Observations of the Zodiacal Light from a Sounding Rocket

Abstract

view Abstract Citations (54) References (33) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Observations of the Zodiacal Light from a Sounding Rocket Wolstencroft, R. D. ; Rose, L. J. Abstract The surface brightness and state of polarization of the zodiacal light at elongations 30 < E < 1 7S have been measured from a sounding rocket. Observations were secured over a wide range of ecliptic latitude and longitude, including regions near the north ecliptic pole and the antisolar point. The major observational results are: (1) the maximum degree of polarization at 7000 A is 20 per cent at E 75 (2) at E > 165 the polarization plane of the zodiacal light is parallel to the scattering plane (negative polarization); (3) significant circular polarization was found in only one region of the night sky, namely at 40 < E < 65 close to the ecliptic, where the average degree of ellipticity was -2.9 per cent: this circular polarization should most probably be attributed to the zodiacal light; (4) the B - R color index of the zodiacal light is close to that of the Sun at e < 70 : however, beyond t = 110 the zodiacal light is bluer than the Sun; and (5) the brightness near the south ecliptic pole exceeds that near the north ecliptic pole by about 15 per cent. Three models of the interplanetary dust cloud comprising miztures of spherical particles composed of Fe, SiO2, and H2O show a measure of agreement with observation. It is shown that the presence of ice particles smaller than 100 within 7 a.u. of the Sun is unlikely; the two models containing ice particles are therefore less realistic than the model containing Fe and SiO2 only. A proportion of particles which are asymmetric in composition or shape are required to explain the observed circular polarization. Publication: The Astrophysical Journal Pub Date: January 1967 DOI: 10.1086/148998 Bibcode: 1967ApJ...147..271W full text sources ADS |