Modules

Bohlender, Gerd; Ullrich, Ch.; Gudenberg, Jürgen Wolff von

doi:10.1016/b978-0-12-111155-7.50011-5

Cited by 1 publication

(7 citation statements)

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“…A5 (bottom). HD 37017: Bohlender et al (1987) combined periodograms for photometric and magnetic data and found Prot =0.901195(5) d. This period does not provide a reasonable phasing of the ESPaDONS data. Combining historical measurements with our own, we find 0.901186(2) d. The maximum amplitude period has a FAP of about 10 −7 , while the FAP of the highest-amplitude peak in the Nz spectrum is 0.12.…”

Section: Discussionmentioning

confidence: 88%

“…The Bz curve is fit best with a 3 rd -order sinusoid, which may be indicative of departures from a pure centred dipole. HD 36485: Bz measurements of HD 36485 (δ Ori C) have been published by Bohlender et al (1987), Mathys & Hubrig (1997), Leone et al (2010), and Yakunin et al (2011). ESPaDOnS data is unable to improve the period, which was determined spectroscopically using the magnetic primary's variable Hα emission (Leone et al 2010).…”

Section: Discussionmentioning

confidence: 99%

“…While this period is compatible with the period window of 1.42 to 164 d, we cannot confirm this period using Hipparcos photometry. Bohlender et al (1987) were unable to determine a period for this star due to the negligible variation in Bz . Even at the much higher precision of the ESPaDOnS data, the standard deviation of Bz is only 17 G, with a mean error bar of 28 G. While there are some higher-amplitude peaks at short periods, and very little power at periods longer than ∼10 d, this is likely an artifact caused by the relatively short temporal baseline (56 days, with all but 1 observation acquired within 13 days).…”

Section: Discussionmentioning

confidence: 99%

“…1, bottom). Both stars have longitudinal magnetic fields | Bz | ∼ 1 kG (Bohlender et al 1987;Sikora et al 2015). In such cases multi-line analysis methods such as least-squares deconvolution (LSD) are required in order to measure the star's magnetic field.…”

Section: Magnetometrymentioning

confidence: 99%

“…11 for HD 37776. We compare to photopolarimetric Hβ wing measurements reported in the literature Thompson & Landstreet 1985;Bohlender et al 1987). Mathys et al (2000) showed that, with H profiles calculated with a more accurate treatment of limb darkening and Stark broadening, photopolarimetric Bz measurements made using Hβ lines should be corrected to ∼80% of their published values.…”

Section: H Line Bz Measurementsmentioning

confidence: 99%

See 4 more Smart Citations

The magnetic early B-type stars I: magnetometry and rotation

Shultz

Wade

Rivinius

et al. 2018

Monthly Notices of the Royal Astronomical Society

118

202

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The rotational and magnetic properties of many magnetic hot stars are poorly characterized, therefore the Magnetism in Massive Stars and Binarity and Magnetic Interactions in various classes of Stars collaborations have collected extensive high-dispersion spectropolarimetric data sets of these targets. We present longitudinal magnetic field measurements 〈Bz〉 for 52 early B-type stars (B5–B0), with which we attempt to determine their rotational periods Prot. Supplemented with high-resolution spectroscopy, low-resolution Dominion Astrophysical Observatory circular spectropolarimetry, and archival Hipparcos photometry, we determined Prot for 10 stars, leaving only five stars for which Prot could not be determined. Rotational ephemerides for 14 stars were refined via comparison of new to historical magnetic measurements. The distribution of Prot is very similar to that observed for the cooler Ap/Bp stars. We also measured v sin i and vmac for all stars. Comparison to non-magnetic stars shows that v sin i is much lower for magnetic stars, an expected consequence of magnetic braking. We also find evidence that vmac is lower for magnetic stars. Least-squares deconvolution profiles extracted using single-element masks revealed widespread, systematic discrepancies in 〈Bz〉 between different elements: this effect is apparent only for chemically peculiar stars, suggesting it is a consequence of chemical spots. Sinusoidal fits to H line 〈Bz〉 measurements (which should be minimally affected by chemical spots), yielded evidence of surface magnetic fields more complex than simple dipoles in six stars for which this has not previously been reported; however, in all six cases, the second- and third-order amplitudes are small relative to the first-order (dipolar) amplitudes.

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Section: Discussionmentioning

confidence: 88%