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51.
Five narrowband interference filters centered at wavelengths 0.365, 0.387, 0.406, 0.484, and 0.514 μm have been selected by the International Astronomical Union to represent ultraviolet continuum, CN emission, C3 emission, blue continuum, and C2 emission in the spectra of comets, respectively. We present adopted magnitudes and colors in this filter system for 50 standard stars ranging in blue magnitude 4 to 12, in spectral type from O to K, and mostly distributed around equatorial regions of the sky. Tabulated uncertainties are generally on the order of 0.02 mag or smaller. The zero points of the photometric system are chosen such that blue-continuum magnitudes are approximately equivalent to Johnson B, and such that color indices average zero for solar analog stars. 相似文献
52.
Ben Zellner 《Icarus》1976,28(1):149-153
Newly available photometric, polarimetric, spectroscopic, thermal-radiometric, radar, and occultation results are synthesized in order to derive a coherent model for Eros. The geometric albedo is 0.19±0.01 at the visual wavelength, and the overall dimensions are approximately 13 × 15 × 36km. The rotation is about the short axis, in the direct sense, with a sidereal period of 5h16m13s.4. The pole of rotation lies within a few degrees of ecliptic coordinates λ = 16° and β = + 11°.Eros is uniformly coated with a particulate surface layer several millimeters thick. It has an iron-bearing silicate composition, similar to that of a minority of main-belt asteroids, and probably identifiable with H-type ordinary chondrites. 相似文献