分类: 天文学 >> 天文仪器与技术 提交时间: 2024-06-06 合作期刊: 《天文技术与仪器(英文)》
摘要:The Educational Adaptive-optics Solar Telescope (EAST) at the Shanghai Astronomy Museum has been running routine astronomical observations since 2021. It is a 65-cm-aperture Gregorian solar telescope for scientific education, outreach, and research. The telescope system is designed in an “open” format so that the solar tower architecture can be integrated with it, and visitors can watch the observations live from inside the tower. Equipped with adaptive optics, a high-resolution imaging system, and an integral field unit spectro-imaging system, this telescope can obtain high-resolution solar images in the TiO and Hα bands, and perform spectral image reconstruction using 400 optical fibers at selected wavelengths. It can be used not only in public education and scientific outreach but also in solar physics research.
分类: 天文学 >> 天文仪器与技术 提交时间: 2024-04-18 合作期刊: 《天文技术与仪器(英文)》
摘要:Strong atmospheric turbulence reduces astronomical seeing, causing speckle images acquired by groundbased solar telescopes to become blurred and distorted. Severe distortion in speckle images impedes image phase deviation in the speckle masking reconstruction method, leading to the appearance of spurious imaging artifacts. Relying only on linear image degradation principles to reconstruct solar images is insufficient. To solve this problem, we propose the multiframe blind deconvolution combined with non-rigid alignment (MFBD-CNRA) method for solar image reconstruction. We consider image distortion caused by atmospheric turbulence and use non-rigid alignment to correct pixel-level distortion, thereby achieving nonlinear constraints to complement image intensity changes. After creating the corrected speckle image, we use the linear method to solve the wavefront phase, obtaining the target image. We verify the effectiveness of our method results, compared with others, using solar observation data from the 1 m new vacuum solar telescope (NVST). This new method successfully reconstructs high-resolution images of solar observations with a Fried parameter r0 of approximately 10 cm, and enhances images at high frequency. When r0 is approximately 5 cm, the new method is even more effective. It reconstructs the edges of solar graining and sunspots, and is greatly enhanced at mid and high frequency compared with other methods. Comparisons confirm the effectiveness of this method, with respect to both nonlinear and linear constraints in solar image reconstruction. This provides a suitable solution for image reconstruction in ground-based solar observations under strong atmospheric turbulence.
分类: 天文学 >> 天文仪器与技术 提交时间: 2024-02-07 合作期刊: 《天文技术与仪器(英文)》
摘要:The Solar Close Observations and Proximity Experiments (SCOPE) mission, which has been proposed by the Yunnan Observatories, Chinese Academy of Sciences, aiming to operate at a distance of 5 to 10 solar radii from the Sun, plans to complete the in situ detection of the solar eruption process and observation of the magnetic field structure response. The solar flux received by the satellite ranges from 103 to 106 Wm−2, which poses challenges for thermal management of the solar arrays. In this work, the solar array cooling system of the Parker Solar Probe is discussed, the developments of the fluid loop technique are reviewed, and a research plan for a next-generation solar array cooling system is proposed. This paper provides a valuable reference for novel thermal control systems in spacecraft for solar observation.
分类: 天文学 >> 天文仪器与技术 提交时间: 2024-02-07 合作期刊: 《天文技术与仪器(英文)》
摘要:In this paper, the mission and the thermal environment of the Solar Close Observations and Proximity Experiments (SCOPE) spacecraft are analyzed, and an advanced thermal management system (ATMS) is designed for it. The relationship and functions of the integrated database, the intelligent thermal control system and the efficient liquid cooling system in the ATMS are elaborated upon. For the complex thermal field regulation system and extreme space thermal environment, a modular simulation and thermal field planning method are proposed, and the feasibility of the planning algorithm is verified by numerical simulation. A solar array liquid cooling system is developed, and the system simulation results indicate that the temperatures of the solar arrays meet the requirements as the spacecraft flies by perihelion and aphelion. The advanced thermal management study supports the development of the SCOPE program and provides a reference for the thermal management in other deep-space exploration programs.
分类: 天文学 >> 天文学 提交时间: 2023-12-29
摘要: Magnetars are neutron stars with extremely strong magnetic fields, frequently powering high-energy activity in X-rays. Pulsed radio emission following some X-ray outbursts have been detected, albeit its physical origin is unclear. It has long been speculated that the origin of magnetars' radio signals is different from those from canonical pulsars, although convincing evidence is still lacking. Five months after magnetar SGR 1935+2154's X-ray outburst and its associated Fast Radio Burst (FRB) 20200428, a radio pulsar phase was discovered. Here we report the discovery of X-ray spectral hardening associated with the emergence of periodic radio pulsations from SGR 1935+2154 and a detailed analysis of the properties of the radio pulses. The complex radio pulse morphology, which contains both narrow-band emission and frequency drifts, has not been seen before in other magnetars, but is similar to those of repeating FRBs - even though the luminosities are many orders of magnitude different. The observations suggest that radio emission originates from the outer magnetosphere of the magnetar, and the surface heating due to the bombardment of inward-going particles from the radio emission region is responsible for the observed X-ray spectral hardening.