An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data

Varování

Publikace nespadá pod Filozofickou fakultu, ale pod Přírodovědeckou fakultu. Oficiální stránka publikace je na webu muni.cz.
Autoři

BERNHARD Klaus OTERO Sebastian HUMMERICH Stefan KALTCHEVA Nadia PAUNZEN Ernst BOHLSEN Terry

Rok publikování 2018
Druh Článek v odborném periodiku
Časopis / Zdroj Monthly Notices of the Royal Astronomical Society
Fakulta / Pracoviště MU

Přírodovědecká fakulta

Citace
www http://dx.doi.org/10.1093/mnras/sty1320
Doi http://dx.doi.org/10.1093/mnras/sty1320
Klíčová slova stars: circumstellar matter; Stars: early-type; stars: emission-line Be; stars: oscillations; stars: variables: general
Popis We present an investigation of a large sample of confirmed (N = 233) and candidate (N = 54) Galactic classical Be stars (mean V magnitude range of 6.4-12.6 mag), with the main aim of characterizing their photometric variability. Our sample stars were preselected among early-type variables using light-curve morphology criteria. Spectroscopic information was gleaned from the literature, and archival and newly acquired spectra. Photometric variability was analysed using archival ASAS-3 time-series data. To enable a comparison of results, we have largely adopted the methodology of Labadie-Bartz et al. (2017), who carried out a similar investigation based on KELT data. Complex photometric variations were established in most stars: outbursts on different time-scales (in 73 +/- 5 per cent of stars), long-term variations (36 +/- 6 per cent), periodic variations on intermediate time-scales (1 +/- 1 per cent), and short-term periodic variations (6 +/- 3 per cent). 24 +/- 6 per cent of the outbursting stars exhibit (semi) periodic outbursts. We close the apparent void of rare outbursters reported by Labadie-Bartz et al. (2017) and show that Be stars with infrequent outbursts are not rare. While we do not find a significant difference in the percentage of stars showing outbursts among early-type, mid-type, and late-type Be stars, we show that early-type Be stars exhibit much more frequent outbursts. We have measured rising and falling times for well-covered and well-defined outbursts. Nearly all outburst events are characterized by falling times that exceed the rising times. No differences were found between early-, mid-, and late-type stars; a single non-linear function adequately describes the ratio of falling time to rising time across all spectral subtypes, with the ratio being larger for short events.
Související projekty:

Používáte starou verzi internetového prohlížeče. Doporučujeme aktualizovat Váš prohlížeč na nejnovější verzi.