scholarly journals Twisting flux tubes as a cause of micro-flaring activity

2007 ◽  
Vol 3 (S247) ◽  
pp. 360-363
Author(s):  
D. B. Jess ◽  
R. T. J. McAteer ◽  
M. Mathioudakis ◽  
F. P. Keenan ◽  
A. Andic ◽  
...  
Keyword(s):  
Solar Observatory ◽  
Optical Observations ◽  
Bright Point ◽  
Solar Telescope ◽  
Camera System ◽  
Flux Tubes ◽  
National Solar Observatory ◽  
Blue Wing ◽  
Significance Levels ◽  
High Cadence

AbstractHigh-cadence optical observations of an H-α blue-wing bright point near solar AR NOAA 10794 are presented. The data were obtained with the Dunn Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly developed camera system, the rapid dual imager. Wavelet analysis is undertaken to search for intensity-related oscillatory signatures, and periodicities ranging from 15 to 370 s are found with significance levels exceeding 95%. During two separate microflaring events, oscillation sites surrounding the bright point are observed to twist. We relate the twisting of the oscillation sites to the twisting of physical flux tubes, thus giving rise to reconnection phenomena. We derive an average twist velocity of 8.1 km/s and detect a peak in the emitted flux between twist angles of 180° and 230°.

scholarly journals Signature of collision of magnetic flux tubes in the quiet solar photosphere

2010 ◽  
Vol 6 (S273) ◽  
pp. 399-402
Author(s):  
Aleksandra Andic
Keyword(s):  
Magnetic Flux ◽  
Spectral Line ◽  
Solar Observatory ◽  
Bright Point ◽  
Solar Photosphere ◽  
Solar Telescope ◽  
Weak Current ◽  
Flux Tubes ◽  
Oscillatory Power ◽  
Magnetic Flux Tubes

AbstractCollision of the magnetic flux tubes in the Quiet Sun was proposed as one of the possible sources for the heating of the solar atmosphere (Furusawa and Sakai, 2000). The solar photosphere was observed using the New Solar Telescope ad Big Bear Solar Observatory. In TiO spectral line at 705.68 nm we approached resolution of 0.1″. The horizontal plasma wave was observed spreading from the larger bright point. Shorty after this wave an increase in the oscillatory power appeared at the same location as the observed bright point. This behavior matches some of the results from the simulation of the collision of the two flux tubes with a weak current.

scholarly journals High-Resolution Observations of Emerging Magnetic Fields and Flux Tubes in Active Region Photosphere

1990 ◽  
Vol 138 ◽  
pp. 147-152 ◽  
Author(s):  
T. Tarbell ◽  
S. Ferguson ◽  
Z. Frank ◽  
R. Shine ◽  
A. Title ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Solar Observatory ◽  
Disk Center ◽  
Line Center ◽  
Solar Photosphere ◽  
Flux Tubes ◽  
National Solar Observatory ◽  
La Palma ◽  
The Relationship

On 29 September 1988, filtergrams of the solar photosphere with excellent resolution (0.3 to 0.5 arcsecond) were obtained at the Swedish Solar Observatory on La Palma, Canary Islands. An outstanding 2.5 hour run of digital filtergram observations was obtained, looking at a small area within an active region near disk center. On 6 August 1987, an 80 minute run of similar observations was obtained at the Vacuum Tower Telescope of the National Solar Observatory at Sacramento Peak. Digital and video movies have been made of Dopplergrams, magnetograms, line center, continuum, and white light images. Several examples of magnetic field emergence and formation of flux tubes can be studied in detail in the movies. The relationship between photospheric bright points, “filigree”, the line center brightness, and the magnetic field has been established for individual images in analysis to date.

Two-telescope-based solar seeing profile measurement simulation

2022 ◽  
Vol 21 (12) ◽  
pp. 298
Author(s):  
Zi-Yue Wang ◽  
De-Qing Ren ◽  
Raffi Saadetian
Keyword(s):  
Numerical Simulations ◽  
Atmospheric Turbulence ◽  
Adaptive Optics ◽  
Solar Observatory ◽  
Performance Estimation ◽  
Image Motion ◽  
Profile Measurement ◽  
Solar Telescope ◽  
National Solar Observatory ◽  
Bear Lake

Abstract Measurements of the daytime seeing profile of the atmospheric turbulence are crucial for evaluating a solar astronomical site so that research on the profile of the atmospheric turbulence as a function of altitude C n 2 ( h n ) becomes more and more critical for performance estimation and optimization of future adaptive optics (AO) including the multi-conjugate adaptive optics (MCAO) systems. Recently, the S-DIMM+ method has been successfully used to measure daytime turbulence profiles above the New Solar Telescope (NST) on Big Bear Lake. However, such techniques are limited by the requirement of using a large solar telescope which is not realistic for a new potential astronomical site. Meanwhile, the A-MASP (advanced multiple-aperture seeing profiler) method is more portable and has been proved that can reliably retrieve the seeing profile up to 16 km with the Dunn Solar Telescope (DST) on the National Solar Observatory (Townson, Kellerer et al.). But the turbulence of the ground layer is calculated by combining A-MASP and S-DIMM+ (Solar Differential Image Motion Monitor+) due to the limitation of the two-individual-telescopes structure. To solve these problems, we introduce the two-telescope seeing profiler (TTSP) which consists of two portable individual telescopes. Numerical simulations have been conducted to evaluate the performance of TTSP. We find our TTSP can effectively retrieve seeing profiles of four turbulence layers with a relative error of less than 4% and is dependable for actual seeing measurement.

