Estimate of cosmic-ray latitudinal gradients in 1981-1982

Journal Article · Thu Mar 15 04:00:00 EST 1984 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184238· OSTI ID:6675648

Decker, R B; Krimigis, S B; Venkatesan, D

We report an analysis of greater than 70 MeV galactic cosmic-ray proton gradients measured by Voyager 1 and Voyager 2 during the 17 month period from early 1981 through mid-1982. This period coincides with the initial phase of cosmic-ray recovery following a minimum reached in late 1980 to early 1981. During this interval, the two spacecraft remain within 4/sup 0/ of one another in heliolongitude, with Voyagers 1 and 2 moving in helioradius from 9.8 to 13.2 Au and 8.2 to 10.1 AU respectively. The Voyagers increase their heliolatitude separation from 3/sup 0/ to 16/sup 0/ as Voyager 1 moves from 2/sup 0/ south to 13/sup 0/ north of the helioequatorial plane at the rate of 1.5 per month following its encounter with Saturn in late 1980. We find that the intensity difference between the two spacecraft is consistent with either a positive radial gradient of approximately 2% per AU (assuming zero heliolatitude gradient), or a small heliolatiatude gradient of approximately 0.4% per degree (assuming zero helioradial gradient). At present, we are unable to make an unambiguous separation between the radial and latitudinal effects.

• Research Organization: Applied Physics Laboratory, The Johns Hopkins University
• OSTI ID: 6675648
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 278:2; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMIC PROTONS
COSMIC RADIATION
COSMIC RAY DETECTION
DETECTION
ELEMENTARY PARTICLES
FERMIONS
GALAXIES
HADRONS
INTERPLANETARY SPACE
IONIZING RADIATIONS
MILKY WAY
NUCLEONS
PROTONS
RADIATION DETECTION
RADIATIONS
SPACE
SPACE VEHICLES
VEHICLES
VOYAGER SPACE PROBES