Helios 1 energetic particle observations of the solar gamma-ray/neutron flare events of 1982 June 3 and 1980 June 21

Journal Article · Fri Mar 15 04:00:00 EST 1985 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184445· OSTI ID:5660055

McDonald, F B; Van Hollebeke, M A.I.

The characteristics of the energetic particles associated with the solar ..gamma..-ray/neutron flare events of 1982 June 3 and 1980 June 21 observed by the Goddard cosmic-ray experiment on Helios 1 (at heliocentric distances of 0.57 and 0.54 AU, respectively) differ in several important respects from typical solar particle increases. In particular, the 1982 June 3 event has a proton energy spectrum which fits a remarkable flat power law in kinetic energy with a spectral index of 1.2, an electron/proton ratio of 1 at 4 MeV, and a small but well-defined precursor event that began some 3 hr before the impulsive flare increase. Similar energetic particle precursors were observed for the ..gamma..-ray associated 1980 June 21 and June 7 flare events. At energies less than approx.40 MeV, the particle onset time measured for the 1982 June 3 event is anomalous, suggesting that these lower energy paritcles may have been released at the Sun approx. 1-2 minutes before the higher energy particles.

• Research Organization: National Aeronautics and Space Administration
• OSTI ID: 5660055
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 290:2; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
BARYONS
COSMIC RAY DETECTION
DETECTION
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
GAMMA RADIATION
HADRONS
IONIZING RADIATIONS
NEUTRONS
NUCLEONS
PLASMA ACCELERATION
RADIATION DETECTION
RADIATIONS
SOLAR ACTIVITY
SOLAR FLARES
SOLAR NEUTRONS
SOLAR PARTICLES
SOLAR RADIATION
STELLAR RADIATION