共查询到20条相似文献,搜索用时 93 毫秒
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Yngve Öhman 《Solar physics》1969,10(1):178-183
During a stay at the Kitt Peak National Observatory the writer has tried to find an influence of flare radiation on the high photospheric and low chromospheric lines of the area occupied by the flare. Observations have been made in the H region and in the region of the H and K lines. When flare emission is present in sunspots some of the faint (molecular) lines seem to be weakened. When a flare appears near the solar limb some of the Evershed-type (chromospheric) lines are strongly influenced.Kitt Peak National Observatory Contribution No. 481.Visiting Astronomer to the Solar Division, Kitt Peak National Observatory, operated by the Association of Universities for Research in Astronomy, Inc. under contract with the National Science Foundation. 相似文献
3.
Yngve Öhman 《Solar physics》1969,9(2):427-431
The writer reports some recent observations carried out with the McMath Solar Telescope, which can be interpreted as due to
rotational motions in prominences.
Kitt Peak National Observatory Contribution No. 454.
Visiting Astronomer to the Solar Division, Kitt Peak National Observatory, operated by the Association of Universities for
Research in Astronomy, Inc. under contract with the National Science Foundation. 相似文献
4.
V. Bumba 《Solar physics》1967,1(3-4):371-376
Preliminary results of magnetic field measurements in small sunspots from spectrograms obtained with the aid of the McMath Solar Telescope at the Kitt Peak National Observatory are presented. The measured intensities are greater than or equal to about 1200 Gauss. Furthermore, a broadening of the Fei line 6302.508 Å was found in some places of intergranular space. The importance of intergranular space as a possible potential earliest stage of sunspot development is mentioned.Kitt Peak National Observatory, Contribution No. 222.Visiting Astronomer, 1964, Kitt Peak National Observatory.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the Nat. Science Foundation. 相似文献
5.
The design, construction and use of a multi-purpose photometer is discussed. It is intended to work between 9000 Å to 3700 Å on the 25-inch Turner-Newall refractor of the Athens National Observatory and eventually on the Greek 48-inch reflector now under construction. 相似文献
6.
H. Tanaka J. P. Castelli A. E. Covington A. Krüger T. L. Landecker A. Tlamicha 《Solar physics》1973,29(1):243-262
The absolute calibration of solar radio flux density in the microwave region, which showed considerable discrepancies until 1966, has become completely uniform through international cooperative work. A complete history is described to avoid confusion, and correction factors are derived to convert the published values into absolute values for long series of routine observations. It is also shown that the most reliable calibration can be made by using a large pyramidal horn and by using sky and room temperature as calibration standards.Abbreviation of Stations for Table II, Figures 2 and 3 BERL
Heinrich-Hertz-Institut, Berlin Adlershof
- BORD
The Observatory, the University of Bordeaux
- GORK
Radiophysical Research Institute, Gorky
- HIRA
Hiraiso Radio Observatory
- HUAN
Geophysical Institute of Peru, Huancayo
- IRKU
Irkutsk Radioastronomical Observatory
- KIEL
Radio Observatory, Kiel University
- Radio
Observatory, Kiel University
- KSLV
Kislovodsk Radioastronomical Observatory
- MANI
Manila Observatory
- ONDR
Ondejov Observatory
- OTTA
National Research Council, Ottawa
- PENT
Dominion Radioastronomical Observatory, Penticton
- SANM
Observatory of Cosmic Physics, San Miguel
- SAOP
Mackenzie University, Sao Paulo
- SGMR
Sagamore Hill Radio Observatory
- SYDN
University of Sydney
- TOKO
Tokyo Astronomical Observatory
- TYKW
Toyokawa Observatory, Nagoya University
- UCCL
Belgian Royal Observatory, Uccle 相似文献
7.
Arch-like features are often seen in spectrograms of very strong lines near the solar limb when the slit crosses the chromospheric network. We show how earlier kinetic-equilibrium (non-LTE) calculations for Ca ii can be used to predict such features for the K line with two-component atmospheric models.Publication of the Goethe Link Observatory, Indiana University, No. 144Now on leave at the High Altitude Observatory, National Center for Atmospheric Research, Boulder, Colorado. (NCAR is sponsored by the National Science Foundation.) 相似文献
8.
