A  Time Series of BV photometry and H{alpha} Emission Fluxes of the Eclipsing Binary VV Cep

Pollmann, E.; Vollmann, W.; Bennett, P. D.

doi:10.22444/ibvs.6198

Cited by 3 publications

(2 citation statements)

References 1 publication

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Later, additional nine FORS 2 spectropolarimetric observations of ζ Oph were obtained over four consecutive nights. The analysis of the FORS 2 observations showed the presence of a weak magnetic field with a reversal of polarity (Hubrig et al 2013) and an amplitude of about 100 G. The resulting periodogram for the magnetic field measurements using all available lines showed a dominating peak corresponding to a period of about 1.3 day, which is roughly double the period of 0.643 day determined by Pollmann (2012), who studied the variation of the equivalent width of the He I 6678 line. David-Uraz et al (2014) used ESPaDOnS and NARVAL observations of ζ Oph in 2011/12 with much larger uncertainties-typically around 350 G and between 100 and 800 G-and concluded that the upper limit of the dipole field strength is about 224 G and the maximum possible rotation period of 1.1 day.…”

Section: Introductionmentioning

confidence: 76%

THE FIRST SPECTROPOLARIMETRIC MONITORING OF THE PECULIAR O4 Ief SUPERGIANT ζ PUPPIS

Hubrig

Холтыгин

Ilyin

et al. 2016

ApJ

View full text Add to dashboard Cite

The origin of the magnetic field in massive O-type stars is still under debate. To model the physical processes responsible for the generation of O star magnetic fields, it is important to understand whether correlations between the presence of a magnetic field and stellar evolutionary state, rotation velocity, kinematical status, and surface composition can be identified. The O4 Ief supergiant ζ Pup is a fast rotator and a runaway star, which may be a product of a past binary interaction, possibly having had an encounter with the cluster Trumper 10 some 2 Myr ago. The currently available observational material suggests that certain observed phenomena in this star may be related to the presence of a magnetic field. We acquired spectropolarimetric observations of ζ Pup with FORS 2 mounted on the 8 m Antu telescope of the Very Large Telescope to investigate if a magnetic field is indeed present in this star. We show that many spectral lines are highly variable and probably vary with the recently detected period of 1.78 day. No magnetic field is detected in ζ Pup, as no magnetic field measurement has a significance level higher than 2.4σ. Still, we studied the probability of a single sinusoidal explaining the variation of the longitudinal magnetic field measurements.

show abstract

Section: Introductionmentioning

confidence: 76%

THE FIRST SPECTROPOLARIMETRIC MONITORING OF THE PECULIAR O4 Ief SUPERGIANT ζ PUPPIS

Hubrig

Холтыгин

Ilyin

et al. 2016

ApJ

View full text Add to dashboard Cite

show abstract

“…Stothers & Leung 1971), VV Cep, a M2Iab + B0-2V (e.g. Cowley 1969;Pollmann et al 2017) and others where (in most cases) it is possible to see both the characteristic titanium oxide (TiO) bands of a RSG as well as the upper Balmer lines present within a hot un-evolved B-type star. However, searching for binary RSGs blindly and obtaining sufficient signal to noise (S/N) in the fainter bluer wavelengths to hunt for Balmer lines from potential companions is quite a task, particularly as some of these systems are eclipsing binaries where the B star spectrum is not always visible (e.g.…”

Section: Introductionmentioning

confidence: 99%

Binary Red Supergiants: A New Method for Detecting B-type Companions

Neugent

Levesque

Massey

2018

View full text Add to dashboard Cite

With the exception of a few well-known and studied systems, the binary population of red supergiants (RSGs) remains relatively uncharacterized. Famous systems such as VV Cep, 31 Cyg and ζ Aur contain RSG + B star binaries and here we explore whether B stars are the main type of companion we expect from an evolutionary point of view. Using the Geneva evolutionary models we find that this is indeed the case. However, few such systems are known, and we use model spectra to determine how easy such binaries would be to detect observationally. We find that it should be quite difficult to hide a B-type companion given a reasonable signal-to-noise in the optical / blue portion of the spectrum. We next examine spectra of Magellanic Cloud RSGs and newly acquired spectra of Galactic RSGs looking for new systems and refining our conclusions about what types of stars could be hidden in the spectra. Finally, we develop a set of photometric criteria that can help select likely binaries in the future without the overhead of large periodic or spectroscopic surveys.

show abstract

Binary Red Supergiants. II. Discovering and Characterizing B-type Companions

Neugent

Levesque

Massey

et al. 2019

ApJ

View full text Add to dashboard Cite

The percentage of massive main-sequence OB stars in binary systems is thought to be as high as 100%. However, very few Galactic binary red supergiants (RSGs) have been identified, despite the fact that these stars are the evolved descendants of OB stars. As shown in our recent paper, binary RSGs will likely have B-type companions, as dictated by stellar evolution considerations. Such a system will have a very unique photometric signature due to the shape of the spectral energy distribution. Using photometric cutoffs, it should therefore be possible to detect candidate RSG+B star binary systems. Here we present our spectroscopic follow-up observations of such candidates. Out of our initial list of 280 candidates in M31 and M33, we observed 149 and confirmed 63 as newly discovered RSG+B star binary systems. Additional spectra of four candidate systems in the Small Magellanic Cloud confirmed all of them as new RSG+B star binaries including the first known RSG+Be star system. By fitting BSTAR06 and MARCS model atmospheres to the newly obtained spectra, we place estimates on the temperatures and subtypes of both the B stars and RSGs. Overall, we have found 87 new RSG+B star binary systems in M31, M33 and the Small and Large Magellanic Clouds. Our future studies are aimed at determining the binary fraction of RSGs.

show abstract

A Time Series of BV photometry and H{alpha} Emission Fluxes of the Eclipsing Binary VV Cep

Cited by 3 publications

References 1 publication

THE FIRST SPECTROPOLARIMETRIC MONITORING OF THE PECULIAR O4 Ief SUPERGIANT ζ PUPPIS

THE FIRST SPECTROPOLARIMETRIC MONITORING OF THE PECULIAR O4 Ief SUPERGIANT ζ PUPPIS

Binary Red Supergiants: A New Method for Detecting B-type Companions

Binary Red Supergiants. II. Discovering and Characterizing B-type Companions

Contact Info

Product

Resources

About