Measurements of Solar Radiation at a Wavelength of 50 Centimetres during the Eclipse of November 1, 1948

1949 ◽  
Vol 2 (4) ◽  
pp. 506 ◽  
Author(s):  
WN Christiansen ◽  
DE Yabsley ◽  
BY Mills
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Total Power ◽  
The Sun ◽  
Radio Brightness ◽  
Circularly Polarized ◽  
Small Areas ◽  
Abrupt Changes ◽  
Frequency Power ◽  
Visible Disk

Radio-frequency power received from the sun at a wavelength of 50 cm. was measured at three well-separated places during the solar eclipse of November 1, 1948. Abrupt changes in slope on the records of received flux density were interpreted as being the result of the covering and uncovering on the sun of small areas of great radio brightness. These areas were found to be associated with some visible sunspots, with positions previously occupied by sunspots, and with one prominence. The average effective temperature of the bright areas was about 5 X 106 �K., and the are= contributed a total power of roughly one-fifth of that from the entire sun. After the effects of active areas had been taken into account, the remaining four- fifths of the power received from the sun was found to originate from a source larger than the visible disk. About 40 per cent. of the power from this source originated outside the edge of the visible disk. The results were consistent with a theoretical distribution of brightness on the source, which involved limb-brightening. The relative magnitudes of the two circularly-polarized components of the solar radiation showed small differences as the bright areas were eclipsed. No predominance of one component was seen when one hemisphere of the sun was eclipsed ; hence no effects of any general magnetic field on the sun were detected.

scholarly journals 42. Solar cosmic radiation and the interstellar magnetic field

1958 ◽  
Vol 6 ◽  
pp. 404-419 ◽  
Author(s):  
A. Ehmert
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Cosmic Radiation ◽  
The Sun ◽  
High Latitudes ◽  
Narrow Angle ◽  
The Earth ◽  
Order Of Magnitude ◽  
The Impact ◽  
Impact Zones

The increase of cosmic radiation on 23 February 1956 by solar radiation exhibited in the first minutes a high peak at European stations that were lying in direct impact zones for particles coming from a narrow angle near the sun, whilst other stations received no radiation for a further time of 10 minutes and more. An hour later all stations in intermediate and high latitudes recorded solar radiation in a distribution as would be expected if this radiation fell into the geomagnetic field in a fairly isotropic distribution. The intensity of the solar component decreased at this time at all stations according to the same hyperbolic law (~t–2).It is shown, that this decreasing law, as well as the increase of the impact zones on the earth, can be understood as the consequence of an interstellar magnetic field in which the particles were running and bent after their ejection from the sun.Considering the bending in the earth's magnetic field, one can estimate the direction of this field from the times of the very beginning of the increase in Japan and at high latitudes. The lines of magnetic force come to the earth from a point with astronomical co-ordinates near 12·00, 30° N. This implies that within the low accuracy they have the direction of the galactic spiral arm in which we live. The field strength comes out to be about 0·7 × 10–6gauss. There is a close agreement with the field, that Fermi and Chandrasekhar have derived from Hiltner's measurements of the polarization of starlight and the strength of which they had estimated to the same order of magnitude.

Solar Radiation at 1200 MC/S., 600 MC/S., and 200 MC/S

1949 ◽  
Vol 2 (1) ◽  
pp. 48 ◽  
Author(s):  
FJ Lehany ◽  
DE Yabsley
Keyword(s):  
Magnetic Field ◽  
Body Temperature ◽  
Solar Radiation ◽  
Thermal Emission ◽  
Black Body ◽  
Sunspot Area ◽  
The Sun ◽  
Long Period ◽  
Period Variations ◽  
The Magnetic Field

Daily observations of solar radiation at frequencies of 1200 Mc/s., 600 Mc/s., and 200 Mc/s. taken between August 18 and November 30, 1947, are described. The characteristics of the radiation at 200 Mc/s. were in general agreement with those observed by earlier workers. At 600 Mc/s. and 1200 Mc/s., the received intensity was normally steady on any one day but underwent long-period variations over a range of about two to one. The radiation received when the sun was almost free of sunspots corresponded to an effective black-body temperature of 0.5 million �K. at 600 Mc/s. and 0.1 million �K. at 1200 Mc/s. As sunspots appeared, the temperature rose and showed marked oar- relation with sunspot area. It is considered that radiation at these frequencies is entirely thermal in origin and that the long-period variations are at least partly due to the influence of the magnetic field of sunspots on the mechanism of thermal emission from a magneto-ionic medium. On a few occasions, isolated disturbances were observed on 600 Mc/s. and 1200 Mc/s. some of which were associated with chromospheric flares and radio fade-outs. The difficulties arising in the calibration of the apparatus and the steps taken to overcome them are discussed in detail.

