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A new vectormagnetograph is described that measures all components of the magnetic field vector strictly simultaneously. The azimuth of the direction of the field is continuously obtained during the observation by means of a servo circuit. As a first step of data recording a photographic method is applied which presents all 5 quantities (longitudinal and transverse component of the field vector, azimuth, Doppler shift and intensity) in the form of maps.Several methods of calibration are discussed in detail. For stronger fields the calibration turns out to be particularly difficult.The sensitivity obtained is 4 gauss using a scanning spot of 3 × 3 and a time constant of 1 sec. This value agrees with the shot-noise of the multipliers which can be inferred by taking the light transmittance of the whole instrument into consideration.Transverse fields have been measured with a sensitivity of 130 gauss (300 gauss, if the random deviation of the azimuth is < 10°). In this case the scanning spot covered 5 × 5, the time constant being 3 sec.A series of vectormagnetograms is presented which was obtained during a 2B-flare event in a centre of activity. The field configuration is discussed with regard to the position of the flare.Mitteilungen aus dem Fraunhofer Institut Nr. 87. 相似文献
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Franz-Ludwig Deubner 《Solar physics》1971,17(1):6-20
Photoelectric measurements of Doppler shifts of various Fraunhofer lines obtained with the Capri magnetograph were analysed. The height dependence of the supergranular and oscillatory motions, as well as the two dimensional structure of these velocity fields is investigated. The most interesting results are the following:
- The oscillatory and supergranular motions are still clearly present in very deep photospheric layers as detected e.g. by means of the Ci line at 5380.3 Å.
- Whereas the vertical motions (both of oscillation and supergranulation) increase with height, the horizontal component of the supergranular flow is found to be decreasing slightly.
- Aperiodic horizontal motions are observed in the photospheric layers, which are probably connected with the process of excitation of the oscillatory field.
- There is no simple way of describing the oscillatory field in terms of independently oscillating ‘cells’, since the two-dimensional pattern changes its appearance drastically already in a fraction of one oscillation period.
- The correlation obtained by previous observers between vertical stationary motions, the chromospheric network and magnetic fields in particular is confirmed.
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Photoelectric polarisation measurements in a stable sunspot (type H) with a particularly dark umbra carried out with the Capri magnetograph have been evaluated in terms of Unno's (1956) theory to give the value and direction of the magnetic field vector. A linear increase of the inclination angle with distance from the spot centre up tor 1.2R
s results, as originally found by Hale and Nicholson (1938) with a different procedure. The field strength decreases from the maximum value (about 3300) to about 15% at the penumbral border, still continuously decreasing outside the spot. The projected field direction deviates considerably from the radial symmetry in several parts of the spot region, but it is in good agreement with that of the overlaying chromospheric structures.Mitteilungen aus dem Fraunhofer Institut Nr. 97. 相似文献
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New observations of the photospheric 5-min oscillations are presented which prove that the physical reality of the very high horizontal phase propagation velocities observed in connection with the oscillations cannot be maintained. Instead, a statistical model is proposed to explain the observed phase relations.Mitteilungen aus dem Fraunhofer Institut Nr. 119. 相似文献
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Solar Physics - Short period oscillations (with periods less than 150 s) are shown to be non-uniformly distributed on the solar surface, and in time. Rather, they appear concentrated in short... 相似文献
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Franz-Ludwig Deubner 《地球物理与天体物理流体动力学》2013,107(1-4):153-172
Abstract The most recent observational activities and results in the field of solar oscillations are reviewed. We address the dynamics and structure of the solar interior and of the atmosphere up to the transition layer, while global, local and atmospheric oscillations are being discussed. The topics of this review include: line width and amplitude limits of the p-modes; cycle variations of frequencies and amplitudes; internal solar rotation rate; p-mode absorption in spots and antipodal focussing of p-modes; diagnostics in the UV and in the IR; phase diagnostics in the atmosphere; chromospheric bright points. 相似文献
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A minimum of angular velocity is not found at the equator as suggested by Gilman, but at a latitude of 6° in both hemispheres. 相似文献