Search Publications
The Nature of Blinkers and the Solar Transition Region
Priest, E. R.; Hood, A. W.; Bewsher, D.
Solar plasma that exists at around 105 K, which has traditionally been referred to as the solar transition region, is probably in a dynamic and fibril state with a small filling factor. Its origin is as yet unknown, but we suggest that it may be produced primarily by one of five different physical mechanisms, namely: the heating of cool…
On Formation of the Sigmoidal Structure in Solar Active Region NOAA 8100
Liu, Y.; Hoeksema, J. T.; Scherrer, P. H. +3 more
Using soft X-ray images taken by the Soft X-ray Telescope on board Yohkoh, line-of-sight magnetograms taken by SOHO/MDI and vector magnetograms taken at Beijing Astronomical Observatory, we have studied the formation of the sigmoidal structure in active region NOAA 8100 on 3-4 November 1997. The sigmoidal structure appeared after the occurrences o…
Polar magnetic fields - Filaments and the zero-flux contour
Durrant, C. J.
We investigate the reliability with which magnetograph observations of the large-scale polar fields establish the zero-flux contour by comparing magnetic maps from various sources with one another and with the locations of filament structures seen on the disk in Hα filtergrams. The daily MWO and NSOKP magnetograms smoothed over 120 arc sec provide…
Study of the nonradial directional property of the rays of the streamer belt and chains in the solar corona
Eselevich, M. V.; Eselevich, V. G.
Based on analyzing corona images taken by the LASCO C1, C2, and C3 instruments, a study is made of the behavior of the streamer belt spanning one half of the 1996-2001 cycle of solar activity, from minimum to maximum activity, in the absence of coronal mass ejections. It is shown that: (1) The position of the streamer belt relative to the solar eq…
The Front-to-Back Asymmetry of Coronal Emission
Andrews, M. D.
Several recent papers have considered the observation of halo coronal mass ejections (CMEs) using the assumption that coronal emission is symmetric with respect to angular position from the Sun. This paper presents a simple but rigorous treatment of the observation of a single electron in the solar corona. The brightness of an electron as a functi…
Short vs Long Time Series : Example of the Solar Diameter
Delmas, C.; Laclare, F.
The significance of a time series obviously changes with its length and accuracy; data about the Sun are no exception. In this short paper, we compare the 23-year long series of visual observations of the solar semi-diameter at Calern Observatory with the activity cycle to find an apparent opposing phase. The comparison of the sub-series of the sa…
The Solar Origin of the 6 January 1997 Coronal Mass Ejection
Dai, Y.; Tang, Y. H.; Wu, Y. Q. +1 more
By using observations from the satellites of the International Solar Terrestrial Physics (ISTP) Observatories, the relationships among the coronal mass ejection (CME), the helmet streamer and the disappearing filament (DSF) have been studied. Our main conclusions are as follows: (1) The DSF disrupted the streamer, thus resulting in the restructuri…
Atmospheric Dynamics and Magnetic Activity Associated With A Coronal Mass Ejection
Zhang, Jun; Wang, Jingxiu; Yang, Zhiliang +1 more
By using multi-wavelength observations, we explored the atmospheric dynamics and the surface magnetic activity in NOAA 9026, which were associated with the initiation of a halo coronal mass ejection (CME) on 6 June, 2000. In an interval of less than two hours, two X-class X-ray flares took place successively, each along with one eruption of a fila…
High-resolution Studies of the Polar Magnetic Fields during Cycle 23
Turner, J.; Varsik, J.; Durrant, C. J. +1 more
High-resolution mosaics of the solar polar magnetic fields have been constructed using individual magnetograms obtained with the video magnetograph of the Big Bear Solar Observatory, and the properties of these mosaics are demonstrated in this paper. The mosaics show selected regions of the polar fields on several days during the rising phase of C…
Limb Prominence Eruption on 11 August 2000 as Seen From Ground- and Space-Based Observations
Abramenko, V. I.; Yurchyshyn, V. B.; Shakhovskaya, A. N.
We report on a prominence eruption as seen in Hα with the Crimean Lyot coronagraph, the global Hα network, and coronal images from the LASCO C2 instrument on board SOHO. We observed an Hα eruption at the northwest solar limb between 07:38:50 UT and 07:58:29 UT on 11 August 2000. The eruption originated in a quiet-Sun region and was not associated …