Solar Radio Observations at 843 MHz

1989 ◽  
Vol 8 (2) ◽  
pp. 142-144 ◽  
Author(s):  
A. D. Gray ◽  
D. Campbell-Wilson ◽  
M. I. Large
Keyword(s):  
Solar Radio ◽  
Coronal Holes ◽  
Total Power ◽  
The Sun ◽  
Two Dimensional ◽  
Radio Observations ◽  
Radio Brightness ◽  
Partial Synthesis ◽  
One Dimensional ◽  
Exact Relationship

AbstractThe Molonglo Observatory Synthesis Telescope (MOST) has been used to observe the Sun with total-power fan-beams having a one-dimensional resolution of 41 arcsec at 843 MHz. The scans reveal clearly the rotation and evolution of the slowly-varying component as well as some burst activity. Low radio brightness features have also been identified, but the exact relationship between these features and coronal holes is, as yet, unclear. Several partial synthesis observations have been used to generate two-dimensional radioheliograms.

scholarly journals The Distribution of Radio Brightness Over the Solar Disk at a Wavelength of 21 Centimetres. IV. The Slowly Varying Component

1957 ◽  
Vol 10 (4) ◽  
pp. 491 ◽  
Author(s):  
WN Christiansen ◽  
JA Warburton ◽  
RD Davies
Keyword(s):  
Solar Radiation ◽  
Solar Disk ◽  
The Sun ◽  
Radio Brightness

A large number of highly emitting regions on the Sun have been studied individually by means of a 32-element interferometer which produces fringes 3 min of arc wide at a wavelength of 21 cm. These regions are responsible for the slowly varying component of the solar radiation at decimetre wavelengths.

Solar Radiation at a Wavelength of 3.18 Centimetres

1950 ◽  
Vol 3 (1) ◽  
pp. 60 ◽  
Author(s):  
HC Minnett ◽  
NR Labrum
Keyword(s):  
Body Temperature ◽  
Solar Radiation ◽  
Black Body ◽  
Sunspot Area ◽  
Probable Error ◽  
The Sun ◽  
Solar Origin ◽  
Unit Increase ◽  
Uniform Disk ◽  
Visible Disk

Solar radiation at a wavelength of 3.18 cm. has been measured over a period of three months. The received intensity was found to vary from day to day and the changes are shown to be closely associated with sunspots. The equivalent black-body temperature of the sun over this period, in the absence of sunspots, was 19,300 �K., with a probable error of �7 per cent. The temperature increased by 8 �K. per unit increase of sunspot area (one unit equals 10-5 times the area of the sun's visible disk). This increase is much less than that at longer microwavelengths. Sudden increases of radiation at 3.18 cm., caused by disturbed conditions in the sun, were found to be rare. A number of bursts were observed and a comparison is made with records of longer wave solar radiation and other phenomena of solar origin. Observations were made during the solar eclipse of November 1, 1948 and the results are consistent with either of two simple brightness distributions on the sun's disk. In the first of these, 74 per cent. of the energy is emitted uniformly by the sun's visible disk and the remaining 26 per cent. by a bright ring around the circumference ; in the second, the whole of the radiation comes from a uniform disk of diameter 1.1 times that of the visible sun.

scholarly journals ANALISIS INTENSITAS RADIASI MEDAN MAGNET MATAHARI

2021 ◽  
Vol 7 (1) ◽  
pp. 169
Author(s):  
Sudarti Sudarti ◽  
Sherly Nur Laili
Keyword(s):  
Magnetic Field ◽  
Solar Radiation ◽  
Radiation Intensity ◽  
Low Frequency ◽  
Wave Radiation ◽  
The Sun ◽  
Extremely Low Frequency ◽  
Field Radiation ◽  
C 32 ◽  
The Magnetic Field

