Photometric space missions like Kepler and TESS have revealed unprecedented statistics of stellar flares, including the frequent detection of highly energetic superflares. Spectroscopic characterization of flares and especially superflares, however, is still not as commonly available. In contrast to broad-band photometry, spectroscopic data can give more insights into the physical parameters of flares, as well as allowing to identify possibly accompanying CMEs. In this context, we monitored the young planet-hosting flare star AU Mic for about 60 partial nights (>160 hours) between 2022 and 2023 spectroscopically with the ESO 1.52m telescope hosted by the PLATOSpec consortium. Here, we report on the search for signatures of flares and CMEs in these data, including the partial observation of a possible extreme superflare.

In this study, we examine the social media response statistics to a recent astrobiology headline about the discovery of phosphorus on Venus, which led to a media outbreak of ‘Life on Venus?’ claims. We estimate its impact scale by comparing it with other events.

Solar type-II radio bursts are coherent plasma emissions arising from magnetohydrodynamic shocks produced by either coronal mass ejections (CMEs) or flares. Type-II bursts sometimes show split-band emissions in the dynamic spectrum. When these split-band emissions come from regions just upstream and downstream of the shock, type-II band-splitting can be used as an important tool for estimating magnetic fields at the shock front. Earlier studies have shown that only ∼20% of the type-IIs show morphologically similar split-bands. Imaging studies can unambiguously identify such instances, though they remain very rare. Here we suggest a useful approach to augment dynamic spectra based studies by also examining the Gradient Dynamic Spectra (GraDS) of type-II emission. We also verified the conclusions of this approach against those from an imaging study.

Coronal mass ejections (CMEs) are large-scale ejections of magnetized plasma from the Sun and are associated with the most extreme space weather events. The southward component of CME magnetic fields (CME-Bz) is one of the crucial parameters determining its geoeffectiveness. Recent studies have shown that CMEs evolve significantly in the innermost part of the heliosphere (∼ 20 − 90 R⊙), and relying on extrapolations from low coronal heights can lead to wrong predictions of CME-Bz in the vicinity of Earth. Hence, measuring CME magnetic fields at these heights is important to improve CME-Bz prediction. A promising method to measure the CME-entrained magnetic field in the larger coronal heights and the innermost heliosphere is by measuring the changes in Faraday rotation (FR) of linearly polarized emission from back-ground radio sources as their line-of-sight crosses the CME plasma. Here, we present the current preparation of new-generation ground-based radio telescopes for this purpose.

It was found that the cluster NGC 1977, located in the region of Orion’s Sword, in past epochs approached in space the star TOI-2796, which has a planetary system. It should be noted that in the vicinity of NGC 1977, the James Webb Space Telescope observed more than 500 free planets and free binary planets. Numerical calculations of the orbit around the Galactic Center were carried out. It is shown that these objects approached at a distance of ∼7.8 pc about ∼4.4 million years ago. This approach could have a gravitational effect on the Oort cloud analogue TOI-2796, leading to a change in the orbital elements of small bodies. It is important to note that the observed effect could be the loss of objects from the TOI-2796 planetary system into interstellar space.

AB Doradus is a young, active solar-type star whose large-scale coronal magnetic field is 100–1000 times more intense than that of the Sun. Magnetic fields of such magnitude are believed to prevent stellar coronal mass ejections (CMEs) from erupting. It is, therefore, surprising that coronal dimming was recently observed in AB Doradus, as coronal dimming is typically associated with CMEs. We propose that CMEs in AB Doradus occur in high-latitude regions where parts of the coronal magnetic field may be open. We modelled the global coronal magnetohydrodynamics for twenty-one CMEs, injecting CMEs into high-latitude regions with both closed and open magnetic field configurations. Our models demonstrate that CMEs in areas with open magnetic fields are not obstructed by the overlying magnetic field, suggesting that magnetic confinement of CMEs may be less common in young solar-type stars than previously assumed. For full details of this study, we direct the reader to Strickert et al. (2024).

