206
206
Jul 11, 2010
07/10
by
Green, K. S.; Putnam, T. W
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Sonic booms generated by the X-15 airplane flying at Mach numbers of 3.5 and 4.8 were measured. The experimental results agreed within 12 percent with results obtained from theoretical methods. No unusual phenomena related to overpressure were encountered. Scaled data from the X-15 airplane for Mach 4.8 agreed with data for an SR-71 airplane operating at lower Mach numbers and similar altitudes. The simple technique used to scale the data on the basis of airplane lift was satisfactory for...
Topics: SOLAR ACTIVITY, SOLAR PHYSICS, SUNSPOTS, SPECTROHELIOGRAPHS, ASTRONOMICAL MODELS, CHROMOSPHERE, H...
198
198
May 22, 2011
05/11
by
Bourbakis, N. G.; Maas, M.; Tascillo, A.; Vandewinckel, C
texts
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ODYSSEUS is an autonomous walking robot, which makes use of three wheels and three legs for its movement in the free navigation space. More specifically, it makes use of its autonomous wheels to move around in an environment where the surface is smooth and not uneven. However, in the case that there are small height obstacles, stairs, or small height unevenness in the navigation environment, the robot makes use of both wheels and legs to travel efficiently. In this paper we present the detailed...
Topics: DATA REDUCTION, MAGNETOMETERS, SOLAR INSTRUMENTS, SOLAR OBSERVATORIES, TELESCOPES, COMPUTER...
Draft versions of three articles submitted for publication are presented. The first two articles address high resolution X-ray images of early type galaxies observed with the ROSAT HRI and PSPC. Data for NGC 1553 and NGC 5846 indicate that the emission is highly irregular, with interesting features at different scales. The gas temperatures also vary both with the galactocentric radius and in correspondence to regions of higher emission and denser material. Strikingly similar features are...
Topics: NASA Technical Reports Server (NTRS), INTERSTELLAR MATTER, GALAXIES, X RAY ASTRONOMY, ROSAT...
160
160
May 31, 2011
05/11
by
Chambers, Lin H.; Lin, Bing; Young, David F
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New data products are available from the CERES instrument, a part of the NASA Earth Observing System. The Single Scanner Footprint (SSF) product combines radiative fluxes with extensive information on the cloud conditions in the footprint, which are retrieved using the co-orbiting imager instrument. These data have been analyzed to more accurately define the radiative properties for the various regions of the recently-proposed adaptive infrared Iris. A variety of ways of defining the cloudy...
Topics: GALACTIC CLUSTERS, STAR FORMATION, ULTRAVIOLET EMISSION, IMAGING TECHNIQUES, X RAYS, STELLAR...
A series of flares was studied in McMath 11482 August 19-22, 1971, with particular reference to the basis for the flares and comparison with dekameter radio data. The flares were produced by rapid (approximately 1000 km/hr) westward motion of a large new p spot. Many flares occur just in front of the spot, and they cease when the motion stops. All flares occuring in front of the spot produce type III bursts, while even strong flares elsewhere in the region produce little or no type III. The...
Topics: NASA Technical Reports Server (NTRS), SOLAR FLARES, SUNSPOTS, H ALPHA LINE, SOLAR RADIATION, TYPE 3...
A study of the stellar wind properties of O-type close binary systems is presented. The main objective of this program was to search for colliding winds in four systems, AO Cas, iota Ori, Plaskett's star, and 29 UW CMa, through an examination of high dispersion UV spectra from IUE and optical spectra of the H alpha and He I lambda 6678 emission lines.
Topics: NASA Technical Reports Server (NTRS), BINARY STARS, EMISSION SPECTRA, STELLAR WINDS, ULTRAVIOLET...
Far Ultraviolet Spectroscopic Explorer (FUSE) observations at four positions across a faint H-alpha filament in the northern Cygnus Loop were carried out successfully. The O(VI) profiles were measured in the four spectra, and we are in the process of fitting them. We have constructed models for a rippled sheet of emission seen almost edge-on based on non-radiative shock wave models for the time-dependent ionization state of the gas behind the shock. The function that describes the rippled sheet...
Topics: NASA Technical Reports Server (NTRS), FLUORESCENCE, GAS IONIZATION, RADIATIVE TRANSFER, H ALPHA...
