkov ◽  
Y. C. Joshi ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Peculiar Star ◽  
Chemically Peculiar
Sign in / Sign up

Export Citation Format

Share Document