A pastel halo around the moon or sun created by the diffraction of water droplets The droplets in the cloud, such as cirrostratus, and the cloud layer itself must be almost perfectly uniform in order for this phenomena to occur The color display sometimes appears to be iridescent
A peculiar phase of the aurora borealis, formed by the concentration or convergence of luminous beams around the point in the heavens indicated by the direction of the dipping needle
1) The upper level of the solar atmosphere, characterized by low densities and high temperatures (> 1 0E+06 K); it is not visible from the Earth except during a total eclipse of the sun or by use of special telescopes called coronagraphs 2) An ovoid-shaped feature
1) The upper level of the solar atmosphere, characterized by low densities and high temperatures (> 1 0E+06 K); it is not visible from the Earth except during a total eclipse of the sun or by use of special telescopes called coronagraphs 2) An ovoid-shaped feature
The atmosphere of the Sun that can be observed out to many times the size of the Sun's main surface, which is called the photosphere The corona is much hotter than the photosphere, but it has a much lower density The gases in the corona are electrically charged Warning: The Sun should be observed only with special equipment to protect the eyes
the outermost layer of the Sun's atmosphere, visible to the eye during a total solar eclipse; it can also be observed through special filters and best of all, by X-ray cameras aboart satellites The corona is very hot, up to 1-1 5 million degrees centigrade, and is the source of the solar wind
The sun's corona is its outer atmosphere. the shining circle of light seen around the sun when the moon passes in front of it in an eclipse (CROWN). Outermost region of the Sun's (or any star's) atmosphere, consisting of plasma. The Sun's corona has a temperature of about 3.6 million °F (2 million °C) and a very low density. Extending more than 8 million mi (13 million km) from the photosphere, it has no definite boundaries, continually varying in size and shape as it is affected by the Sun's magnetic field. The solar wind is formed by expansion of coronal gases. Only about half as bright as the full moon, the corona is overwhelmed by the brilliance of the solar surface and normally not visible to the unaided eye, but a total eclipse permits naked-eye observations
The outermost layer of the solar atmosphere The corona consists of a highly rarefied gas with a temperature greater than one million degrees Kelvin It is visible to the naked eye during a solar eclipse
a sonnet sequence where the last line in one sonnet becomes the first line of the next sonnet, and the final line in the sequence repeats the first line of the first sonnet An example is the seven sonnets that open John Donne's holy sonnets
The very hot outer layer of the Sun's atmosphere, composed of highly diffused, superheated, ionized gases, and extending into interplanetary space The hot gasses in the solar corona form the solar wind See also: The Dynamic Sun
A luminous discharge due to ionization of the gas surrounding a conductor around which exists a voltage gradient exceeding a certain critical value A type of discharge-sometimes visible-in the dielectric of an insulation system caused by an electric field and characterized by the rapid development of an ionized channel which does not completely bridge the electrode May be continuous or intermittent Not a material property, but related to the system, including electrodes
corona = [Latin] from koroone = [Greek] crown The corona is the outermost layer of the Sun, starting at about 1300 miles (2100 km) above the surface (the photosphere) The temperature in the corona is 500,000 K (900,000 degrees F, 500,000 degrees C) or more, up to a few million K The corona is very dilute indeed (less than 1000 million atoms per cubic centimetre or 10,000 million atoms per cubic inch) and cannot be seen with the naked eye except during a total solar eclipse, or with the use of a coronagraph The corona does not have an upper limit: you could say that the Earth moves through the solar corona, though the density of the material near the Earth is usually only a paltry few particles per cubic centimeter You can see the position of the corona in the Solar Layer Image, and an image of the corona in the Corona Image Map
The outermost layer of the solar atmosphere, characterized by low densities (1 0E+06 degrees K) that extends to several solar radii The heating of the corona is still a mystery The shape of the corona is different at solar maximum and at solar minimum
The outermost layer of the solar atmosphere, characterized by low densities (10E+6 K) It is not visible from the Earth except during a total eclipse of the Sun or by use of a special telescope called a coronagraph
the top layer of the Sun's atmosphere It is up to a few million degrees in temperature, but has very low density so the amount of heat is small It is the pearly-white ``crown'' or glow seen around the dark Moon during a total solar eclipse
The ghostly white halo that surrounds the sun during totality This is the sun's outer atmosphere which is so dim that it can only ever be seen during totality
The tenuous outer atmosphere of the Sun whose structure is controlled by solar magnetic fields The corona has a temperature between 1 and 3 million degrees It merges into the solar wind at its upper boundary about 1-2 solar radii above the visible surface or photosphere
The outer part of the Sun's atmosphere The corona is visible from Earth during a total solar eclipse It is the bright glow seen in most solar eclipse photos
a long cigar with blunt ends (anatomy) any structure that resembles a crown in shape one or more circles of light seen around a luminous object (botany) the trumpet shaped or cup shaped outgrowth of the corolla of a daffodil or narcissus flower
-An electrical discharge at the surface of a conductor accompanied by the ionization of the surronding atmosphere It is normally accompanied by light and audible noise
An electrical discharge characterized by a corona and occurring when one of two electrodes in a gas has a shape causing the electric field at its surface to be significantly greater than that between the electrodes
Corona can be defined as a type of localized discharge that results from high, non-uniform electric fields It causes deterioration of the insulator and sometimes causes complete breakdown A corona discharge is capable of producing oxides of nitrogen, which are pollutants, and generates electromagnetic radiation that may disturb radio and TV reception The obvious ways to detect a corona are by sight and sound At high voltages, corona produces visible light and audible noise Corona can also be detected by using various types of measuring equipment When observed, corona may appear as a faint glow (The AirSource® 3000 model does NOT use corona discharge Rather, it uses an ultraviolet lamp to produce light energy as a photocatalyst While powerful enough to create the advanced oxidation process, the UV lamp does not create oxides of nitrogen that can be irritating to the lungs and eyes )