The field high-amplitude SX Phe variable BL Cam: results from a multisite photometric campaign

Fauvaud, S.; Sareyan, J. P.; Ribas, I.; Rodríguez‐López, C.; Lampens, P.; Klingenberg, G.; Farrell, Jeremiah; Fumagalli, Francesca; Simonetti, J. H.; Wolf, M.; Santacana, G.; Zhou, A. Y.; Michel, R.; Fox-Machado, L.; Álvarez, M.; Nava-Vega, Adriana; López-González, M. J.; Casanova, V.; Aceituno, F. J.; Scheggia, I.; Rives, J.-J.; Hintz, E. G.; Cauteren, P. van; Helvacı, M.; Yeşilyaprak, Cahit; Graham, Keith; Král, L.; Kocián, R.; Kučáková, H.; Fauvaud, M.; Granslo, B. H.; Michelet, J.; Nicholson, M.; Vugnon, J.-M.; Kotková, L.; Truparová, K.; Ulusoy, C.; Yaşarsoy, B.; Avdibegović, A.; Blaĭek, M.; Kliner, J.; Zasche, P.; Bartošíková, S.; Vilášek, M.; Trondal, O.; Abbeel, F. Van Den; Behrend, R.; Wücher, H.

doi:10.1051/0004-6361/201014243

Cited by 12 publications

(8 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(H14) (H14) (this paper) (1) (2) (3) (4) (5) star, and was found to be in a 144.2 d close binary system, possibly orbited by a brown dwarf having an orbital period ∼9.3 years (Fauvaud et al 2006(Fauvaud et al , 2010;…”

Section: Other Sx Phe Binariesmentioning

confidence: 92%

Metal-rich SX Phe stars in theKeplerfield

Nemec

Balona

Murphy

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

A spectroscopic and photometric analysis has been carried out for thirty-two candidate SX Phe variable blue straggler stars in the Kepler-field (Balona & Nemec 2012). Radial velocities (RVs), space motions (U, V, W ), projected rotation velocities (v sin i), spectral types, and atmospheric characteristics (T eff , log g, [Fe/H], ξ t , ζ RT , etc.) are presented for 30 of the 32 stars. Although several stars are metal-weak with extreme halo orbits, the mean [Fe/H] of the sample is near solar, thus the stars are more metalrich than expected for a typical sample of Pop. II stars, and more like halo metal-rich A-type stars (Perry 1969). Two thirds of the stars are fast rotators with v sin i > 50 km/s, including four stars with v sin i > 200 km/s. Three of the stars have (negative) RVs > 250 km/s, five have retrograde space motions, and 21 have total speeds (relative to the LSR) > 400 km/s. All but one of the 30 stars have positions in a Toomre diagram consistent with the kinematics of bona fide halo stars (the exception being a thick-disk star). Observed Rømer time delays, pulsation frequency modulations and light curves suggest that at least one third of the stars are in binary (or triple) systems with orbital periods ranging from 2.3 days to more than four years.

show abstract

Section: Other Sx Phe Binariesmentioning

confidence: 92%

Metal-rich SX Phe stars in theKeplerfield

Nemec

Balona

Murphy

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…The change rate of the main period of BL Cam was determined by previous authors using a parabolic fit (Hintz et al 1997;Zhou et al 1999;Fauvaud et al 2006;Fu et al 2008;Fauvaud et al 2010;Conidis & Delaney 2013). The change rate of the main period determined in this work is (1/P)(dP/dt) = -2.39 (8)×10 −8 yr −1 .…”

Section: Period Changesmentioning

confidence: 99%

“…Fourier power spectra of the frequency pre-whitening process for the light curves of BL Cam in V band in 2014.van Cauteren & Wils 2000;Zhou et al 2001;Wolf et al 2002;Kim et al 2003;Fauvaud et al 2006;Fu et al 2008;Fauvaud et al 2010;Conidis & Delaney 2013), we tried to reanalyze the O−C diagram of BL Cam.…”

mentioning

confidence: 99%

Pulsations of the SX Phe Star BL Camelopardalis

Zong

Esamdin

et al. 2019

PASP

View full text Add to dashboard Cite

We carried out photometric observations of the SX Phe star BL Cam in 2014, 2017 and 2018 using Nanshan 1-m telescope. In addition to the dominated frequency of 25.5790(3) cd −1 and its two harmonics, an independent frequency of 25.247 (2) cd −1 , which is a nonradial mode frequency, was detected from the data in 2014. A total of 123 new times of light maxima were determined from our light curves in the three years, which, together with that published in the literature, were used to analyze the O−C diagram. The change rate of the main period was derived as (1/P)(dP/dt) = -2.39 (8)×10 −8 yr −1 , which is lower than that published in previous literature. A periodical change with a period of 14.01 (9) yr was found in the residuals of the O−C curve fitting. If it was caused by the light-time effect, BL Cam should be a binary system. The mass of the companion was restricted as low as that of a brown dwarf. No evidence of the triple system suggested by previous authors was shown in our analysis.

show abstract

“…The SX Phe variables are A–F type pulsating stars with frequencies in the range of 5–40 d −1 (Nemec et al ; Jeon et al ). There are 14 SX Phe stars in the general field which have characteristics similar to the high‐amplitude δ Scuti stars except that they have high proper motions and low metallicity (Fauvaud et al ). In our Galaxy, low metallicity usually indicates a different population type and hence a different evolutionary state than normal metallicity.…”

Section: Introductionmentioning

confidence: 99%

A search for SX Phe stars amongKeplerδ Scuti stars

Balona

Nemec

2012

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The SX Phe stars are Population II pulsating variables lying below the horizontal branch. Their pulsation characteristics resemble those of δ Sct stars. Since old stars in the Kepler field situated in the thick disc or halo are likely to have kinematics different from δ Sct stars, we use proper motions and tangential velocities to search for possible SX Phe variables among 1424 Kepler δ Scuti stars. Tangential velocities derived from distances obtained from the photometric calibration in the Kepler input catalogue appear to be an effective method of separation between thin‐disc and thick‐disc/halo stellar populations. Using this method, 34 candidate SX Phe stars are identified, eight of which are located more than 0.5 kpc above the galactic plane. We find that the light curves of these stars cannot be distinguished from those of normal δ Scuti stars. It is generally thought that field SX Phe stars have high amplitudes and only one or two frequencies, but such light curves are rare among the candidate SX Phe stars in the Kepler field. We suggest that the relatively high amplitudes, which until now have been a defining characteristic of field SX Phe stars, are merely a selection effect. This supports the recent finding of several low‐amplitude multiperiodic SX Phe stars in some globular clusters.

show abstract

The field high-amplitude SX Phe variable BL Cam: results from a multisite photometric campaign

Cited by 12 publications

References 41 publications

Metal-rich SX Phe stars in theKeplerfield

Metal-rich SX Phe stars in theKeplerfield

Pulsations of the SX Phe Star BL Camelopardalis

A search for SX Phe stars amongKeplerδ Scuti stars

Contact Info

Product

Resources

About