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Dynamical phenomena in sunspots. I - Observing procedures and oscillatory phenomena. II - A moving magnetic featureHigh resolution spectra consisting of at least 1 hr periods were obtained of the sunpost atmosphere. The Ca II H and K lines were scanned to characterize umbral oscillations and flashes. The former displayed peaks lasting 150-197 sec, while penumbral oscillations peaked in the 197-300 sec range. Quiet sun oscillations exhibited no peaks under 300 sec. The Ca II K line umbral flashes were ubiquitous for all observational periods and were associated with light bridges in the umbra. Magnetic field, vertical velocity, and chromospheric intensity measurements taken during the 1 hr scans covered moving magnetic features (MMF), which traversed the moats around sunspots. MMF areas increased while the magnetic field intensity decreased with MMF movement away from a sunspot. Bright Ca II K line wings were apparent in the MMFs, but cores of the lines were not observed, suggesting that flux loops generating the line are low in the photosphere.
Document ID
19850031716
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Thomas, J. H.
(Rochester, University; C. E. Kenneth Mees Observatory, Rochester, NY; Sacramento Peak Observatory, Sunspot, NM, United States)
Cram, L. E.
(Commonwealth Scientific and Industrial Research Organization, Div. of Applied Physics, Lindfield New South Wales, Australia)
Nye, A. H.
(Rochester Institute of Technology, Rochester, NY; Sacramento Peak Observatory, Sunspot NM, United States)
Date Acquired
August 12, 2013
Publication Date
October 1, 1984
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 285
ISSN: 0004-637X
Subject Category
Solar Physics
Accession Number
85A13867
Funding Number(s)
CONTRACT_GRANT: NSG-7562
CONTRACT_GRANT: NSF ATM-80-21305
Distribution Limits
Public
Copyright
Other

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