The 1349 study flares are considered addressing relationships between pairs of specific study paremeters; namely, H alpha rise time versus H alpha importance, X-ray class and H alpha decay time; H alpha decay time versus H alpha importance and X-ray class; and H alpha importance versus X-ray class. Mean H alpha rise time and decay time versus X-ray class and H alpha importance will also be discussed, and some final comments regarding the study flares are given.
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, SOLAR FLARES, STATISTICAL ANALYSIS, SOLAR...
An analysis is presented of data on the km-wave type-3 bursts associated with H alpha flares. A list of published papers based on previous analysis is also presented.
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, OGO-5, TYPE 3 BURSTS, EXPLORER 43 SATELLITE,...
Coude spectra of kappa CMa in the red region showed H alpha and He 1 lambda lambda 5876,6678 in emission. Each of the lines had two emission components, but the helium lines had no detectable absorption feature in between. While the H alpha emission peaks were separated by 160 km/sec, the helium lines were separated by 400 km/sec. A simple model is proposed to account for the behavior of these emission lines.
Topics: NASA Technical Reports Server (NTRS), HELIUM, SPECTRAL EMISSION, STELLAR SPECTRA, ABSORPTION...
1,253
1.3K
Jul 23, 2010
07/10
by
Yates, E. Carson, Jr
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To promote the evaluation of existing and emerging unsteady aerodynamic codes and methods for applying them to aeroelastic problems, especially for the transonic range, a limited number of aerodynamic configurations and experimental dynamic response data sets are to be designated by the AGARD Structures and Materials Panel as standards for comparison. This set is a sequel to that established several years ago for comparisons of calculated and measured aerodynamic pressures and forces. This...
Topics: CHROMOSPHERE, SOLAR FLARES, ULTRAVIOLET PHOTOGRAPHY, MAGNETIC FIELD CONFIGURATIONS, PHOTOSPHERE,...
Solar activity during the period October 28, 1964 through August 27, 1965 is presented in the form of charts for each solar rotation constructed from observations made with the chromospheric H-alpha spectra line. These H-alpha synoptic charts are identical in format and method of construction to those published for the period of Skylab observations. The sunspot minimum marking the start of Solar Cycle 20 occurred in October, 1964; therefore, charts represent solar activity during the first year...
Topics: NASA Technical Reports Server (NTRS), GRAPHS (CHARTS), SKYLAB PROGRAM, SOLAR ACTIVITY, SOLAR...
A power spectral analysis of 285 hr of 2 cm microwave intensity data showed no statistically significant ( 96% confidence) periodicities in the frequency range 1 to 15 mHz. No correlation was found between 2 cm periodicities and solar activity in H alpha, X-ray, and several microwave frequencies. A small shift of power toward higher frequencies in the power spectrum of the 2 cm data was found to be correlated with solar H alpha and X-ray activity. Using the statistical properties of power...
Topics: NASA Technical Reports Server (NTRS), MICROWAVES, POWER SPECTRA, SOLAR ACTIVITY, SPECTRUM ANALYSIS,...
A survey of the statistical properties of 850 H alpha solar flares during 1975 is presented. Comparison of the results found here with those reported elsewhere for different epochs is accomplished. Distributions of rise time, decay time, and duration are given, as are the mean, mode, median, and 90th percentile values. Proportions by selected groupings are also determined. For flares in general, mean values for rise time, decay time, and duration are 5.2 + or - 0.4 min, and 18.1 + or 1.1 min,...
Topics: NASA Technical Reports Server (NTRS), SOLAR FLARES, SOLAR PROMINENCES, STATISTICAL ANALYSIS,...
A description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility is provided, and a summary of its observations and data reduction during Oct. - Dec. 1990 is presented. The systems that make up the facility are a magnetograph telescope, and H-alpha telescope, a Questar telescope, and a computer code. The data are represented by longitudinal contours with azimuth plots.
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, MAGNETOMETERS, SOLAR MAGNETIC FIELD, SOLAR...
I review photo-polarimetric and spectropolarimetric observations of V838 Mon, which revealed that it had an asymmetrical inner circumstellar envelope following its 2nd photometric outburst. Electron scattering, modified by preor post-scattering H absorption, is the polarizing mechanism in V838 Mon's envelope. The simplest geometry implied by these observations is that of a spheroidal shell, flattened by at least 20% and having a projected position angle on the sky of approx. 37 degrees....
