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

J 2018

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

BERNHARD, Klaus; Sebastian OTERO; Stefan HUMMERICH; Nadia KALTCHEVA; Ernst PAUNZEN et. al.

Basic information

Original name

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

Authors

BERNHARD, Klaus (40 Austria); Sebastian OTERO (32 Argentina); Stefan HUMMERICH (276 Germany); Nadia KALTCHEVA (840 United States of America); Ernst PAUNZEN (40 Austria, guarantor, belonging to the institution) and Terry BOHLSEN (36 Australia)

Edition

Monthly Notices of the Royal Astronomical Society, MALDEN, WILEY, 2018, 0035-8711

Other information

Language

English

Type of outcome

Article in a journal

Field of Study

10308 Astronomy

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

is not subject to a state or trade secret

References:

URL

Impact factor

Impact factor: 5.231

RIV identification code

RIV/00216224:14310/18:00104476

Organization unit

Faculty of Science

DOI

https://doi.org/10.1093/mnras/sty1320

UT WoS

000441382300005

EID Scopus

2-s2.0-85051533134

Keywords in English

stars: circumstellar matter; Stars: early-type; stars: emission-line Be; stars: oscillations; stars: variables: general

Abstract

In the original language

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.

Links

7AMB17AT030, research and development project

Name: Analýza hvězd se skvrnami pomocí kvalitních pozorovacích dat

Investor: Ministry of Education, Youth and Sports of the CR

Cite

BERNHARD, Klaus; Sebastian OTERO; Stefan HUMMERICH; Nadia KALTCHEVA; Ernst PAUNZEN and Terry BOHLSEN. An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data. Monthly Notices of the Royal Astronomical Society. MALDEN: WILEY, 2018, vol. 479, No 3, p. 2909-2967. ISSN 0035-8711. Available from: https://doi.org/10.1093/mnras/sty1320.

@article{1468438,
   author = {Bernhard, Klaus and Otero, Sebastian and Hummerich, Stefan and Kaltcheva, Nadia and Paunzen, Ernst and Bohlsen, Terry},
   article_location = {MALDEN},
   article_number = {3},
   doi = {https://doi.org/10.1093/mnras/sty1320},
   keywords = {stars: circumstellar matter; Stars: early-type; stars: emission-line Be; stars: oscillations; stars: variables: general},
   language = {eng},
   issn = {0035-8711},
   journal = {Monthly Notices of the Royal Astronomical Society},
   title = {An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data},
   url = {http://dx.doi.org/10.1093/mnras/sty1320},
   volume = {479},
   year = {2018}
}

TY  - JOUR
ID  - 1468438
AU  - Bernhard, Klaus - Otero, Sebastian - Hummerich, Stefan - Kaltcheva, Nadia - Paunzen, Ernst - Bohlsen, Terry
PY  - 2018
TI  - An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data
JF  - Monthly Notices of the Royal Astronomical Society
VL  - 479
IS  - 3
SP  - 2909-2967
EP  - 2909-2967
PB  - WILEY
SN  - 00358711
KW  - stars: circumstellar matter
KW  - Stars: early-type
KW  - stars: emission-line Be
KW  - stars: oscillations
KW  - stars: variables: general
UR  - http://dx.doi.org/10.1093/mnras/sty1320
N2  - 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.
ER  -

BERNHARD, Klaus; Sebastian OTERO; Stefan HUMMERICH; Nadia KALTCHEVA; Ernst PAUNZEN and Terry BOHLSEN. An investigation of the photometric variability of confirmed and candidate Galactic Be stars using ASAS-3 data. \textit{Monthly Notices of the Royal Astronomical Society}. MALDEN: WILEY, 2018, vol.~479, No~3, p.~2909-2967. ISSN~0035-8711. Available from: https://doi.org/10.1093/mnras/sty1320.

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