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Title: OBSERVATION OF A MORETON WAVE AND WAVE-FILAMENT INTERACTIONS ASSOCIATED WITH THE RENOWNED X9 FLARE ON 1990 MAY 24

Journal Article · · Astrophysical Journal
 [1]; ; ;  [2];  [3];  [4]
  1. CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China)
  2. Space Weather Research Laboratory, Center for Solar-Terrestrial Research, NJIT, Newark, NJ 07102 (United States)
  3. Lockheed Martin Solar and Astrophysics Laboratory, Building 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)
  4. Institute of Physics and Astronomy, University of Potsdam, D-14476 Potsdam (Germany)

Using Big Bear Solar Observatory film data recently digitized at NJIT, we investigate a Moreton wave associated with an X9 flare on 1990 May 24, as well as its interactions with four filaments F1-F4 located close to the flaring region. The interaction yields interesting insight into physical properties of both the wave and the filaments. The first clear Moreton wavefront appears at the flaring-region periphery at approximately the same time as the peak of a microwave burst and the first of two {gamma}-ray peaks. The wavefront propagates at different speeds ranging from 1500-2600 km s{sup -1} in different directions, reaching as far as 600 Mm away from the flaring site. Sequential chromospheric brightenings are observed ahead of the Moreton wavefront. A slower diffuse front at 300-600 km s{sup -1} is observed to trail the fast Moreton wavefront about one minute after the onset. The Moreton wave decelerates to {approx}550 km s{sup -1} as it sweeps through F1. The wave passage results in F1's oscillation which is featured by {approx}1 mHz signals with coherent Fourier phases over the filament, the activation of F3 and F4 followed by gradual recovery, but no disturbance in F2. Different height and magnetic environment together may account for the distinct responses of the filaments to the wave passage. The wavefront bulges at F4, whose spine is oriented perpendicular to the upcoming wavefront. The deformation of the wavefront is suggested to be due to both the forward inclination of the wavefront and the enhancement of the local Alfven speed within the filament channel.

OSTI ID:
22130936
Journal Information:
Astrophysical Journal, Vol. 773, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English