Plant diseases can be infectious (transmitted from plant to plant) or noninfectious. Noninfectious diseases are usually referred to as disorders. Common plant disorders are caused by deficiencies in plant nutrients, by waterlogged or polluted soil, and by polluted air.
Such refinements in the images of Betelgeuse's atmosphere has been helping to resolve the mystery of how massive amounts of dust and gas are expelled from red supergiant stars, an important source of enrichment for the interstellar medium.
Find the radius of the star Rigel, the bright blue star in the constellation Orion that radiates energy at a rate of 2.7 x 10^32 W and has a surface temperature of 11,000 K. Assume that the star is spherical. Use Ï =... show more It is a good approximation to assume that the emissivity e is equal to 1 for these surfaces.