A New Multi-wavelength Solar Telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)

TL;DR

The ONSET telescope enables simultaneous high-resolution imaging of solar eruptions across multiple wavelengths, capturing dynamics in the corona, chromosphere, and photosphere for improved solar activity understanding.

Contribution

This paper introduces the design, construction, and initial deployment of the novel multi-wavelength ONSET solar telescope, enhancing solar eruption observation capabilities.

Findings

Successful observation of solar eruptions in three wavelengths

High spatial and temporal resolution imaging achieved

Stable seeing conditions at the new site

Abstract

A new multi-wavelength solar telescope, Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, was constructed, being fabricated by Nanjing Institute of Astronomical Optics & Technology and run in cooperation with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He {\small I} 10830 \AA, H$\alpha$, and white-light at 3600 \AA and 4250 \AA, which are selected in order to obtain the dynamics in the corona, chromosphere, and the photosphere simultaneously. Full-disk or partial-disk solar images with a field of 10 arcmin at three wavelengths can be obtained nearly simultaneously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and of high quality. We give a brief description of the scientific objectives and the basic structure of the ONSET. Some preliminary results are also presented.