X-ray and optical periodicities in X-ray binaries I. A0535+26

Larionov, V. M.; Lyuty, V. M.; Зайцева, Г. С.

doi:10.1051/0004-6361:20011276

Cited by 13 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although differential photometry using nearby stars has been performed on some of the targets before (Mendelson & Mazeh 1991;Bell et al 1993;Finley et al 1994;Goranskii 2001;Larionov et al 2001;Baykal et al 2005;Kızıloǧlu et al 2007Kızıloǧlu et al , 2009Sarty et al 2009), this is the first systematic attempt to define secondary standard stars within a few arcminutes of the targets that are suitable for variability studies in a large sample of sources. The use of comparison stars, i.e.…”

Section: Data Analysis and Selection Criteria For Secondary Standardsmentioning

confidence: 99%

Long-term variability of high-mass X-ray binaries

Reig

Fabregat

2015

A&A

View full text Add to dashboard Cite

We present photometric observations of the field around the optical counterparts of high-mass X-ray binaries. Our aim is to study the long-term photometric variability in correlation with their X-ray activity and derive a set of secondary standard stars that can be used for time series analysis. We find that the donors in Be/X-ray binaries exhibit larger amplitude changes in the magnitudes and colours than those hosting a supergiant companion. The amplitude of variability increases with wavelength in Be/X-ray binaries and remains fairly constant in supergiant systems. When time scales of years are considered, a good correlation between the X-ray and optical variability is observed. The X-rays cease when optical brightness decreases. These results reflect the fact that the circumstellar disk in Be/X-ray binaries is the main source of both optical and X-ray variability. We also derive the colour excess, E(B − V), selecting data at times when the contribution of the circumstellar disk was supposed to be at minimum, and we revisit the distance estimates.

show abstract

Section: Data Analysis and Selection Criteria For Secondary Standardsmentioning

confidence: 99%

Long-term variability of high-mass X-ray binaries

Reig

Fabregat

2015

A&A

View full text Add to dashboard Cite

show abstract

“…They suggest that the missing outburst phenomenon can be attributed to a property of the spherically symmetrical accretion onto the interchange-stable magnetosphere of the neutron star. Larionov et al (2001), analyzing a large set of optical photometric data, found a modulation period of 103 days, which they attribute to the beating between the orbital period of the system and a precession period of ≈1400 days, which can be assigned either to an accretion disc around the neutron star, or a warped excretion disc around the Be star. Romero et al (2001) have suggested the possibility that HDE 245770/A0535+26 system may be identified with the otherwise unidentified variable EGRET gamma ray source 3EG J0542+2610, assuming the existence of a temporary accretion disc around the neutron star, i.e.…”

Section: Values)mentioning

confidence: 99%

HeI doubled emission lines from A0535+26 ≡ HDE 245770

Giovannelli

Bernabei

Rossi

et al. 2007

A&A

View full text Add to dashboard Cite

We report results of the spectroscopy for V725 Tau (HDE 245770, BD +26• 883), commonly known as Flavia's star, which is the optical counterpart of the X-ray pulsar A0535+26, carried out at the 1.5 m Loiano telescope during one run of observations of this star spread over a period of years. The HeI emission lines clearly show doubling, which is good evidence for the presence of a disc. In this paper we critically discuss the possibility that this disc is a temporary accretion disc around the neutron star, a view that contrasts to the usual interpretation, which considers that this sort of doubling in the HeI emission lines is due to a disc formed by gas expelled from the Be star. In the former case the outer radius of the accretion disc could range from 5.9 × 10 10 cm to 2.1 × 10 11 cm, taking the most probable range into account for the orbital inclination of the binary system, from 35• to 39• . The presence of such a temporary accretion disc around the neutron star was predicted by Giovannelli & Ziółkowski (1990).

show abstract

“…Disc-less phases have been seen in a number of Be/X-ray binaries but only two have been observed frequently enough as to allow a meaningful comparison with 4U 0115+63, namely, A 0535+26 (Lyuty & Zaitseva 2000;Larionov et al 2001;Clark et al 1999;Haigh et al 2004) and X Per (Clark et al 2001, and references therein). The three systems show extended low states, although its duration differs: ∼600 days (MJD 50 700-51 300) for A 0535+26 (Haigh et al 2004;Zaitseva 2005), ∼800 days (MJD 52 000-52 800) for 4U 0115+63 (Fig.…”

Section: The Low Statementioning

confidence: 99%

The Be/X-ray transient 4U 0115+63/V635 Cassiopeiae

Reig¹,

Larionov²,

Negueruela³

et al. 2006

A&A

Self Cite

View full text Add to dashboard Cite

Context. 4U 0115+63 is one of the most active and best studied Be/X-ray transients. Previous studies of 4U 0115+63 have led to the suggestion that 4U 0115+63 undergoes relatively fast quasi-cyclic activity. However, due to the lack of good coverage of the observations, the variability time scales are uncertain. Aims. Our objective is to investigate the long-term behaviour of 4U 0115+63/V635 Cas to confirm its quasi-cyclic nature and to explain its correlated optical/IR and X-ray variability. Methods. We have performed optical/IR photometric observations and optical spectroscopic observations of 4U 0115+63/V635 Cas over the last decade with unprecedented coverage. We have focused on the Hα line variability and the long-term changes of the photometric magnitudes and colours and investigated these changes in correlation with the X-ray activity of the source. Results. The optical and infrared emission is characterised by cyclic changes with a period of ∼5 years. This long-term variability is attributed to the state of the circumstellar disc around the Be star companion. Each cycle involves a low state when the disc is very weak or absent and the associated low amplitude variability is orbitally modulated and a high state when a perturbed disc precesses, giving rise to fast and large amplitude photometric changes. X-ray outbursts in 4U 0115+63 come in pairs, i.e., two in every cycle. However, sometimes the second outburst is missing. Conclusions. Our results can be explained within the framework of the decretion disc model. The neutron star acts as the perturbing body, truncating and distorting the disc. The first outburst would occur before the disc is strongly perturbed. The second outburst leads to the dispersal of the disc and marks the end of the perturbed phase.

show abstract

X-ray and optical periodicities in X-ray binaries I. A0535+26

Cited by 13 publications

References 17 publications

Long-term variability of high-mass X-ray binaries

Long-term variability of high-mass X-ray binaries

HeI doubled emission lines from A0535+26 ≡ HDE 245770

The Be/X-ray transient 4U 0115+63/V635 Cassiopeiae

Contact Info

Product

Resources

About