Orbital solutions for SB2 systems with a HgMn component

Catanzaro, G.; Leto, P.

doi:10.1051/0004-6361:20034445

Cited by 21 publications

(23 citation statements)

References 28 publications

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“…Along with the intrinsic spectra of the components it provided their radial velocities. The fit of our RV measurements together with RVs from previous studies (Young 1976;Yushchenko et al 1999Yushchenko et al , 2001Catanzaro & Leto 2004) with the theoretical model enabled us to improve the orbital elements of 66 Eri.…”

Section: Summary and Discussionmentioning

confidence: 70%

“…The new orbital elements are listed in Table 3, while Fig. 4 compares the respective predicted RV curves with Catanzaro & Leto (2004), we significantly improved the accuracy of the orbital period and of the velocity amplitudes, obtaining a mass ratio with a precision better than 1%.…”

Section: Spectral Disentanglingmentioning

confidence: 96%

“…These data, presented in Table 2, have typical error bars of 0.1-0.2 km s −1 . We combined our RVs with the velocities published by Young (1976), Yushchenko et al (1999Yushchenko et al ( , 2001, and Catanzaro & Leto (2004), deriving improved orbital parameters of the system. The new orbital elements are listed in Table 3, while Fig.…”

Section: Spectral Disentanglingmentioning

confidence: 99%

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Chemical spots in the absence of magnetic field in the binary HgMn star 66 Eridani

Makaganiuk

Kochukhov

Piskunov

et al. 2011

A&A

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Context. According to our current understanding, a subclass of the upper main-sequence chemically peculiar stars, called mercurymanganese (HgMn), is non-magnetic. Nevertheless, chemical inhomogeneities were recently discovered on their surfaces. At the same time, no global magnetic fields stronger than 1-100 G are detected by systematic studies. Aims. The goals of our study are to search for a magnetic field in the HgMn binary system 66 Eri and to investigate chemical spots on the stellar surfaces of both components. Methods. Our analysis is based on high-quality spectropolarimetric time-series observations obtained during 10 consecutive nights with the HARPSpol instrument at the ESO 3.6-m telescope. To increase the sensitivity of the magnetic field search we employed a least-squares deconvolution (LSD). We used spectral disentangling to measure radial velocities and study the line profile variability. Chemical spot geometry was reconstructed using multi-line Doppler imaging. Results. We report a non-detection of magnetic field in 66 Eri, with error bars 10-24 G for the longitudinal field. Circular polarization profiles also do not indicate any signatures of complex surface magnetic fields. For a simple dipolar field configuration we estimated an upper limit of the polar field strength to be 60-70 G. For the HgMn component we found variability in spectral lines of Ti, Ba, Y, and Sr with the rotational period equal to the orbital one. The surface maps of these elements reconstructed with the Doppler imaging technique show a relative underabundance on the hemisphere facing the secondary component. The contrast of chemical inhomogeneities ranges from 0.4 for Ti to 0.8 for Ba.

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Section: Summary and Discussionmentioning

confidence: 70%

Section: Spectral Disentanglingmentioning

confidence: 96%

Section: Spectral Disentanglingmentioning

confidence: 99%

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Chemical spots in the absence of magnetic field in the binary HgMn star 66 Eridani

Makaganiuk

Kochukhov

Piskunov

et al. 2011

A&A

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“…HD 32964 (=66 Eri) is a CP star of HgMn type (Renson 1991), and a spectroscopic binary (Frost & Struve 1924) composed of two nearly equal mass stars of M sin 3 i ∼ 2.4 M in a 5.2-day orbit (Yushchenko et al 2001;Catanzaro & Leto 2004).…”

Section: Appendix A: Individual Targetsmentioning

confidence: 99%

Testing the companion hypothesis for the origin of the X-ray emission from intermediate-mass main-sequence stars

Stelzer¹,

Huélamo

Micela³

et al. 2006

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Context. The X-ray emission from B-type main-sequence stars is a longstanding mystery in stellar coronal research. Since there is no theory at hand that explains intrinsic X-ray emission from intermediate-mass main-sequence stars, the observations have often been interpreted in terms of (unknown) late-type magnetically active companion stars. Aims. Resolving the hypothesized companions requires high spatial resolution observations in the infrared and in X-rays. We use Chandra imaging observations to spatially resolve a sample of main-sequence B-type stars with recently discovered companions at arcsecond separation. Methods. Our strategy is to search for X-ray emission at the position of both the B-type primary and the faint companion. Results. We find that all spatially resolved companions are X-ray emitters, but seven out of eleven intermediate-mass stars are also X-ray sources. If this emission is interpreted in terms of additional sub-arcsecond or spectroscopic companions, this implies a high multiplicity of B-type stars. Firm results on B star multiplicity pending, the alternative, that B stars produce intrinsic X-rays, cannot be discarded. An appropriate scenario would be a magnetically confined wind, as suggested for the X-ray emission of the magnetic Ap star IQ Aur. However, the only Ap star in the Chandra sample is not detected in X-rays, and therefore does not support this picture.

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“…These late, main-sequence B stars have effective temperatures ranging from 10 500 to 15 000 K and masses roughly between 2.5 and 5 M (e.g., Adelman et al 2003). They are also often found in binary systems (e.g., Catanzaro & Leto 2004;Schöller et al 2010Schöller et al , 2012.…”

Section: Introductionmentioning

confidence: 99%

A search for pulsations in the HgMn star HD 45975 with CoRoT photometry and ground-based spectroscopy

Morel

Briquet

Auvergne

et al. 2013

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The existence of pulsations in HgMn stars is still being debated. To provide the first unambiguous observational detection of pulsations in this class of chemically peculiar objects, the bright star HD 45975 was monitored for nearly two months by the CoRoT satellite. Independent analyses of the light curve provide evidence of monoperiodic variations with a frequency of 0.7572 d −1 and a peak-topeak amplitude of ∼2800 ppm. Multisite, ground-based spectroscopic observations overlapping the CoRoT observations show the star to be a long-period, single-lined binary. Furthermore, with the notable exception of mercury, they reveal the same periodicity as in photometry in the line moments of chemical species exhibiting strong overabundances (e.g., Mn and Y). In contrast, lines of other elements do not show significant variations. As found in other HgMn stars, the pattern of variability consists in an absorption bump moving redwards across the line profiles. We argue that the photometric and spectroscopic changes are more consistent with an interpretation in terms of rotational modulation of spots at the stellar surface. In this framework, the existence of pulsations producing photometric variations above the ∼50 ppm level is unlikely in HD 45975. This provides strong constraints on the excitation/damping of pulsation modes in this HgMn star.

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Orbital solutions for SB2 systems with a HgMn component

Cited by 21 publications

References 28 publications

Chemical spots in the absence of magnetic field in the binary HgMn star 66 Eridani

Chemical spots in the absence of magnetic field in the binary HgMn star 66 Eridani

Testing the companion hypothesis for the origin of the X-ray emission from intermediate-mass main-sequence stars

A search for pulsations in the HgMn star HD 45975 with CoRoT photometry and ground-based spectroscopy

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