Topics: NASA Technical Reports Server (NTRS), POLARIMETERS, PHOTOMETERS, ASTROPHYSICS, STELLAR ENVELOPES,...
Coronal and interplanetary magnetic fields computed from measurements of large-scale photospheric magnetic fields suffer from interruptions in day-to-day observations and the limitation of using only measurements made near the solar central meridian. Procedures were devised for inferring the lines of polarity reversal from H-alpha solar patrol photographs that map the same large-scale features found on Mt. Wilson magnetograms. These features may be monitored without interruption by combining...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL PHOTOGRAPHY, H ALPHA LINE, INTERPLANETARY...
This report provides a description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility and gives a summary of its observations and data reduction during July-December 1992. The systems that make up the facility are a magnetograph telescope, an H-alpha telescope, a Questar telescope, and a computer code.
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, DATA REDUCTION, MAGNETIC SIGNATURES,...
This report provides a description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility and gives a summary of its observations and data reduction during January-June 1993. The systems that make up the facility are a magnetograph telescope, an H-alpha telescope, a Questar telescope, and a computer code.
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, DATA REDUCTION, MAGNETOMETERS, NASA...
A description of the NASA Marshall Space Flight C nter's Solar Vector Magnetograph Facility is provided and gives a summary of its observations and data reduction during Jul. - Sep. 1990. The systems that make up the facility are a magnetograph telescope, an H-alpha telescope, a Questar telescope, and a computer code. The data are represented by longitudinal contours with azimuth plots.
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, MAGNETOMETERS, SOLAR MAGNETIC FIELD, SOLAR...
159
159
May 6, 2010
05/10
by
Tsap, T. T
texts
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Magnetic field and fine structure of chromosphere in active region of sun
Topics: CHROMOSPHERE, CHROMOSPHERE, FINE STRUCTURE, SOLAR MAGNETIC FIELD, SUN, FINE STRUCTURE, H ALPHA...
Solar spicules appear as narrow jets emanating from the chromosphere and extending into the corona. They have been observed for over a hundred years, mainly in chromospheric spectral lines such as H-alpha. Because they are at the limit of visibility of ground-based instruments, their nature has long been a puzzle. In recent years however, vast progress has been made in understanding them both theoretically and observationally, as spicule studies have undergone a revolution because of the...
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, LINE SPECTRA, SPICULES, SATELLITE-BORNE...
A description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility is presented and a summary of its observations and data reduction is given. The systems that make up the facility are a magnetograph telescope, an H alpha telescope, a Questar telescope, and a computer code. The data are represented by longitudinal contours with azimuth plots.
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, H ALPHA LINE, MAGNETIC SIGNATURES, SOLAR...
This report provides a description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility and gives a summary of its observations and data reduction during June-October 1993. The systems that make up the facility are a magnetograph telescope, an H-alpha telescope, a Questar telescope, and a computer code.
Topics: NASA Technical Reports Server (NTRS), DATA REDUCTION, MAGNETOMETERS, SOLAR INSTRUMENTS, SOLAR...
The preflight preparation of the multilayer mirror fabrication and testing, integration and testing, and WSMR activities are described. Post-flight analysis shows that all payload systems and subsystems performed well within acceptable limits, with the sole exception of the light-blocking prefilters. Suggested corrective actions were discussed. Refurbishment and reflight are then described.
Topics: NASA Technical Reports Server (NTRS), PERFORMANCE TESTS, POSTFLIGHT ANALYSIS, SOLAR CORONA, X RAY...
The phenomenon of the sudden filament disappearance (Disparition Brusque) is a familiar one to observers at H alpha telescopes. Nevertherless, the importance in Disparition Brusques (DB) continues to grow for several reasons which are cited in the discussion. It is reported that there seems to be more interest on building and maintain filaments than in destroying them. As a consequence, this sub-group is smaller than most of the others. All the same, progress in this area of filament...
Topics: NASA Technical Reports Server (NTRS), CORONAL LOOPS, H ALPHA LINE, SOLAR MAGNETIC FIELD, SOLAR...
