Actual Status and Early Results from GOLF Experiment on-board SOHO

Roca Cortes, T.; Gabriel, A. H.; Charra, J.; Grec, G.; Ulrich, R. K.; Turck-Chieze, S.; Robillot, J. M.; Boumier, P.; Régulo, C.; Baudin, F.; Lazrek, M.; Garcia, R. A.; Palle, P. L.; GOLF Team
Bibliographical reference

1st Advances in Solar Physics Euroconference. Advances in Physics of Sunspots, ASP Conf. Ser. Vol. 118., Eds.: B. Schmieder, J.C. del Toro Iniesta, & M. Vazquez, p. 249.

Advertised on:
0
1997
Number of authors
14
IAC number of authors
3
Citations
1
Refereed citations
1
Description
GOLF is a resonant scattering spectrophotomer which is flying onboard SOHO. The first four months were dedicated to the commissioning and calibration of the instrument which led to the conclusion of a performance within design specification at system and subsystem levels. However, mal-functioning of the polarising mechanisms at the end of this period led to the adoption of an unplanned operating sequence in which the mechanisms are no longer used. This photometric mode, which measures at two points on the blue wing of the solar sodium lines, has very little effect on the possibility of reaching the first objective of the mission: measuring the solar spectrum of normal modes. However, the precise calibration procedure to transform the actual measurements into velocity is not trivial. The actual operating mode allows the obtention of continuous data without interruptions which is producing exceptionally noise-free p-mode spectra. Although this spectrum is being studied, the data accumulated do not allow a positive detection of the g-mode spectrum yet. On the other hand, the present mode of operation do not show any indication of degradation which could limit its use for up to 6 years or more of operation.