High-Resolution Extreme-Ultraviolet Solar Spectrum Recorded with a Diffraction-Filter Spectrograph

1971 ◽  
Vol 169 ◽  
pp. L27 ◽  
Author(s):  
W. Schweizer ◽  
G. Schmidtke
1970 ◽  
Vol 36 ◽  
pp. 271-273
Author(s):  
B. B. Jones ◽  
B. C. Boland ◽  
R. Wilson ◽  
S. T. F. Engstrom

A high-resolution solar spectrum in the range 2000–2200 Å was obtained in a recent flight of a sunpointing Skylark rocket. This was launched at 04.21 hr UT on April 22, 1969 from Woomera and reached an apogee of 178 km. An optical alignment system operating on the main vehicle pointing system gave a net stabilisation of ±3 arc sec in the position of the solar image relative to the spectrograph slit. The slit, of length 1.0 mm, was set in the north-east quadrant parallel to and 5 arc min from the north/south axis, its lower edge being 1 arc min from the equator. The roll control of ±2.5° was provided entirely by the standard Elliott Bros. type of vehicle stabilisation.


1999 ◽  
Vol 9 (2) ◽  
pp. 3330-3333 ◽  
Author(s):  
S. Friedrich ◽  
J.B. Le Grand ◽  
L.J. Hiller ◽  
J. Kipp ◽  
M. Frank ◽  
...  

2018 ◽  
Vol 615 ◽  
pp. A47 ◽  
Author(s):  
Srividya Subramanian ◽  
Vinay L. Kashyap ◽  
Durgesh Tripathi ◽  
Maria S. Madjarska ◽  
John G. Doyle

We study the thermal structure and energetics of the point-like extreme ultraviolet (EUV) brightenings within a system of fan loops observed in the active region AR 11520. These brightenings were simultaneously observed on 2012 July 11 by the High-resolution Coronal (Hi-C) imager and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). We identified 27 brightenings by automatically determining intensity enhancements in both Hi-C and AIA 193 Å light curves. The energetics of these brightenings were studied using the Differential Emission Measure (DEM) diagnostics. The DEM weighted temperatures of these transients are in the range log T(K) = 6.2−6.6 with radiative energies ≈1024−25 ergs and densities approximately equal to a few times 109 cm−3. To the best of our knowledge, these are the smallest brightenings in EUV ever detected. We used these results to determine the mechanism of energy loss in these brightenings. Our analysis reveals that the dominant mechanism of energy loss for all the identified brightenings is conduction rather than radiation.


1959 ◽  
Vol 64 ◽  
pp. 133
Author(s):  
R. R. Tousey ◽  
J. D. Purcell ◽  
D. M. Packer ◽  
W. R. Hunter

2012 ◽  
Vol 101 (9) ◽  
pp. 093104 ◽  
Author(s):  
Li Wang ◽  
Bernd Terhalle ◽  
Vitaliy A. Guzenko ◽  
Alan Farhan ◽  
Mohamad Hojeij ◽  
...  

2021 ◽  
Author(s):  
Martin Snow ◽  
Stephane Beland ◽  
Odele Coddington ◽  
Steven Penton ◽  
Don Woodraska

<p>The GOES-R series of satellites includes a redesigned instrument for solar spectral irradiance: the Extreme ultraviolet and X-ray Irradiance Sensor (EXIS).  Our team will be using a high-cadence broadband visible light diode to construct a proxy for Total Solar Irradiance (TSI).  This will have two advantages over the existing TSI measurements:  measurements are taken at 4 Hz, so the cadence of our TSI proxy is likely faster than any existing applications, and the observations are taken from geostationary orbit, so the time series of measurements is virtually uninterrupted.  Calibration of the diode measurements will still rely on the standard TSI composites.  </p><p>The other measurement from EXIS that will be used is the Magnesium II core-to-wing ratio.  The MgII index is a proxy for chromospheric activity, and is measured by EXIS every 3 seconds.  The combination of the two proxies can be used to generate a model of the full solar spectrum similar to the NRLSSI2 empirical model.</p><p>We are in the first year of a three-year grant to develop the TSI proxy and the SSI model, so only very preliminary findings will be discussed in this presentation.</p>


1997 ◽  
pp. 123-141
Author(s):  
R. A. Harrison ◽  
A. Fludra ◽  
C. D. Pike ◽  
J. Payne ◽  
W. T. Thompson ◽  
...  

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