HST/STIS analysis of the first main sequence pulsar CU Virginis
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F19%3A00107424" target="_blank" >RIV/00216224:14310/19:00107424 - isvavai.cz</a>
Result on the web
<a href="https://www.aanda.org/articles/aa/abs/2019/05/aa34937-18/aa34937-18.html" target="_blank" >https://www.aanda.org/articles/aa/abs/2019/05/aa34937-18/aa34937-18.html</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1051/0004-6361/201834937" target="_blank" >10.1051/0004-6361/201834937</a>
Alternative languages
Result language
angličtina
Original language name
HST/STIS analysis of the first main sequence pulsar CU Virginis
Original language description
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-circle dot 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.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
ASTRONOMY & ASTROPHYSICS
ISSN
1432-0746
e-ISSN
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Volume of the periodical
625
Issue of the periodical within the volume
MAY 7 2019
Country of publishing house
FR - FRANCE
Number of pages
12
Pages from-to
1-12
UT code for WoS article
000467131000003
EID of the result in the Scopus database
2-s2.0-85089578780