Time-dependent spectral-feature variations of stars displaying
the B[e] phenomenon

J 2013

Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon

KUČEROVÁ, Blanka; D. KORCAKOVA; Jan POLSTER; M. WOLF; V. VOTRUBA et al.

Základní údaje

Originální název

Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon

Autoři

KUČEROVÁ, Blanka; D. KORCAKOVA; Jan POLSTER; M. WOLF; V. VOTRUBA; J. KUBAT; P. SKODA; M. SLECHTA a M. KRIZEK

Vydání

ASTRONOMY & ASTROPHYSICS, LES ULIS CEDEX A, EDP SCIENCES S A, 2013, 0004-6361

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

Impakt faktor

Impact factor: 4.479

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/13:00107092

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

stars: individual: MWC 342; stars: emission-line Be; stars: mass-loss; binaries: spectroscopic; circumstellar matter

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 10. 12. 2019 12:27, Mgr. Marie Novosadová Šípková, DiS.

Anotace

V originále

The B[e] phenomenon can be present in stars of different types and at different evolutionary stages. Very extended circumstellar matter prohibits the study of the atmosphere of these stars, since no photospheric lines are usually observed. Standard stellar atmosphere models are thus not applicable when determining stellar parameters. One of a few possibilities for comprehending the nature of these objects is to study their time variations. Unfortunately, almost no set of spectra with an adequate time description is available for these objects. We obtained an extensive set of MWC 342 spectra (102) during the years 2004-2010 in the wavelength interval around the Ha line (6265-6765 angstrom) to focus on the time variability of the spectral lines in this region. We chose MWC 342 from the known stars showing the B[e] phenomenon since, although this star is very bright, its evolutionary status and the role of binarity in the appearance of the B[e] phenomenon are unknown. The time dependence of radial velocities and equivalent widths of emission lines was measured for the Ha line, He I 6678 angstrom, [OI] 6300, 6364 angstrom, Fe II 6318, 6384, 6344 and 6456 angstrom, and Si II 6347, 6371 angstrom. We detected variability in the spectral lines on both short and long time scales. He I 6678 angstrom shows day-to-day changes in its line profile. We observed pure absorption, pure emission, the P Cygni profile, and the inverse P Cygni profile in this line. There are time intervals where this line disappeared. The Ha line also shows considerable changes in its line profile, radial velocities, and equivalent widths. A cycle of about 1560 days was detected in its radial velocities. The detailed description of the variations in MWC 342 spectra reveals its important properties. The inner atmosphere is affected by changes of days, while existing long-term waves are propagated into the outer regions. It is highly probable that the continuum radiation in the visual region is also variable. The inverse P Cygni profile was probably observed when the continuum radiation reached its maximum. These properties indicate the complicated nature of this object. We discuss here a possible explanation of the observations by a stellar wind supported by pulsations.

Citovat

KUČEROVÁ, Blanka; D. KORCAKOVA; Jan POLSTER; M. WOLF; V. VOTRUBA; J. KUBAT; P. SKODA; M. SLECHTA a M. KRIZEK. Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon. ASTRONOMY & ASTROPHYSICS. LES ULIS CEDEX A: EDP SCIENCES S A, 2013, roč. 554, A143, s. 1-26. ISSN 0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/201117437.

@article{1589859,
   author = {Kučerová, Blanka and Korcakova, D. and Polster, Jan and Wolf, M. and Votruba, V. and Kubat, J. and Skoda, P. and Slechta, M. and Krizek, M.},
   article_location = {LES ULIS CEDEX A},
   article_number = {A143},
   doi = {https://doi.org/10.1051/0004-6361/201117437},
   keywords = {stars: individual: MWC 342; stars: emission-line Be; stars: mass-loss; binaries: spectroscopic; circumstellar matter},
   language = {eng},
   issn = {0004-6361},
   journal = {ASTRONOMY & ASTROPHYSICS},
   title = {Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon},
   url = {https://www.aanda.org/articles/aa/pdf/2013/06/aa17437-11.pdf},
   volume = {554},
   year = {2013}
}

TY  - JOUR
ID  - 1589859
AU  - Kučerová, Blanka - Korcakova, D. - Polster, Jan - Wolf, M. - Votruba, V. - Kubat, J. - Skoda, P. - Slechta, M. - Krizek, M.
PY  - 2013
TI  - Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon
JF  - ASTRONOMY & ASTROPHYSICS
VL  - 554
IS  - A143
SP  - 1-26
EP  - 1-26
PB  - EDP SCIENCES S A
SN  - 00046361
KW  - stars: individual: MWC 342
KW  - stars: emission-line Be
KW  - stars: mass-loss
KW  - binaries: spectroscopic
KW  - circumstellar matter
UR  - https://www.aanda.org/articles/aa/pdf/2013/06/aa17437-11.pdf
L2  - https://www.aanda.org/articles/aa/pdf/2013/06/aa17437-11.pdf
N2  - The B[e] phenomenon can be present in stars of different types and at different evolutionary stages. Very extended circumstellar matter prohibits the study of the atmosphere of these stars, since no photospheric lines are usually observed. Standard stellar atmosphere models are thus not applicable when determining stellar parameters. One of a few possibilities for comprehending the nature of these objects is to study their time variations. Unfortunately, almost no set of spectra with an adequate time description is available for these objects. We obtained an extensive set of MWC 342 spectra (102) during the years 2004-2010 in the wavelength interval around the Ha line (6265-6765 angstrom) to focus on the time variability of the spectral lines in this region. We chose MWC 342 from the known stars showing the B[e] phenomenon since, although this star is very bright, its evolutionary status and the role of binarity in the appearance of the B[e] phenomenon are unknown. The time dependence of radial velocities and equivalent widths of emission lines was measured for the Ha line, He I 6678 angstrom, [OI] 6300, 6364 angstrom, Fe II 6318, 6384, 6344 and 6456 angstrom, and Si II 6347, 6371 angstrom. We detected variability in the spectral lines on both short and long time scales. He I 6678 angstrom shows day-to-day changes in its line profile. We observed pure absorption, pure emission, the P Cygni profile, and the inverse P Cygni profile in this line. There are time intervals where this line disappeared. The Ha line also shows considerable changes in its line profile, radial velocities, and equivalent widths. A cycle of about 1560 days was detected in its radial velocities. The detailed description of the variations in MWC 342 spectra reveals its important properties. The inner atmosphere is affected by changes of days, while existing long-term waves are propagated into the outer regions. It is highly probable that the continuum radiation in the visual region is also variable. The inverse P Cygni profile was probably observed when the continuum radiation reached its maximum. These properties indicate the complicated nature of this object. We discuss here a possible explanation of the observations by a stellar wind supported by pulsations.
ER  -

KUČEROVÁ, Blanka; D. KORCAKOVA; Jan POLSTER; M. WOLF; V. VOTRUBA; J. KUBAT; P. SKODA; M. SLECHTA a M. KRIZEK. Time-dependent spectral-feature variations of stars displaying the B[e] phenomenon. \textit{ASTRONOMY \&{} ASTROPHYSICS}. LES ULIS CEDEX A: EDP SCIENCES S A, 2013, roč.~554, A143, s.~1-26. ISSN~0004-6361. Dostupné z: https://doi.org/10.1051/0004-6361/201117437.

Přehled o publikaci