J. C. Christou 《Experimental Astronomy》1991,2(1):27-56
The extended Knox-Thompson reduction scheme currently in use at Kitt Peak National Observatory and Steward Observatory for the reduction of infrared speckle interferometry is described in detail. Applications of this algorithm and the less computationally intensive shift-and-add analysis to both simulated and real binary star data is presented demonstrating that the latter may be successfully used for image reconstruction by using a separately measured point source. The performance of both techniques is shown to improve by application of an iterative deconvolution algorithm to apply a priori image constraints without degradation of photometric information.Operated by the Association of Universities for Research in Astronomy Inc. (AURA) under cooperative agreement with the National Science Foundation 相似文献
9.
Observations of a limb flare and an associated loop prominence were obtained in H with the 512 channel magnetograph of the Kitt Peak National Observatory. Simultaneous radial and torsional oscillations with a period near 75 s, wavelength of 37 000 km, and amplitude of 1–2 km s–1 were detected in the loop approximately 90 min before the onset of the flare. We interpret these coupled oscillations in terms of a kink instability of a current carrying flux tube. The magnitude of the steady-state component of current is estimated to be 6 × 1010 ampères.Visiting Astronomer, Kitt Peak National Observatory, operated by Aura, Inc., under contract with the National Science Foundation.Visiting Student, Kitt Peak National Observatory. 相似文献
10.
J. Y. Hu 《Astrophysics and Space Science》1994,217(1-2):53-54
A high spatial resolution near infrared imaging system is being developed at Beijing Observatory. It is a joint-project with Institute of Optics and Electronics, CSA, and National Astronomical Observatory, Japan. The system contains a 512 × 512 PtSi CSD near infrared camera and a 21-element adaptive optics system and will be operated at Coudé focus of the 2.16 meter telescope at Xinglong Station, Beijing Observatory. The infrared camera will be fixed at Cassegrain focus with focus reducers too. 相似文献
11.
Double pass photoelectric observations are presented of five Caii lines (H, K, 8498 Å, 8542 Å, and 8662 Å) in a number of solar plages of different degrees of activity, quiet regions, and a sunspot. The data are compared with previous work. All five lines show increasing emission together in plages and the least opaque of the infrared triplet lines appears to exhibit core emission prior to the more opaque members of the multiplet. The question of source function equality is considered and the differences and similarities among plage profiles and between plage and quiet profiles are shown qualitatively and quantitatively.Staff Member, Laboratory Astrophysics Division, National Bureau of Standards.Visiting Astronomer at Kitt Peak National Observatory, which is operated by the Association of Universities for Research in Astronomy. Inc., under contract with the National Science Foundation. 相似文献
12.
Observations are presented which suggest that away from sunspots photospheric magnetic flux is quantized. Assuming the elemental area of a magnetic region to be 1 (arc-sec)2 the elemental field strength is 525 G.Kitt Peak National Observatory Contribution No. 501.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. 相似文献
13.
The linear polarization of the reflection nebula R Mon/NGC 2261 has been observed since November 1991 with a multi-channel polarimeter at Dodaira Observatory, one of the branches of the National Astronomical Observatory of Japan. Results of the observations are reported. 相似文献
14.
Using H observations made at the Astronomical Observatory of Wroclaw University, and 3.5–5.5 keV X-ray data from the Hard X-ray Imaging Spectrometer on board the Solar Maximum Mission, sites of solar X-ray emission are identified which are associated with active H features, such as prominences, sprays and surges. The X-ray emission is found to be highly localized within the active (H) structures. For example, in the prominences examined, 3.5–5.5 keV X-rays were found only in compact sites near the feet of the prominences. Models predicting that, during the active phase of these structures, the energy release should be evenly distributed along the structure are clearly brought into question. It is argued that these X-ray sites are indicative of the cause of the expulsion and transport of chromospheric material. Models which satisfy these observations are discussed.This work was started during a visit to the High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307, U.S.A. (NCAR is sponsored by the National Science Foundation). 相似文献
15.
