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

J 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; Zdeněk MIKULÁŠEK; G.W. HENRY; Jan JANÍK ; Oleg KOCHUKHOV; Andrzej PIGULSKI; P. LETO; Corado TRIGILIO; Iva KRTIČKOVÁ; Theresa LUFTINGER; Milan PRVÁK a Adam TICHÝ

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

Full Text

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/19:00107424

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

stars: chemically peculiar; stars: early-type; stars: variables: general; stars: individual: CU Vir

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 29. 3. 2021 14:17, Mgr. Marie Novosadová 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

Název: Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

Investor: Grantová agentura ČR, Atmosféry a okolohvězdné prostředí magnetických horkých hvězd

GA18-05665S, projekt VaV

Název: Ztráta hmoty v pozdních fázích vývoje hmotných hvězd

Investor: Grantová agentura ČR, Ztráta hmoty v pozdních fázích vývoje hmotných hvězd

Citovat

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; G.W. HENRY; Jan JANÍK; Oleg KOCHUKHOV; Andrzej PIGULSKI; P. LETO; Corado TRIGILIO; Iva KRTIČKOVÁ; Theresa LUFTINGER; Milan PRVÁK a Adam TICHÝ. HST/STIS analysis of the first main sequence pulsar CU Virginis. ASTRONOMY & ASTROPHYSICS. LES ULIS CEDEX A: EDP SCIENCES S A, 2019, roč. 625, MAY 7 2019, s. 1-12. ISSN 1432-0746. Dostupné z: https://doi.org/10.1051/0004-6361/201834937.

@article{1534858,
   author = {Krtička, Jiří and Mikulášek, Zdeněk and Henry, G.W. and Janík, Jan and Kochukhov, Oleg and Pigulski, Andrzej and Leto, P. and Trigilio, Corado and Krtičková, Iva and Luftinger, Theresa and Prvák, Milan and Tichý, Adam},
   article_location = {LES ULIS CEDEX A},
   article_number = {MAY 7 2019},
   doi = {https://doi.org/10.1051/0004-6361/201834937},
   keywords = {stars: chemically peculiar; stars: early-type; stars: variables: general; stars: individual: CU Vir},
   language = {eng},
   issn = {1432-0746},
   journal = {ASTRONOMY & ASTROPHYSICS},
   title = {HST/STIS analysis of the first main sequence pulsar CU Virginis},
   url = {https://www.aanda.org/articles/aa/abs/2019/05/aa34937-18/aa34937-18.html},
   volume = {625},
   year = {2019}
}

TY  - JOUR
ID  - 1534858
AU  - Krtička, Jiří - Mikulášek, Zdeněk - Henry, G.W. - Janík, Jan - Kochukhov, Oleg - Pigulski, Andrzej - Leto, P. - Trigilio, Corado - Krtičková, Iva - Luftinger, Theresa - Prvák, Milan - Tichý, Adam
PY  - 2019
TI  - HST/STIS analysis of the first main sequence pulsar CU Virginis
JF  - ASTRONOMY & ASTROPHYSICS
VL  - 625
IS  - MAY 7 2019
SP  - 1-12
EP  - 1-12
PB  - EDP SCIENCES S A
SN  - 14320746
KW  - stars: chemically peculiar
KW  - stars: early-type
KW  - stars: variables: general
KW  - stars: individual: CU Vir
UR  - https://www.aanda.org/articles/aa/abs/2019/05/aa34937-18/aa34937-18.html
L2  - https://www.aanda.org/articles/aa/abs/2019/05/aa34937-18/aa34937-18.html
N2  - 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.
ER  -

KRTIČKA, Jiří; Zdeněk MIKULÁŠEK; G.W. HENRY; Jan JANÍK; Oleg KOCHUKHOV; Andrzej PIGULSKI; P. LETO; Corado TRIGILIO; Iva KRTIČKOVÁ; Theresa LUFTINGER; Milan PRVÁK a Adam TICHÝ. HST/STIS analysis of the first main sequence pulsar CU Virginis. \textit{ASTRONOMY \&{}amp; ASTROPHYSICS}. LES ULIS CEDEX A: EDP SCIENCES S A, 2019, roč.~625, MAY 7 2019, s.~1-12. ISSN~1432-0746. Dostupné z: https://doi.org/10.1051/0004-6361/201834937.

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