Large amplitude oscillatory motion along a solar filament

Large amplitude oscillations of solar filaments is a phenomenon known for more than half a century. Recently, a new mode of oscillations, characterized by periodical plasma motions along the filament axis, was discovered. We analyze such an event, recorded on 23 January 2002 in Big Bear Solar Observatory H$\alpha$ filtergrams, in order to infer the triggering mechanism and the nature of the restoring force. Motion along the filament axis of a distinct buldge-like feature was traced, to quantify the kinematics of the oscillatory motion. The data were fitted by a damped sine function, to estimate the basic parameters of the oscillations. In order to identify the triggering mechanism, morphological changes in the vicinity of the filament were analyzed. The observed oscillations of the plasma along the filament was characterized by an initial displacement of 24 Mm, initial velocity amplitude of 51 km/s, period of 50 min, and damping time of 115 min. We interpret the trigger in terms of poloidal magnetic flux injection by magnetic reconnection at one of the filament legs. The restoring force is caused by the magnetic pressure gradient along the filament axis. The period of oscillations, derived from the linearized equation of motion (harmonic oscillator) can be expressed as $P=\pi\sqrt{2}L/v_{A\phi}\approx4.4L/v_{A\phi}$, where $v_{A\phi} =B_{\phi0}/\sqrt{\mu_0\rho}$ represents the Alfv\'en speed based on the equilibrium poloidal field $B_{\phi0}$. Combination of our measurements with some previous observations of the same kind of oscillations shows a good agreement with the proposed interpretation.Comment: Astron. Astrophys., 2007, in pres

The Metaphor of Circle: Stanislavski, Phenomenology of Roundness and High Yoga

Stanislavski’s Eastern influence and his persistent fascination with Yoga is an established area of research. Stanislavski has two major yogic influences in the System: Hatha Yoga and Raja Yoga. The first is about training the body through postures, movements, stances and breathing exercises to make it active, relaxed and energetic. The second includes a range of exclusive practices on concentration and visualization that are an integral part of the actor’s creativity. However, in the current research, there is a clear lack of a comprehensive practical method that informs Stanislavski’s use of yogic practice in the System: what specific yogic exercises were used and what synergies were developed in the training? Scholars have, so far, only explored Stanislavski’s literary legacy of his encounter with yoga, identifying the Sanskrit terms appeared in his writings such as prana for breathing and the Indian anecdotes he used when answering the questions of his students. Focusing on the metaphor of the circle, the phenomenology of roundness and the Deleuzian notions of ‘the invisible forces of sensations’ and ‘the body becomes an event itself’, the present study, for the first time, offers useful insights into the fundamental principles of yoga and their methods of practice as a way of developing a new training to understand the significance of Stanislavski in the 21st century

Soft solar X-rays and solar activity

Minor Hα activity, consisting of small brightenings and small, surgelike spikes, was observed to take place above an active center at the solar limb in good time-association with small fluctuations in the soft X-ray background flux, suggesting that even small dynamical events seen optically are associated with coronal heating. The ratio of Hα flux to soft X-ray flux in some of the surges was approximately the same as the ratio already established for flares. The total energy dissipated by the events in a 24-hour period is estimated; it is approximately equivalent to that released by one flare of imp 1 per day.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43719/1/11207_2004_Article_BF00155785.pd

Soft solar X-rays and solar activity

Soft solar X-rays in the wavelength interval 8–12 Å were observed from OSO III. The totality of the observations that were made between 9 March, 1967, and 18 May, 1968, is summarized graphically and compared to the course of solar activity as observed at other wavelengths, with particular emphasis upon visible activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43715/1/11207_2004_Article_BF00146064.pd

Decay time of type III solar bursts observed at kilometric wavelengths

Type III bursts were observed between 3.5 MHz and 50 kHz by the University of Michigan radio astronomy experiment aboard the OGO-5 satellite.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43731/1/11207_2004_Article_BF00156186.pd

Ancestors and the sun: astronomy, architecture and culture at Chaco Canyon

Three architectural traditions with astronomical associations have been identified among the 'Great Houses' and 'Great Kivas' of Chaco Canyon, New Mexico. Great Houses and one Great Kiva built during the height of construction activity (AD 1020-1100), the Bonito Phase, include front-facing south-southeast (SSE) orientations, and cardinal north-south and/or east-west (NS/EW) alignments. We present ethnographic material supporting our previous proposal that the SSE orientation is probably linked to migration traditions and ancestor veneration. We also confirm that a majority of Late Bonito Phase Great Houses (built after A.D. 1100) exhibit a. third astronomical tradition: five of the principal in-canyon Great Houses built at that time were positioned at or near observing locations that could have functioned as solstice calendrical stations. Through use of these locations for public ceremonies, the Chacoan elite could demonstrate astronomical knowledge and ritual power. These findings provide support for Van Dyke's hypothesis that construction during this period was intended to reinvigorate a faltering system. One 'Chaco halo' Great House, Bis sa'ani, incorporates all three traditions. We suggest that temporal analysis of these traditions improves understanding of migration paths and shifting balances of power and social dominance among ancestral Pueblo culture groups

Ancestors and the sun: astronomy, architecture and culture at Chaco Canyon

Three architectural traditions with astronomical associations have been identified among the 'Great Houses' and 'Great Kivas' of Chaco Canyon, New Mexico. Great Houses and one Great Kiva built during the height of construction activity (AD 1020-1100), the Bonito Phase, include front-facing south-southeast (SSE) orientations, and cardinal north-south and/or east-west (NS/EW) alignments. We present ethnographic material supporting our previous proposal that the SSE orientation is probably linked to migration traditions and ancestor veneration. We also confirm that a majority of Late Bonito Phase Great Houses (built after A.D. 1100) exhibit a. third astronomical tradition: five of the principal in-canyon Great Houses built at that time were positioned at or near observing locations that could have functioned as solstice calendrical stations. Through use of these locations for public ceremonies, the Chacoan elite could demonstrate astronomical knowledge and ritual power. These findings provide support for Van Dyke's hypothesis that construction during this period was intended to reinvigorate a faltering system. One 'Chaco halo' Great House, Bis sa'ani, incorporates all three traditions. We suggest that temporal analysis of these traditions improves understanding of migration paths and shifting balances of power and social dominance among ancestral Pueblo culture groups