Infrared continuum observations of five-minute oscillations

✍ Scribed by C. A. Lindsey

• Book ID: 104642973
• Publisher: Springer
• Year: 1977
• Tongue: English
• Weight: 920 KB
• Volume: 52
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00149644

✦ Synopsis

Infrared continuum observations of the Sun at wavelengths between 10p, and 30p, show a nonisothermal response of the upper photosphere to compression waves associated with the fiveminute oscillations. Observations were made with four broad-band filters with effective transmission wavelengths between 10p, and 26ix and with a 10" aperture. Further observations at submillimeter wavelengths with a 2' aperture did not resolve oscillatory fluctuations of five-minute period.

Comparisons with velocity field data of Howard (1976) suggest that the relaxation time of the photosphere exceeds (300/2w) seconds at the height of formation of the 26p, continuum (~soooA-10-2). The photosphere reponds to 3 mHz oscillatory motion with considerably less cgmpression than expected for simple acoustic modes in an adiabatically responsive atmosphere, confirming the evanescent character of the five-minute oscillations.