Wavelength dependence of polarization. IV. Volcanic cinders and particles

view Abstract Citations (9) References (7) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Wavelength dependence of polarization. IV. Volcanic cinders and particles Coffeen, David L. Abstract Five laboratory samples were measured for comparison with the moon, using a Wollaston photopolari meter with filters near 0.36, 0.53, and 0.97 , having the sun as light source. Three of the samples were porous dust layers of ground volcanic cinder particles smaller than 37 , in "fairy-castle" structures. The other two were: a porous but solid lava fragment, and the same fragment covered with a fairy-castle dust layer made from the same lava. The solid lava fragment is more highly polarized than the moon, and has essentially no wavelength dependence. The wavelength and phase dependence of the lunar polarization is closely matched by the fairy-castle structures. No dependence of polarization on sample orientation was found for the volcanic materials. Differential photometry was done with the same filters using a smoked MgO layer as comparison. All samples show a linear brightness increase (in magnitudes) from 50 to 20 phase, similar to the moon. The fairy-castle structures show an appreciable opposition effect in the ultra- violet which, however, almost disappears in the green and infrared. Publication: The Astronomical Journal Pub Date: August 1965 DOI: 10.1086/109755 Bibcode: 1965AJ.....70..403C full text sources ADS | Related Materials (44) Part 1: 1960AJ.....65..466G Part 2: 1960PGLO...40..467G Part 3: 1960AJ.....65..470G Part 4: 1960PGLO...41..470G Part 5: 1964AJ.....69..826G Part 6: 1964PGLO...62..826G Part 7: 1965AJ.....70..447G Part 9: 1965AJ.....70..579G Part 10: 1966AJ.....71...62G Part 11: 1966AJ.....71..111G Part 12: 1966AJ.....71..355C Part 13: 1967AJ.....72..631G Part 14: 1967AJ.....72..887C Part 15: 1968AJ.....73...20C Part 16: 1968AJ.....73..677K Part 17: 1969AJ.....74...85S Part 18: 1969AJ.....74..190G Part 19: 1969AJ.....74..433C Part 20: 1969AJ.....74..446C Part 21: 1969AJ.....74..528C Part 22: 1969AJ.....74.1179C Part 23: 1969AJ.....74.1066P Part 24: 1970AJ.....75...54C Part 25: 1970AJ.....75..182Z Part 26: 1971AJ.....76..645Z Part 27: 1971AJ.....76..651Z Part 28: 1971AJ.....76..576K Part 29: 1974AJ.....79..565C Part 30: 1974AJ.....79..581C Part 31: 1974AJ.....79..590G Part 32: 1975AJ.....80..595S Part 33: 1975AJ.....80..602S Part 34: 1975AJ.....80..702C Part 35: 1976AJ.....81..641K Part 36: 1977AJ.....82..908C Part 37: 1979AJ.....84..356C Part 38: 1979AJ.....84..671G Part 39: 1979AJ.....84.1244S Part 40: 1979AJ.....84..683L Part 41: 1979AJ.....84.1200C Part 42: 1979AJ.....84.1419D Part 43: 1979AJ.....84.1802S Part 44: 1980AJ.....85..564S Part 45: 1980AJ.....85..751S