AII1349 H alpha flares occurring in 1980 which have known start, maximum brightness, and end times, latitudes, and associated importance and X-ray classes were used to perform a statistical study of flare rise time, decay time, duration, latitude, importance (areal and relative intensity), and X-ray class. Frequency distributions of these parameters are tabulated and plotted.
Topics: NASA Technical Reports Server (NTRS), DATA BASES, FREQUENCY DISTRIBUTION, H ALPHA LINE, SOLAR...
538
538
May 23, 2011
05/11
by
NON
texts
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During the current research period, an updated users manual was written for the ASTROP2 code. ASTROP2 is an aeroelastic code based on the two- dimensional linear unsteady aerodynamic equations, and the three-dimensional structural dynamic equations. The original program was modified, and extended, which also required the writing of a new users manual. The manual was published as NASA TM 107195. The multistage code was modified and applied to predict the gust response for the turbine airfoils....
Topics: SUPERNOVA 1987A, RESONANCE SCATTERING, FLUORESCENCE, RECOMBINATION COEFFICIENT, TEMPERATURE...
Gravitational interactions between galaxies are believed to increase star formation activity dramatically, and most of the brightest starburst galaxies show clear signs of recent interactions. However, it is still not known how interaction triggers star formation, nor are there models to relate the type or strength of interaction to the location or amount of star formation. We report on a series of deep H alpha images of interacting and post-interaction galaxies which we took with the purpose...
Topics: NASA Technical Reports Server (NTRS), GRAVITATIONAL EFFECTS, H ALPHA LINE, INTERACTING GALAXIES,...
During the past year the changeover from the normal incidence X ray telescope (NIXT) program to the new TXI sounding rocket program was completed. The NIXT effort, aimed at evaluating the viability of the remaining portions of the NIXT hardware and design has been finished and the portions of the NIXT which are viable and flightworthy, such as filters, mirror mounting hardware, electronic and telemetry interface systems, are now part of the new rocket payload. The backup NIXT multilayer-coated...
Topics: NASA Technical Reports Server (NTRS), REAL TIME OPERATION, SOUNDING ROCKETS, X RAY TELESCOPES,...
This report provides a description of the NASA Marshall Space Flight Center's Solar Vector Magnetograph Facility and gives a summary of its observations and data reduction during March-May 1994. The systems that make up the facility are a magnetograph telescope, an H-alpha telescope, a Questar telescope, and a computer code.
Topics: NASA Technical Reports Server (NTRS), DATA REDUCTION, MAGNETOMETERS, SOLAR INSTRUMENTS, SOLAR...
The evolution of the EUV and soft X-ray emission in the event on January 19, 1972 are discussed in terms of the slow (passive) and fast (active) phases of flare evolution that were previously discussed. The implications are summarized for a flare build-up model which was derived-from these observations.
Topics: NASA Technical Reports Server (NTRS), OSO-7, SOLAR FLARES, ASTRONOMICAL MODELS, H ALPHA LINE, SOLAR...
The UVSP data obtained in the previous maximum activity cycle show the frequent appearance of flaring events in the UV. In many cases these flaring events are characterized by at least two footpoints which show compact impulsive non-simultaneous brightenings and a fainter but clearly observed arch developes between the footpoints. These arches and footpoints are observed in line corresponding to different temperatures, as Lyman alpha, N V, and C IV, and when observed above the limb display...
Topics: NASA Technical Reports Server (NTRS), BRIGHTNESS TEMPERATURE, SOLAR FLARES, THERMAL ENERGY,...
"Moreton waves," named for the observer who popularized them, are a solar phenomenon also known in scientific literature as "Moreton-Ramsey wave," "flare waves," "flare-associated waves," "MHD blast waves," "chromospheric shock fronts" and various other combinations of terms which connote violently propagating impulsive disturbances. It is unclear whether all of the observations to which these terms have been applied pertain to a...
Topics: NASA Technical Reports Server (NTRS), CHROMOSPHERE, WAVE PROPAGATION, SOLAR FLARES, EMISSION...