ABSTRAKMedan magnet ELF (Extremely Low Frequency) merupakan spektrum gelombang elektromagnetik yang frekuensinya 0-300 Hz. Matahari sumber kehidupan yang memancarkan energinya ke bumi dalam bentuk radiasi gelombang elektromagnetik. Penelitian ini bertujuan untuk membandingkan intensitas radiasi medan magnet alamiah matahari didalam ruangan dan diluar ruangan. Jenis penelitian yang digunakan adalah penelitian eksperimen. Pengukuran intensitas radiasi medan magnet oleh matahari menggunakan alat Electromagnetic Field (EMF) Meter dan thermometer. Penelitian dilakukan mulai pukul 06.00 – 15.00 WIB dimana semakin siang temperatur medan magnet dan radiasi matahari semakin meningkat, kemudian suhu dan intensitas menurun seiring dengan terbenamnya matahari. Teknik analisa data yang digunakan menggunakan SPSS dengan metode interpretasi data. Hasil Penelitian menunjukkan data diluar ruangan memiliki hasil lebih tinggi dibandingkan dengan data hasil penelitian di dalam ruangan yakni rerata suhu didalam ruangan 29,5˚C, 31˚C, 32,36˚C,dan 31,7˚C sedangkan diluar ruangan 30,9˚C, 32,9˚C, 33,4˚C, 32˚C. Rerata medan magnet didalam ruangan sebesar 0,044, 0,224, 0,262, dan 0,326, sedangkan diluar ruangan sebesar 0,098, 0,324, 0,418, dan 0,398.  Data penelitian menunjukkan bahwa semakin tinggi intensitas radiasi matahari mengakibatkan temperatur bumi, dan medan magnet semakin tinggi. Kata kunci: intensitas;matahari; medan magnet;radiasi. ABSTRACTElf magnetic field (Extremely Low Frequency) is a spectrum of electromagnetic waves whose frequency is 0-300 Hz. Sun is a source of life that emits its energy to earth in the form of electromagnetic wave radiation. This study aims to compare the radiation intensity of natural magnetic fields by the sun indoors and outdoors. The type of research used is experimental research. Measurement of magnetic field radiation intensity by the sun using EMF Meter and thermometer. The research was conducted from 06.00 – 15.00 WIB where the more daylight the temperature of the magnetic field and solar radiation increases, then the temperature and intensity decreases with the sunset. Data analysis techniques used using SPSS with data interpretation methods. The results showed that outdoor data had higher results compared to the data of indoor research results, namely the average indoor temperature of 29.5°C, 31°C, 32.36°C, and 31.7°C while outdoors 30.9°C, 32.9°C, 33.4°C, 32°C. The average indoor magnetic field is 0.044, 0.224, 0.262, and 0.326, while outdoors is 0.098, 0.324, 0.418, and 0.398.  Research data shows that the higher the intensity of solar radiation results in the Earth's temperature, and the magnetic field gets higher. Keywords: intensity;sun; magnetic field;radiation.

Emergence of Twisted Magnetic Flux Related Sigmoidal Brightening

2000 ◽  
Vol 179 ◽  
pp. 263-264
Author(s):  
K. Sundara Raman ◽  
K. B. Ramesh ◽  
R. Selvendran ◽  
P. S. M. Aleem ◽  
K. M. Hiremath
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Ultra Violet ◽  
Active Regions ◽  
Morphological Properties ◽  
Energy Storage And Conversion ◽  
The Sun ◽  
X Rays ◽  
The Magnetic Field

Extended AbstractWe have examined the morphological properties of a sigmoid associated with an SXR (soft X-ray) flare. The sigmoid is cospatial with the EUV (extreme ultra violet) images and in the optical part lies along an S-shaped Hαfilament. The photoheliogram shows flux emergence within an existingδtype sunspot which has caused the rotation of the umbrae giving rise to the sigmoidal brightening.It is now widely accepted that flares derive their energy from the magnetic fields of the active regions and coronal levels are considered to be the flare sites. But still a satisfactory understanding of the flare processes has not been achieved because of the difficulties encountered to predict and estimate the probability of flare eruptions. The convection flows and vortices below the photosphere transport and concentrate magnetic field, which subsequently appear as active regions in the photosphere (Rust & Kumar 1994 and the references therein). Successive emergence of magnetic flux, twist the field, creating flare productive magnetic shear and has been studied by many authors (Sundara Ramanet al.1998 and the references therein). Hence, it is considered that the flare is powered by the energy stored in the twisted magnetic flux tubes (Kurokawa 1996 and the references therein). Rust & Kumar (1996) named the S-shaped bright coronal loops that appear in soft X-rays as ‘Sigmoids’ and concluded that this S-shaped distortion is due to the twist developed in the magnetic field lines. These transient sigmoidal features tell a great deal about unstable coronal magnetic fields, as these regions are more likely to be eruptive (Canfieldet al.1999). As the magnetic fields of the active regions are deep rooted in the Sun, the twist developed in the subphotospheric flux tube penetrates the photosphere and extends in to the corona. Thus, it is essentially favourable for the subphotospheric twist to unwind the twist and transmit it through the photosphere to the corona. Therefore, it becomes essential to make complete observational descriptions of a flare from the magnetic field changes that are taking place in different atmospheric levels of the Sun, to pin down the energy storage and conversion process that trigger the flare phenomena.

Polar Magnetic Field Reversals of the Sun in Maunder Minimum

2000 ◽  
Vol 179 ◽  
pp. 193-196
Author(s):  
V. I. Makarov ◽  
A. G. Tlatov
Keyword(s):  
Magnetic Field ◽  
Maunder Minimum ◽  
The Sun ◽  
Annual Rings ◽  
Field Reversal ◽  
Polar Magnetic Field ◽  
Pine Trees ◽  
Using Data ◽  
Magnetic Field Reversal

AbstractA possible scenario of polar magnetic field reversal of the Sun during the Maunder Minimum (1645–1715) is discussed using data of magnetic field reversals of the Sun for 1880–1991 and the14Ccontent variations in the bi-annual rings of the pine-trees in 1600–1730 yrs.

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