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| Paper: |
Solar Global Oscillations of Low-Degree modes (GOLD):
The Status of the Multi-channel Resonance Spectrometer GOLF-NG |
| Volume: |
462, Progress in Solar/Stellar Physics with Helio- and Asteroseismology |
| Page: |
240 |
| Authors: |
Turck-Chièze, S.; Carton, P.-H.; Barrière, J.-C.; Pallé, P. L.; Robillot, J.-M.; Ballot, J.; Chenus, A.-C.; Daniel-Thomas, P.; Delbart, A.; García, R. A.; Granelli, R.; Lahonde-Hamdoun, C.; Loiseau, D.; Mathur, S.; Piret, Y.; Salabert, D.; Simoniello, R.; Davies, G. R. |
| Abstract: |
Low-degree pulsation modes are the best way to scrutinize stellar cores.
They also provide, due to their intrinsic nature,
a way to follow varying activity in important subsurface layers.
Following difficulties encountered with the Solar and Heliospheric Observatory (SoHO) in 1998,
we study a new design that improves the detection at
low and high frequencies in comparison with the Global Oscillations at Low Frequency (GOLF) instrument.
It is based on a substantial increase in the counting rates to get better photon statistics,
and a reduction of the solar turbulent noise in measuring simultaneously the
Doppler velocity at 6-7 heights in the strong sodium spectral line.
A prototype, GOLF-NG (GOLF New Generation), has been built with numerous laboratory checks of the performance
and in situ solar measurements at Tenerife in 2008 and 2010.
All the required specifications are now achieved, and
so GOLD can be prepared for space observations with balloons or satellites.
The substantial improvements allow
an improved detection of weak signals at different frequencies and
information on activity indicators, as the Na D lines are
sensitive to the magnetic field between photosphere and chromosphere. |
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