No evidence of a sudden change of spectral appearance or magnetic field strength of the O9.7V star HD 54879

Abstract It was recently claimed that the magnetic O-type star HD 54879 exhibits important radial velocity variability indicative of its presence in a spectroscopic binary. More remarkably, it was furthermore reported that the star underwent a short, sudden variation in spectral type and magnetic field. In this Letter we examine new Narval and ESPaDOnS data of this star in addition to the previously-published FORS2 data and conclude that both the reported velocity variations and the sudden spectral and magnetic changes are spurious.

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On the Configuration of the Magnetic Field of β CrB

International Astronomical Union Colloquium ◽

10.1017/s0252921100080933 ◽

1976 ◽

Vol 32 ◽

pp. 613-622

Author(s):

I.A. Aslanov ◽

Yu.S. Rustamov

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Radial Velocity ◽

Magnetic Field Strength ◽

Complex Shape ◽

Rotation Period ◽

Field Variation ◽

Magnetic Field Variation ◽

Secular Variations ◽

The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

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Determination of Stellar Magnetism Based on the Computerized Evaluation of Zeeman-Spectra

International Astronomical Union Colloquium ◽

10.1017/s0252921100020637 ◽

1993 ◽

Vol 138 ◽

pp. 291-294

Author(s):

Ewald Gerth

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Radial Velocity ◽

Magnetic Field Strength ◽

Stellar Spectra ◽

Data Files ◽

Line Positions ◽

The Magnetic Field ◽

Electronic Detector

AbstractA package of computer-programs is presented, which is suited for the evaluation of stellar spectra in regard of line positions in order to determine the magnetic field strength and the radial velocity. The programs have been developed for the calculation of the measuring data obtained from photographic spectrograms but could be generalized for the online observation in a spectrograph at the telescope using an electronic detector.The network of programs may be amplified deliberately as required for any special application. For the exchange of data among cooperating institutes we propose the standardization of programs and data-files as outlined below.

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Suppress of neurotransduction in injured spinal cord of rats with moderate magnetic field strength

Neuroscience Research ◽

10.1016/s0168-0102(00)81259-6 ◽

2000 ◽

Vol 38 ◽

pp. S69

Author(s):

H Tatsuoka

Keyword(s):

Magnetic Field ◽

Spinal Cord ◽

Field Strength ◽

Magnetic Field Strength ◽

Injured Spinal Cord ◽

Moderate Magnetic Field

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2D analysis of magnetic field strength in GO SiFe steel sheets

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:19982133 ◽

1998 ◽

Vol 08 (PR2) ◽

pp. Pr2-579-Pr2-582 ◽

Cited By ~ 1

Author(s):

S. Tumanski ◽

M. Stabrowski

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Steel Sheets

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MAGNETIC FIELD, PRESSURE AND TEMPERATURE DEPENDENT OPTICAL PROPERTIES IN A GaAs 9.0 P 1.0 QUANTUM DOT

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v6i2.1791 ◽

2014 ◽

Vol 6 (2) ◽

pp. 1178-1190

Author(s):

A. JOHN PETER ◽

Ada Vinolin

Keyword(s):

Magnetic Field ◽

Optical Properties ◽

Quantum Dot ◽

Field Strength ◽

Magnetic Field Strength ◽

Photon Energy ◽

Nonlinear Optical ◽

Binding Energies ◽

Nonlinear Optical Properties ◽

Optical Rectification

Simultaneous effects of magnetic field, pressure and temperature on the exciton binding energies are found in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot. Numerical calculations are carried out taking into consideration of spatial confinement effect. The cylindrical system is taken in the present problem with the strain effects. The electronic properties and the optical properties are found with the combined effects of magnetic field strength, hydrostatic pressure and temperature values. The exciton binding energies and the nonlinear optical properties are carried out taking into consideration of geometrical confinement and the external perturbations.Compact density approach is employed to obtain the nonlinear optical properties. The optical rectification coefficient is obtained with the photon energy in the presence of pressure, temperature and external magnetic field strength. Pressure and temperature dependence on nonlinear opticalÂ susceptibilities of generation of second and third order harmonics as a function of incident photon energy are brought out in the influence of magnetic field strength. The result shows that the electronic and nonlinear optical properties are significantly modified by the applications of external perturbations in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot.

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