First performances of the GOLF-NG instrumental prototype observing the Sun in Tenerife

TL;DR

The paper reports the first solar observations using the GOLF-NG prototype spectrometer in Tenerife, demonstrating its capability to measure solar oscillations at multiple atmospheric heights and validating its performance against existing instruments.

Contribution

This study presents the first successful solar observations with the GOLF-NG prototype, showcasing multi-height Doppler measurements and initial validation of its observational strategy.

Findings

Detection of 5-minute oscillations at different solar atmospheric heights

Comparison with GOLF/SOHO and Mark-I confirms measurement consistency

Prototype running successfully over summer 2008 for performance assessment

Abstract

The primary challenge of GOLF-NG (Global Oscillations at Low Frequency New Generation) is the detection of the low-frequency solar gravity and acoustic modes, as well as the possibility to measure the high-frequency chromospheric modes. On June 8th 2008, the first sunlight observations with the multichannel resonant GOLF-NG prototype spectrometer were obtained at the Observatorio del Teide (Tenerife). The instrument performs integrated (Sun-as-a-star), Doppler velocity measurements, simultaneously at eight different heights in the D1 sodium line profile, corresponding to photospheric and chromospheric layers of the solar atmosphere. In order to study its performances, to validate the conceived strategy, and to estimate the necessary improvements, this prototype has been running on a daily basis over the whole summer of 2008 at the Observatorio del Teide. We present here the results of the first GOLF-NG observations, clearly showing the characteristics of the 5-minute oscillatory signal at different heights in the solar atmosphere. We compare these signals with simultaneous observations from GOLF/SOHO and from the Mark-I instrument -- a node of the BiSON network, operating at the same site.