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Abstract The spectra of coronal mass ejections (CMEs) in the low corona play a crucial role in understanding their origins and physical mechanisms and enhancing space weather forecasting. However, capturing these spectra faces significant challenges. This paper introduces a scheme of a multislit spectrometer design with five slits, acquiring the global spectra of the solar corona simultaneously with a focus on the spectra of CMEs in the low corona. The chosen wavelength range of the spectrometer (170–180 Å) includes four extreme ultraviolet emission lines (Fex174.53 Å, Feix171.07 Å, Fex175.26 Å, Fex177.24 Å), which provides information on the plasma velocity, density, and temperature. Utilizing a numerical simulation of the global corona for both the on-disk and the off-limb scenarios, we focus on resolving the ambiguity associated with various Doppler velocity components of CMEs, particularly for a fast CME in the low corona. A new application of our decomposition technique is adopted, enabling the successful identification of multiple discrete CME velocity components. Our findings demonstrate a strong correlation between the synthetic model spectra and the inverted results, indicating the robustness of our decomposition method and its significant potential for global monitoring of the solar corona, including CMEs. 

Abstract Heterotrimeric G-proteins, composed of Gα, Gβ, and Gγ subunits, are involved in the regulation of multiple signaling pathways in plants. OsDEP1 (a Gγ subunit) of rice and TaNBP1 (a Gβ subunit) of wheat are homologs of Arabidopsis AGG3 and AGB1, respectively, which are regulators of grain size and also involved in nitrogen responses. However, the function of Arabidopsis G-proteins in nitrogen utilization under different nitrogen conditions has not been fully investigated. In this study, to evaluate the role of Arabidopsis G-proteins in yield and nitrogen use efficiency (NUE), overexpression transgenic lines AtGPA1, AtAGB1 together with AtAGG1 (AGB1-AGG1), AtAGB1 together with AtAGG2 (AGB1-AGG2), and AtAGB1 together with AtAGG3 (AGB1-AGG3) were created in Brassica napus ‘K407’. Analysis of multiple transgenic B. napus lines showed that overexpression of GPA1, AGB1-AGG1, AGB1-AGG2, or AGB1-AGG3 led to increased biomass of seedling plants, including a well-developed root system, and increased nitrogen uptake under low and high nitrogen conditions. The activity of glutamine synthetase, a key nitrogen assimilating enzyme, and the expression levels of genes that are involved in nitrogen uptake and assimilation were significantly increased in overexpression plants under the low nitrogen condition. These properties enabled overexpression plants to increase the number of seeds per silique by 12–27% only under the low nitrogen condition, effectively improving yield per plant by 9–69% and NUE by 7–49%. These results reveal roles of G-proteins in regulating seed traits and NUE, and provide a strategy that can substantially improve crop yield and NUE. 

Abstract Full-disk spectroscopic observations of the solar corona are highly desired to forecast solar eruptions and their impact on planets and to uncover the origin of solar wind. In this paper, we introduce a new multislit design (five slits) to obtain extreme-ultraviolet (EUV) spectra simultaneously. The selected spectrometer wavelength range (184–197 Å) contains several bright EUV lines that can be used for spectral diagnostics. The multislit approach offers an unprecedented way to efficiently obtain the global spectral data but the ambiguity from different slits should be resolved. Using a numerical simulation of the global corona, we primarily concentrate on the optimization of the disambiguation process, with the objective of extracting decomposed spectral information of six primary lines. This subsequently facilitates a comprehensive series of plasma diagnostics, including density (Fexii195.12/186.89 Å), Doppler velocity (Fexii193.51 Å), line width (Fexii193.51 Å), and temperature diagnostics (Feviii185.21 Å, Fex184.54 Å, Fexi188.22 Å, and Fexii193.51 Å). We find a good agreement between the forward modeling parameters and the inverted results at the initial eruption stage of a coronal mass ejection, indicating the robustness of the decomposition method and its immense potential for global monitoring of the solar corona. 

Abstract Radio bursts from nearby active M-dwarfs have been frequently reported and extensively studied in solar or planetary paradigms. Whereas, their substructures or fine structures remain rarely explored despite their potential significance in diagnosing the plasma and magnetic field properties of the star. Such studies in the past have been limited by the sensitivity of radio telescopes. Here we report the inspiring results from the high time-resolution observations of a known flare star AD Leo with the Five-hundred-meter Aperture Spherical radio Telescope. We detected many radio bursts in the 2 days of observations with fine structures in the form of numerous millisecond-scale sub-bursts. Sub-bursts on the first day display stripe-like shapes with nearly uniform frequency drift rates, which are possibly stellar analogs to Jovian S-bursts. Sub-bursts on the second day, however, reveal a different blob-like shape with random occurrence patterns and are akin to solar radio spikes. The new observational results suggest that the intense emission from AD Leo is driven by electron cyclotron maser instability, which may be related to stellar flares or interactions with a planetary companion. 

Abstract Extreme-ultraviolet late phase (ELP) refers to the second extreme-ultraviolet (EUV) radiation enhancement observed in certain solar flares, which usually occurs tens of minutes to several hours after the peak of soft X-ray emission. The coronal loop system that hosts the ELP emission is often different from the main flaring arcade, and the enhanced EUV emission therein may imply an additional heating process. However, the origin of the ELP remains rather unclear. Here we present the analysis of a C1.4 flare that features such an ELP, which is also observed in microwave wavelengths by the Expanded Owens Valley Solar Array. Similar to the case of the ELP, we find a gradual microwave enhancement that occurs about 3 minutes after the main impulsive phase microwave peaks. Radio sources coincide with both foot points of the ELP loops and spectral fits on the time-varying microwave spectra demonstrate a clear deviation of the electron distribution from the Maxwellian case, which could result from injected nonthermal electrons or nonuniform heating to the footpoint plasma. We further point out that the delayed microwave enhancement suggests the presence of an additional heating process, which could be responsible for the evaporation of heated plasma that fills the ELP loops, producing the prolonged ELP emission. 

Spicules are rapidly evolving fine-scale jets of magnetized plasma in the solar chromosphere. It remains unclear how these prevalent jets originate from the solar surface and what role they play in heating the solar atmosphere. Using the Goode Solar Telescope at the Big Bear Solar Observatory, we observed spicules emerging within minutes of the appearance of opposite-polarity magnetic flux around dominant-polarity magnetic field concentrations. Data from the Solar Dynamics Observatory showed subsequent heating of the adjacent corona. The dynamic interaction of magnetic fields (likely due to magnetic reconnection) in the partially ionized lower solar atmosphere appears to generate these spicules and heat the upper solar atmosphere.