Was the flare on 5 July 1989 a white light flare ?
نویسنده
چکیده
The continuous emission spectra of Hα, Hβ, and Hγ wave bands of the solar flare of 5 July 1989 have been analysed. We demonstrate that the flare not only emits at the line centres and wings of Hα, Hβ, and Hγ, but also in the continuum near these lines. The positions, durations, and configurations of the four flare kernels are respectively similar to those of a white light flare (WLF). Therefore we conclude that this flare was very likely a WLF. The magnetic field of the active region has also been analysed. Most of the flare is located in the vicinity of the neutral line of the magnetic field. Three of the four flare kernels that have continuous emissions lie in the penumbrae of the preceding sunspot and the following sunspot, and near the neutral line, where the magnetic field shears, twists, and shows evidences of having been squeezed or compressed. The fourth kernel of the flare is located in the photospheric region near a small sunspot (about 4′′ in size). The flare kernel with the brightest continuous emission is located at a point where the gradient of the longitudinal magnetic field has maximum value (0.52Gs/Km). Thus the magnetic field at the flare kernels is of two kinds: one showing twist, shear, and possible compression, the other in the photospheric region near a sunspot group or a sunspot. The total energy of the flare is estimated to be about 3.8× 1030 erg.
منابع مشابه
The X 3 Flare of 2002 July 15
An X3-class flare occurred on 2002 July 15 with white-light emission and a complex filament eruption. Observations were made in the optical continuum, H , UV continuum, microwave, and soft X-rays, as well as with high-cadence longitudinal magnetograms. Within the preflare phase, intense heating is observed accompanying upward motion of the filament. At the onset of the impulsive phase, filament...
متن کاملکاربرد الگوریتم ژنتیک و ماشین بردار پشتیبان در جستجوی پارامترهای نانوشرارههای تاج خورشید
Nanoflares are the small impulsive sudden energy releases, due to the explosion of solar background. Thus, determination of their energies and distributions is important . Recent observations and simulation models have shown that the frequency of their energies follows power-law. According to Parker hypothesis, if these exponents are greater than critical value 2, the contributions of nanofla...
متن کامل2 00 5 Footpoint Motion of the Continuum Emission in the 2002 September 30 White - Light Flare
We present observations of the 2002 September 30 white-light flare, in which the optical continuum emission near the Hα line is enhanced by ∼10%. The continuum emission exhibits a close temporal and spatial coincidence with the hard X-ray (HXR) footpoint observed by RHESSI. We find a systematic motion of the flare footpoint seen in the continuum emission; the motion history follows roughly that...
متن کاملA White-light Prominence observed by TRACE
A “white-light prominence” is a flare visible in the continuum above the solar limb. Few examples of this phenomenon have been reported, but the tremendous event of 2003 November 4 was detected by several instruments. This was a partially occulted flare. We report here a detailed study of a much weaker event, seen in this case from a flare whose chromospheric component was on the disk. We find....
متن کاملDo All Flares Have White Light Emission?
High-cadence, multiwavelength optical observations of a solar active region (NOAA 10969), obtained with the Swedish Solar Telescope, are presented. Difference imaging of white light continuum data reveals a white light brightening, 2 min in duration, linked to a co-temporal and co-spatial C2.0 flare event. The flare kernel observed in the white light images has a diameter of 300 km, thus render...
متن کامل