scholarly journals High frequency oscillations in the solar chromosphere and their connection with heating

2007 ◽  
Vol 3 (S247) ◽  
pp. 312-315 ◽  
Author(s):  
Aleksandra Andic ◽  
M. Mathioudakis ◽  
F. P. Keenan ◽  
D. B. Jess ◽  
D. S. Bloomfield
Keyword(s):  
Magnetic Fields ◽  
Acoustic Waves ◽  
High Frequency ◽  
Solar Observatory ◽  
Solar Chromosphere ◽  
Frequency Interval ◽  
Solar Telescope ◽  
National Solar Observatory ◽  
High Frequency Oscillations ◽  
Using Data

AbstractHigh frequency acoustic waves have been suggested as a source of mechanical heating in the quiet solar chromosphere. To investigate this, we have observed intensity oscillations of several lines in the frequency interval 1.64-70mHz using data from the VTT Tenerife and the Dunn Solar Telescope at the National Solar Observatory. Our analysis of Fe i 543.45 nm, Fe i 543.29 nm and the G-band, indicate that the majority of oscillations are connected with the magnetic fields and do not provide sufficient mechanical flux for the heating of the chromosphere. This correlation is also observed in quiet Sun areas.

scholarly journals Infrared heterodyne spectroscopy: a tool for helioseismology

1988 ◽  
Vol 123 ◽  
pp. 481-484
Author(s):  
D.A. Glenar ◽  
H.U. Käufl ◽  
D. Deming ◽  
T. Kostiuk ◽  
M.J. Mumma
Keyword(s):  
Doppler Shift ◽  
Single Point ◽  
Solar Observatory ◽  
Solar Telescope ◽  
Solar Oscillation ◽  
Velocity Measurements ◽  
National Solar Observatory ◽  
Heterodyne Spectroscopy ◽  
Heterodyne Spectrometer ◽  
Absorption Features

Heterodyne spectroscopy at infrared (IR) wavelengths is a technique well suited for measuring small velocities in the solar atmosphere. An IR heterodyne spectrometer for solar oscillation measurements has been located at the McMath Solar Telescope of the Kitt Peak National Solar Observatory. It is now being used for single point Doppler shift measurements of 11 micron OH absorption features formed in the upper photosphere, with sampling rates as high as 33 mHz. The instrument employs a stabilized CO2. laser permitting absolute velocity measurements with an uncertainty of < 10 ms−1.

scholarly journals Substructure of quiet sun bright points

2010 ◽  
Vol 6 (S273) ◽  
pp. 339-342
Author(s):  
Aleksandra Andic ◽  
Jongchul Chae ◽  
Phillip R. Goode
Keyword(s):  
Solar Observatory ◽  
Solar Telescope ◽  
Surface Photometry ◽  
Flux Tubes ◽  
Quiet Sun ◽  
The Individual ◽  
Average Size

AbstractSince photospheric bright points (BPs) were first observed, there has been a question as to how are they structured. Are they just single flux tubes or a bundle of the flux-tubes? Surface photometry of the quiet Sun (QS) has achieved resolution close to 0.1″ with the New Solar Telescope at Big Bear Solar Observatory. This resolution allowed us to detect a richer spectrum of BPs in the QS. The smallest BPs we observed with TiO 705.68 nm were 0.13″, and we were able to resolve individual components in some of the BPs clusters and ribbons observed in the QS, showing that they are composed of the individual BPs. Average size of observed BPs was 0.22″.

The infrared spectrum of CS

1984 ◽  
Vol 62 (12) ◽  
pp. 1414-1419 ◽  
Author(s):  
R. J. Winkel Jr. ◽  
Sumner P. Davis ◽  
Rubén Pecyner ◽  
James W. Brault
Keyword(s):  
Fourier Transform ◽  
Infrared Emission ◽  
Solar Observatory ◽  
Band Head ◽  
The Other ◽  
Fourier Transform Spectrometer ◽  
National Solar Observatory ◽  
Carbon Monosulfide ◽  
Vibration Rotation ◽  
The Fourier Transform

The infrared emission spectrum of carbon monosulfide was observed as a sequence of vibration–rotation bands in the X1Σ+ state, with strong heads of the Δν = 2 sequence degraded to the red. Eight bands of 12C32S were identified, and bands corresponding to the isotope 12C34S were also observed. The most prominent band head, that of the (2–0) band, is at 2585 cm−1, with the other heads spaced approximately 26 cm−1 to smaller wavenumbers. Our data, taken with the Fourier transform spectrometer at the National Solar Observatory (Kitt Peak) include the first reported laboratory observations of the band heads and as many as 200 lines in each band. These observations allowed the calculation of vibrational and rotational constants to higher order than previously reported.

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