J 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 BAKOWSKA

Základní 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

Štítky

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.