Spectrographs of the H-alpha line taken at 15 second intervals from the event of 5 Sept. 1973 were interpreted by comparison with synthetic profiles. A sequence of 27 high resolution H alpha profiles was obtained from the second brightest flare kernel. The profiles were generally self reversed with a maximum peak intensity of 1.16 x continuum and a maximum central intensity of .91 x continuum. The line characteristics such as red and violet peak intensities and positions, center shifts and wing...
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, SOLAR FLARES, SOLAR SPECTRA, SPECTRUM ANALYSIS,...
Observations of the transverse component of the Sun's photospheric magnetic field obtained with the MSFC vector magnetograph show where the fields are nonpotential. The correlation was studied between locations of nonpotential fields and sites of flare onset for four different active regions. The details of the active region AR 4711 are outlined. Similar results are presented for three other regions: AR 2372 (April 1980), AR 2776 (November 1980), and AR 4474 (April 1984). For all four regions...
Topics: NASA Technical Reports Server (NTRS), ENERGY STORAGE, MAGNETIC FIELDS, MAGNETIC SIGNATURES, SHEAR...
Previously, from chromospheric H alpha and coronal X-ray movies of the Sun's polar coronal holes, it was found that nearly all coronal jets (greater than 90%) are one or the other of two roughly equally common different kinds, different in how they erupt: standard jets and blowout jets (Yamauchi et al 2004, Apl, 605, 5ll: Moore et all 2010, Apj, 720, 757). Here, from inspection of SDO/AIA He II 304 A movies of 54 polar x-ray jets observed in Hinode/XRT movies, we report, as Moore et al (2010)...
Topics: NASA Technical Reports Server (NTRS), CORONAL HOLES, DICHOTOMIES, SPACE WEATHER, X RAYS,...
272
272
Jul 23, 2010
07/10
by
Britcher, Colin P
texts
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A preliminary technical assessment of the feasibility of a demonstration Magnetic Levitation system, required to support aerodynamic models with a specified clear air volume around them, is presented. Preliminary calculations of required sizes of electromagnets and power supplies are made, indicating that the system is practical. Other aspects, including model position sensing and controller design, are briefly addressed.
Topics: CONFERENCES, EMISSION SPECTRA, FAR INFRARED RADIATION, H ALPHA LINE, INFRARED ASTRONOMY SATELLITE,...
The scientific goal of UVCS is to obtain detailed empirical descriptions of the extended solar corona as it evolves over the solar cycle and to use these descriptions to identify and understand the physical processes responsible for coronal heating, solar wind acceleration, coronal mass ejections (CMEs), and the phenomena that establish the plasma properties of the solar wind as measured by 'in situ' solar wind instruments. This report covers the period from 01 February 2002 to 15 February...
Topics: NASA Technical Reports Server (NTRS), SOHO MISSION, CORONAGRAPHS, ULTRAVIOLET SPECTROMETERS, SOLAR...
Work proceeded simultaneously in four different areas of solar research. These were: (1) assembly and testing of the components of a multiple-slit H alpha spectrograph, (2) simultaneous observations of the wings of the H alpha line with a newly modified filter, (3) analysis of H alpha high resolution observations in conjunction with magnetic field observations obtained at Kitt Peak, and (4) theoretical analysis of the D3 line HeI.
Topics: NASA Technical Reports Server (NTRS), H ALPHA LINE, HELIUM, SOLAR MAGNETIC FIELD, SPECTROMETERS,...
By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs....
Topics: NASA Technical Reports Server (NTRS), CORONAL HOLES, DICHOTOMIES, MINIATURIZATION, SOLAR CORONA, X...
We present deep ultraviolet (GALEX), radio continuum (VLA) and H-alpha (Magellan) images of the circumgalactic medium around Centaurus A (NGC5128). We focus on the Northern Middle Lobe (NML), a region extending more than 50kpc beyond the galaxy and known to host a collection of striking phenomena: emission line filaments, recent star formation, disrupted HI/molecular gas streams, and short-lived X-ray clouds. Far UV emission is tightly correlated with H-alpha emission for more than 50kpc, and...
Topics: NASA Technical Reports Server (NTRS), STARBURST GALAXIES, RADIO EMISSION, COLD GAS, GAS STREAMS,...
Some results are presented from a continuing investigation of the coronal structure vs. the photospheric magnetic field relationship. Two approaches to the problem are considered. First, the individual coronal features recorded at each limb were located on a chart of the magnetic field measured with low spatial resolution, depicting the large scale or global field configuration. Second, the characteristics of neutral line segments, defined by the presence of H alpha line filament, with no...
