Helioseismology from the South Pole: Comparison of 1987 and 1981 results

Details Helioseismology from the South Pole: Comparison of 1987 and 1981 results Helioseismology from the South Pole: Comparison of 1987 and 1981 results

Dec 1988

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1988esasp.286..279j&link_type=abstract

In ESA, Seismology of the Sun and Sun-Like Stars p 279-284 (SEE N89-25819 19-92)

Computer Science

44

Helioseismology, Solar Interior, Solar Oscillations, Sun, Annual Variations, Ground Stations, P Waves, Solar Activity, Solar Rotation

Scientific paper

Full disk images with 10 arc sec pixels and filtered to a 7 A pass band centered on the Ca II K line were obtained from the geographic South Pole in 1981 and 1987. In 1981, 50hr of essentially uninterrupted data were obtained. In 1987, three such runs were obtained over a period of 325 hours for a duty cycle of 47 percent. The 1987 observations are characterized by a much lower level of solar activity than 1981, a much improved CCD camera, considerably better image stability and a varying amount of instrumental scatter. The 1987 data have a substantially better signal-to-noise ratio than the 1981 data so that oscillations with degrees from 0 to 150 and frequencies from 2 to 7 mHz are well observed. The observations were reduced to spectra in l, m, and v. A comparison of p-mode frequencies measured in 1981 and 1987, and coefficients of Legendre polynomial expansions of frequency shifts caused by solar rotation are presented. The time behavior of systematic frequency shifts which depend upon m but which do not arise from rotation is described.

Affiliated with

Also associated with

No associations

Rating

Helioseismology from the South Pole: Comparison of 1987 and 1981 results does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Helioseismology from the South Pole: Comparison of 1987 and 1981 results, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Helioseismology from the South Pole: Comparison of 1987 and 1981 results will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1756045