2019
HST/STIS analysis of the first main sequence pulsar CU Virginis
KRTIČKA, Jiří, Zdeněk MIKULÁŠEK, G.W. HENRY, Jan JANÍK, Oleg KOCHUKHOV et. al.Základní údaje
Originální název
HST/STIS analysis of the first main sequence pulsar CU Virginis
Autoři
KRTIČKA, Jiří (203 Česká republika, garant, domácí), Zdeněk MIKULÁŠEK (203 Česká republika, domácí), G.W. HENRY (840 Spojené státy), Jan JANÍK (203 Česká republika, domácí), Oleg KOCHUKHOV (752 Švédsko), Andrzej PIGULSKI (616 Polsko), P. LETO, Corado TRIGILIO, Iva KRTIČKOVÁ (203 Česká republika, domácí), Theresa LUFTINGER (40 Rakousko), Milan PRVÁK (203 Česká republika, domácí) a Adam TICHÝ (203 Česká republika, domácí)
Vydání
ASTRONOMY & ASTROPHYSICS, LES ULIS CEDEX A, EDP SCIENCES S A, 2019, 1432-0746
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Francie
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 5.636
Kód RIV
RIV/00216224:14310/19:00107424
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000467131000003
Klíčová slova anglicky
stars: chemically peculiar; stars: early-type; stars: variables: general; stars: individual: CU Vir
Štítky
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 29. 3. 2021 14:17, Mgr. Marie Šípková, DiS.
Anotace
V originále
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.
Návaznosti
GA16-01116S, projekt VaV |
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GA18-05665S, projekt VaV |
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