2016
Peculiar double-periodic pulsation in RR Lyrae stars of the OGLE collection - I. Long-period stars with dominant radial fundamental mode
SMOLEC, Radoslaw, Zdeněk PRUDIL, Marek SKARKA a Karolina BAKOWSKAZákladní údaje
Originální název
Peculiar double-periodic pulsation in RR Lyrae stars of the OGLE collection - I. Long-period stars with dominant radial fundamental mode
Autoři
SMOLEC, Radoslaw (616 Polsko, garant), Zdeněk PRUDIL (203 Česká republika, domácí), Marek SKARKA (203 Česká republika) a Karolina BAKOWSKA (616 Polsko)
Vydání
Monthly Notices of the Royal Astronomical Society, Priestley and Weale, 2016, 0035-8711
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10308 Astronomy
Stát vydavatele
Velká Británie a Severní Irsko
Utajení
není předmětem státního či obchodního tajemství
Odkazy
Impakt faktor
Impact factor: 4.961
Kód RIV
RIV/00216224:14310/16:00092993
Organizační jednotka
Přírodovědecká fakulta
UT WoS
000383481100048
Klíčová slova anglicky
methods: data analysis; stars: horizontal branch; stars: oscillations; stars: variables: RR Lyrae
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 24. 2. 2020 15:34, Mgr. Marie Šípková, DiS.
Anotace
V originále
We present the discovery of a new, peculiar form of double-periodic pulsation in RR Lyrae stars. In four, long-period (P > 0.6 d) stars observed by the Optical Gravitational Lensing Experiment, and classified as fundamental mode pulsators (RRab), we detect additional, low-amplitude variability, with period shorter than fundamental mode period. The period ratios fall in a range similar to double-mode fundamental and first overtone RR Lyrae stars (RRd), with the exception of one star, in which the period ratio is significantly lower and nearly exactly equals 0.7. Although period ratios are fairly different for the four stars, the light-curve shapes corresponding to the dominant, fundamental mode are very similar. The peak-to-peak amplitudes and amplitude ratios (Fourier parameters R-21 and R-31) are among the highest observed in RRab stars of similar period, while Fourier phases (phi(21) and phi(31)) are among the lowest observed in RRab stars. If the additional variability is interpreted as due to radial first overtone, then, the four stars are the most extreme RRd variables of the longest pulsation periods known. Indeed, the observed period ratios can be well modelled with high-metallicity pulsation models. However, at such long pulsation periods, first overtone is typically damped. Five other candidates, with weak signature of additional variability, sharing the same characteristics, were also detected and are briefly discussed.