The Lyman-alpha Solar Telescope (LST) for the ASO-S mission – II. design of LST

Abstract

As one of the three payloads for the Advanced Space-based Solar Observatory (ASO-S) mission, the Lyman-alpha (Lyα) Solar Telescope (LST) is composed of three instruments: a Solar Corona Imager (SCI), a Lyα Solar Disk Imager (SDI) and a full-disk White-light Solar Telescope (WST). When working in-orbit, LST will simultaneously perform high-resolution imaging observations of all regions from the solar disk to the inner corona up to 2.5 R⊙ (R⊙ stands for the mean solar radius) with a spatial resolution of 4.8″ and 1.2″ for coronal and disk observations, respectively, and a temporal resolution of 30 – 120 s and 1 – 120 s for coronal and disk observations, respectively. The maximum exposure time can be up to 20 s due to precise pointing and image stabilization function. Among the three telescopes of LST, SCI is a dual-waveband coronagraph simultaneously and independently observing the inner corona in the HI Lyα (121.6±10 nm) line and white light (WL) (700±40 nm) wavebands by using a narrowband Lyα beam splitter and has a field of view (FOV) from 1.1 to 2.5 R⊙. The stray-light suppression level can attain <10−6 B⊙ (B⊙ is the mean brightness of the solar disk) at 1.1 R⊙ and ≤5×10−8 B⊙ at 2.5 R⊙. SDI and WST are solar disk imagers working in the Lyα line and 360.0 nm wavebands, respectively, which adopt an off-axis two-mirror reflective structure with an FOV up to 1.2 R⊙, covering the inner coronal edge area and relating to coronal imaging. We present the up-to-date design for the LST payload.

CAMEL. II. A 3D Coronal Mass Ejection Catalog Based on Coronal Mass Ejection Automatic Detection with Deep Learning

“…We are accumulating a large amount of coronagraph polarization data observed by, e.g., COR1 in the instrument suit SECCHI (Howard et al 2008) on board STEREO, the Multi Element Telescope for Imaging and Spectroscopy (Antonucci et al 2020) on board the Solar Orbiter, the Lyα Solar Telescope (Chen et al 2019;Feng et al 2019;Li et al 2019) on board the Advanced Spaced-based Solar Observatory, and the Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun (Renotte et al 2015) on board Proba-3. An automatic 3D catalog is vital for the operational prediction of the CME arrival on Earth and for statistical studies of CME physics.…”

Stray-Light Suppression of the Internally Occulted Reflecting Solar Corona Imager

“…The representative ones are OSO-7 in 1971, Skylab-HAO in 1973, SOHO LASCO-C1 in 1995, STEREO SECCHI-COR1 in 2006, Solar Orbiter-Metis in 2020, and ADITYA-L1 VELC planned for launch in 2022 [1][2][3][4][5][6]. Advanced Spacebased Solar Observatory (ASO-S) is a mission proposed for the 25th solar maximum by the Chinese solar physics community, which is scheduled to be launched in 2022 for imaging the inner corona from 1.1 to 2.5 R ⊙ in the Lyman-alpha (121.6 ± 10nm) line and white-light (700.0 ± 40 nm) wavebands, which will not only advance our understanding of the underlying physics of solar eruptions but also help to improve forecast capability of space weather [7].…”

Space Weather Related to Solar Eruptions With the ASO-S Mission

“…We also have an operational objective, that is, to observe solar eruptions and magnetic fields, and provide data products to different space weather prediction centers in China for designing suitable forecast products and making corresponding forecasts. To fulfill its major scientific and operational objectives, the Chinese solar physics community proposed the ASO-S mission, which has three elaborately designed payloads: the Full-disc vector MagnetoGraph (FMG, [11,12]), the Lyman-alpha (Lyα) Solar Telescope (LST, [13][14][15]), and the Hard X-ray Imager (HXI, [16,17]) dedicated to observe magnetic fields, CMEs, and flares, respectively.…”