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Spectral and Imaging Observations of a C2.3 White-Light Flare from the Advanced Space-Based Solar Observatory (ASO-S) and the Chinese HαSolar Explorer (CHASE)
Lei, Shijun; Chen, Wei; Feng, Li +27 more
Solar white-light flares are characterized by an enhancement in the optical continuum, which are usually large flares (X- and M-class flares). Here, we report a small C2.3 white-light flare (SOL2022-12-20T04:10) observed by the Advanced Space-based Solar Observatory and the Chinese HαSolar Explorer (CHASE). This flare exhibits an increase of ≈ 6.4…
Spectra and Anisotropy of Solar Energetic Protons During GLE #65 on 28 October, 2003 and GLE #66 on 29 October, 2003
Mishev, Alexander L.; Koldobskiy, Sergey A.; Larsen, Nicholas +1 more
Solar Cycle 23 was the most active in ground-level enhancements (GLEs) with 16 events registered by the global neutron monitor network. In this paper, we study a very active period in October–November, 2003, which revealed an intense solar activity burst that led to several eruptive processes and produced a sequence of three GLEs. By applying stat…
Reconstruction of Carrington Rotation Means of Open Solar Flux over the Past 154 Years
Lockwood, Mike; Owens, Mat
We generate reconstructions of signed open solar flux (OSF) for the past 154 years using observations of geomagnetic activity. Previous reconstructions have been limited to annual resolution, but this is here increased by a factor of more than 13 by using averages over Carrington rotation (CR) intervals. We use two indices of geomagnetic activity,…
The Sun's Large-Scale Flows I: Measurements of Differential Rotation & Torsional Oscillation
Basu, Sarbani; Pevtsov, Alexei A.; DeRosa, Marc L. +13 more
We have developed a comprehensive catalog of the variable differential rotation measured near the solar photosphere. This catalog includes measurements of these flows obtained using several techniques: direct Doppler, granule tracking, magnetic pattern tracking, global helioseismology, as well as both time-distance and ring-diagram methods of loca…
Origin of the Chromospheric Umbral Waves in Sunspots
Xu, Zhe; Xue, Zhike; Yan, Xiaoli +5 more
Oscillations are ubiquitous in sunspots and the associated higher atmospheres. However, it is still unclear whether these oscillations are driven by the external acoustic waves (p-modes) or generated by the internal magnetoconvection. To obtain clues about the driving source of umbral waves in sunspots, we analyzed the spiral wave patterns (SWPs) …
Triangulation of Hard X-Ray Sources in an X-Class Solar Flare with ASO-S/HXI and Solar Orbiter/STIX
Massa, Paolo; Krucker, Säm; Chen, Wei +4 more
HXI on ASO-S and STIX onboard Solar Orbiter are the first simultaneously operating solar hard X-ray imaging spectrometers. ASO-S's low Earth orbit and Solar Orbiter's periodic displacement from the Sun–Earth line enables multi-viewpoint solar hard X-ray spectroscopic imaging analysis for the first time. Here, we demonstrate the potential of this n…
The Solar Origin of an Intense Geomagnetic Storm on 1 December 2023: Successive Slipping and Eruption of Multiple Magnetic Flux Ropes
Hou, Yijun; Li, Ting; Feng, Li +12 more
The solar eruption that occurred on 28 November 2023 (SOL2023-11-28) triggered an intense geomagnetic storm on 1 December 2023. The associated terrestrial auroras manifested at the most southern latitudes in the northern hemisphere observed in the past two decades. In order to explore the profound geoeffectiveness of this event, we conducted a com…
Observations of the Polarized Solar Corona During the Annular Eclipse of 14 October 2023
West, Matthew J.; Alzate, Nathalia; Seaton, Daniel B. +10 more
We present results of a dual eclipse expedition to observe the solar corona from two sites during the annular solar eclipse of 14 October 2023 using a novel coronagraph designed to be accessible for amateurs and students to build and deploy. The coronagraph (CATEcor) builds on the standardized eclipse observing equipment developed for the Citizen …
Association Between a Failed Prominence Eruption and the Drainage of Mass from Another Prominence
Feng, Li; Lu, Lei; Li, Qiao +31 more
Sympathetic eruptions of solar prominences have been studied for decades, however, it is usually difficult to identify their causal links. Here, we present two failed prominence eruptions on 26 October 2022 and explore their connections. Using stereoscopic observations, the South prominence (PRO-S) erupts with untwisting motions, flare ribbons occ…
Calibration and Release of Magnetograms/Dopplergrams Obtained at the Mt. Wilson 150-Foot Tower Telescope (MWO)
Ulrich, Roger K.; Boyden, John; Tran, Tham
The Mt. Wilson Observatory archive of observations of solar disk magnetic fields, Doppler velocities, and spectral line intensities is a resource for studying the Sun's state from 1967 to 2013. Instrument changes/upgrades during this time must be considered when interpreting this record. Portions of this record have been previously released. This …