Harrison P. Jones Thomas L. Duvall Jr. John W. Harvey Charles T. Mahaffey Jan D. Schwitters Jorge E. Simmons 《Solar physics》1992,139(2):211-232
The NASA/NSO Spectromagnetograph is a new focal plane instrument for the National Solar Observatory/Kitt Peak Vacuum Telescope which features real-time digital analysis of long-slit spectra formed on a two-dimensional CCD detector. The instrument is placed at an exit port of a Littrow spectrograph and uses an existing modulator of circular polarization. The new instrument replaces the 512-channel Diode Array Magnetograph first used in 1973. Commercial video processing boards are used to digitize the spectral images at video rates and to separate, accumulate, and buffer the spectra in the two polarization states. An attached processor removes fixed-pattern bias and gain from the spectra in cadence with spatial scanning of the image across the entrance slit. The data control computer performs position and width analysis of the line profiles as they are acquired and records line-of-sight magnetic field, Doppler shift, and other computed parameters. The observer controls the instrument through windowed processes on a data control console using a keyboard and mouse. Early observations made with the spectromagnetograph are presented and plans for future development are discussed.The National Solar Observatory is a Division of the National Optical Astronomy Observatories which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. 相似文献
16.
E. Landi Degl'Innocenti 《Solar physics》1979,63(2):237-245
Linearly polarized intensity distributions observed in sunspots with the Marshall Space Flight Center's (MSFC) vector magnetograph are interpreted taking into account magneto-optical effects. It is shown that these effects can be responsible for the observed spiral configuration in the pattern of linear polarization, even if a purely radial, conventional sunspot model is used.On leave from: Astrophysical Observatory of Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy.The National Center for Atmospheric Research is sponsored by the National Science Foundation. 相似文献
17.
We analyze the vector magnetograms in several well-developed active regions obtained at Huairou Solar Observing Station, National Astronomical Observatories of China, at Mees Solar Observatory, University of Hawaii, and at National Astronomical Observatory of Japan. It is found that there is a basic agreement on the transversal fields among these magnetographs. The observational error (mutual difference) for the transversal magnetic fields is estimated. In addition to comparison of transversal fields among different instruments, we used the morphological configurations of sunspot penumbrae in white-light and EUV 171 Å images obtained by the TRACE satellite as a reference of the orientation of transversal magnetic fields. 相似文献
18.
Edward G. Schmidt Jeffrey D. Rosendhal C. P. Jewsbury 《Astrophysics and Space Science》1974,29(2):397-414
Line strengths are presented for 15 yellow supergiants and 6 Cepheids. These line strengths are compared with those obtained
previously by other investigators.
Visiting Astronomer, Kitt Peak National Observatory, which is operated by the Association of Universities for Research in
Astronomy, Inc., under contract with the National Science Foundation. 相似文献
19.
Egidio Landi Degl'innocenti 《Solar physics》1982,79(2):291-322
A method is presented to measure the magnetic field vector in prominences by means of the polarimetric observations in the D3 line of He obtained with the High Altitude Observatory Stokes polarimeter. The characteristics of the observed Stokes profiles are discussed. The theory of the Hanle effect is reformulated in the representation of the irreducible tensors of the density matrix, and is generalized to derive the circular polarization profiles across the spectral line in terms of the intensity and direction of the prominence magnetic field. The circular polarization profile so deduced can be employed to obtain useful information which adds to that carried by the linear polarization observations. A non-linear least-squares algorithm is proposed to derive the measurement of the magnetic field from the observations, and a consistency check is suggested to test the adequacy of the theoretical model to describe the physics of the He I atomic excitation in prominences.On leave from: Astrophysical Observatory of Arcetri, Largo E. Fermi, 5, 50125 Firenze, Italy.The National Center for Atmospheric Research is sponsored by the National Science Foundation. 相似文献
20.
Hector Socas-Navarro David Elmore Anna Pietarila Anthony Darnell Bruce W. Lites Steven Tomczyk Steven Hegwer 《Solar physics》2006,235(1-2):55-73
The Spectro-Polarimeter for Infrared and Optical Regions (SPINOR) is a new spectro-polarimeter that will serve as a facility
instrument for the Dunn Solar Telescope at the National Solar Observatory. This instrument is capable of achromatic polarimetry
over a very broad range of wavelengths, from 430 to 1600 nm, allowing for the simultaneous observation of several visible
and infrared spectral regions with full Stokes polarimetry. Another key feature of the design is its flexibility to observe
virtually any combination of spectral lines, limited only by practical considerations (e.g., the number of detectors available, space on the optical bench, etc.).
Visiting Astronomers, National Solar Observatory, operated by the Association of Universities for Research in Astronomy, Inc.
(AURA), under cooperative agreement with the National Science Foundation. 相似文献