Search results
Results From The WOW.Com Content Network
Albedo (/ æ l ˈ b iː d oʊ / al-BEE-doh; from Latin albedo 'whiteness') is the fraction of sunlight that is diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects all incident radiation).
The darkest ones are related to the C-group, with an albedo below 0.1. These are the "primitive" P-type ( 259 Aletheia , 190 Ismene ), which differ from the "metallic" M-type ( 16 Psyche ) with an intermediate albedo of 0.10 to 0.30, and from the bright "enstatite" E-type asteroid , mostly seen among the members of the Hungaria family in the ...
For the maximum estimated diameter (137 km), the minimum albedo of the nucleus would be 3.3% ± 0.9%. [9] C/2014 UN 271 's low albedo is characteristic of small comet nuclei from both short- and long-period populations, suggesting a lack of correlation between albedo, nucleus size, and orbit type in Solar System comets. [10]
At last quarter, the Moon is about 0.06 mag fainter than at first quarter, because that part of its surface has a lower albedo. Earth's albedo varies by a factor of 6, from 0.12 in the cloud-free case to 0.76 in the case of altostratus cloud. The absolute magnitude in the table corresponds to an albedo of 0.434.
This implies that a star of magnitude m is about 2.512 times as bright as a star of magnitude m + 1. This figure, the fifth root of 100 , became known as Pogson's Ratio. [ 9 ] The 1884 Harvard Photometry and 1886 Potsdamer Duchmusterung star catalogs popularized Pogson's ratio, and eventually it became a de facto standard in modern astronomy to ...
In a close binary star system polarimetry can be used to measure the light reflected from one star off another (and vice versa) and therefore also the geometric albedos of the two stars. This task has been accomplished for the two components of the Spica system, with the geometric albedo of Spica A and B being measured as 0.0361 and 0.0136 ...
The first important result from the Kepler Mission about TrES-2b is an extremely low geometric albedo measured in 2011, making it the darkest known exoplanet. [5] If the entire day–night contrast were due to geometric albedo, it would be 2.53%, but modeling suggests that much of this is dayside emission and the true albedo is much lower. It ...
A-type star In the Harvard spectral classification system, a class of main-sequence star having spectra dominated by Balmer absorption lines of hydrogen. Stars of spectral class A are typically blue-white or white in color, measure between 1.4 and 2.1 times the mass of the Sun, and have surface temperatures of 7,600–10,000 kelvin.