Topics: NASA Technical Reports Server (NTRS), BRIGHTNESS DISTRIBUTION, PHOTOSPHERE, SOLAR CORONA, SOLAR...
144
144
May 27, 2011
05/11
by
Hansen, Patricia A.; Hughes, David W.; Montt, Kristina M.; Triolo, Jack J
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Maintaining contamination certification of multi-mission flight hardware is an innovative approach to controlling mission costs. Methods for assessing ground induced degradation between missions have been employed by the Hubble Space Telescope (HST) Project for the multi-mission (servicing) hardware. By maintaining the cleanliness of the hardware between missions, and by controlling the materials added to the hardware during modification and refurbishment both project funding for contamination...
Topics: MAGNETIC FIELDS, SOLAR CONVECTION (ASTRONOMY), ROOT-MEAN-SQUARE ERRORS, AZIMUTH, MAGNETIC...
Galactic and non-galactic components of the diffuse H-alpha and H-beta night sky emissions were resolved with a Fabry-Perot spectrometer. The non-galactic component of both lines accounts for most of the emission at galactic latitudes greater than 30 deg. The intensities of the galactic component yield values for the average ionization rate per hydrogen atom that are between 10 to the minus 15th power and 10 to the minus 14th power s sup minus 1 assuming steady state ionization.
Topics: NASA Technical Reports Server (NTRS), FABRY-PEROT SPECTROMETERS, H ALPHA LINE, H BETA LINE,...
Magnetic shear was observed in several active regions prior to flaring activity. However, certain flares were observed with no apparent shear present. A more detailed investigation of such events is required.
Topics: NASA Technical Reports Server (NTRS), DATA ACQUISITION, MAGNETIC MEASUREMENT, SHEAR FLOW, SOLAR...
This AO-3 observation of a new narrow-line QSO was motivated by our extensive study of the unclassified X-ray sources from the ROSAT/IRAS survey of Boller et al. IRAS 2018.1-2244 was observed to have Balmer lines and forbidden lines of roughly equal width. There are possibly weak broad wings on the H-alpha line. One of the questions to be addressed by hard X-ray spectroscopy is whether or not these wings are to be interpreted as scattered or weakly transmitted flux from a hidden broad-line...
Topics: NASA Technical Reports Server (NTRS), X RAY SOURCES, QUASARS, PULSARS, SEYFERT GALAXIES, EMISSION...
The Principal Investigator (P.I.) has been pursuing a three year grant under NASA's Sun-Earth Connection Guest Investigator Program in support of the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). An objective of these efforts is to combine X-ray and other data on solar flares, coronal mass ejections and interplanetary particle events in order to obtain a more comprehensive recognition of signatures, and understanding of interplanetary proton events. Thus, part of these efforts are to...
Topics: NASA Technical Reports Server (NTRS), CORONAL MASS EJECTION, SOLAR FLARES, SPECTROSCOPY, X RAY...
The UV spectra of three Be stars (gamma Cas, sigma Tau, eta Cen) were studied. Of the six Be stars observed in the first four lines of the Balmer series, three stars showed at least one of the Balmer lines to be variable in the equivalent width amounting to a few percent with time scales of 3 to 30 minutes. Photoelectric spectrum scans of five southern Wolf-Rayet stars showed night-to-night variations. A simple model is proposed to account for the behavior of these emission lines. Scans of...
Topics: NASA Technical Reports Server (NTRS), EMISSION SPECTRA, LINE SPECTRA, STELLAR SPECTRA, ULTRAVIOLET...
The impulsive phase of a flare is characterized by impulsive bursts of X-ray and microwave radiation, related to impulsive footpoint heating up to 50 or 60 MK, by upward gas velocities (150 to 400 km/sec) and by a gradual increase of the flare's thermal energy content. These phenomena, as well as non-thermal effects, are all related to the impulsive energy injection into the flare. The available observations are also quantitatively consistent with a model in which energy is injected into the...
Topics: NASA Technical Reports Server (NTRS), ELECTRONS, ENERGETIC PARTICLES, IMPULSES, PHOTOSPHERE, SOLAR...