As the commercial space industry advances, the number of artificial objects orbiting the Earth rises exponentially. To categorize the reflectivity of bright Low Earth Orbit (LEO) objects, a number of spectroscopic observations of such objects was performed in collaboration with the Astronomical Institute of the University in Bern, Switzerland. Supported by laboratory measurements of various aerospace materials, spectra of space objects were analyzed to search for correlations with material samples. On top of that, near-Earth object 2020 SO originally discovered as asteroid was later identified as Surveyor 2 rocket debris. Spectroscopic observation of this object was conducted with the OSIRIS camera-spectrograph at the 10.4m Gran Telescopio Canarias (GTC) located in La Palma (Spain). Spectrum of this object is compared with spectra of upper stage rockets observed by the ZimMain telescope to investigate correlations within their material properties and search for signs of space weathering.

This work provides a detailed walk through the design, construction, and operation of a DIY monitoring station, emphasising its affordability, accessibility, and ease of use. The station leverages readily available components, including software defined radio (SDR) receivers and a Raspberry Pi. These tools allow for constant 24/7 monitoring and automatic storage of band usage and the detection of Doppler-shifts in the satellite beacons, providing valuable data for analysis.

Using this DIY setup can lead to indications of power levels and beam shapes of the Starlink satellites and user link strategy. Additionally, an experimental interferometer mode is being implemented, further expanding the capabilities of this home-based monitoring station with direct positional information.

The discovery of phosphine in Venus’s atmosphere provides lessons for the search for life. The detection has survived all challenges and has acquired independent support from archival data from PVP. The presence of phosphine in Venus’ oxidising environment is perplexing, and comprehensive studies rule out all known abiotic sources. More data is needed to understand the origin of phosphine, leading to JCMT-Venus, a long term atmospheric monitoring programme. This can find how phosphine varies in relation to other species providing clues to its origin. We present the latest JCMT-Venus results. The discovery and subsequent papers were explicit that they did not constitute evidence for life, only of phosphine. Media and public reaction to the discovery and its implications provide lessons for future life searches, as does the reaction of the scientific community. How this was handled by the team, media, and general public will be reviewed.

We analyses occurrence of DH type II solar radio bursts spanning over solar cycles 23-25 during which a total of 590 DH type II bursts are reported with confirmed 568 and 462 cases of associated CME and flares, respectively. We find short-term yet important differences in DH type II activity when the data is examined in terms of event counts and their durations, e.g., temporal shift in the peak activity during cycle 24 and variation in the growth rate of the activity level during cycle 25. For an in-depth exploration, DH type II bursts are classified in 3 categories based on their end-frequencies: Low-, Medium-, and High- Frequency Groups (LFG, MFG, and HFG, respectively). The HFG category is the most populous (≈47%) while the LFG category occupy about a quarter of the events (≈24%). The LFG events show a clear inclination toward fastest CMEs and X-class flares with a quarter of events exhibiting end frequency below 50 MHz.

Eruptive and confined flares are distinguished by their coronal mass ejection (CME) association. From 1996 January to 2023 December, we found 1,748 flares with definite CME association (eruptive flares) and 7,288 flares that lacked CMEs (confined flares) using the coronagraph observations by SOHO/LASCO and STEREO/SECCHI. Flare temperatures, which are measured from the GOES short/long wavelength ratio, increase with the peak X-ray intensity. Average maximum temperature is 10 MK at C3.0 and 24 MK at X10 level. [Kay et∼al., 2003] examined a total of 69 eruptive and confined flares and found that eruptive flares tend to have lower temperatures than the confined ones. By analyzing a 100 times larger data set, we confirmed that result and found that, for a given X-ray flare intensity, the average maximum temperature of eruptive flares is approximately 0.9 MK cooler than that of the confined ones.

On the Sun, the energetic, erupting phenomena of flares and coronal mass ejections (CMEs) often occur together. While space-based photometry has revealed frequent white-light flares for vast numbers of stars, only a handful of coronal mass ejections have been detected. Space-based photometry reveals the timing and detailed structure of flares. To detect CME signatures, however, optical spectroscopy is essential, as the ejected plasma can be detected by Doppler-shifted emission bumps in the Balmer-regions. We present a dedicated ground-based multi-object spectroscopic observations of the young, nearby Praesepe (600 Myr) and Pleiades (135 Myr) clusters to detect CMEs and flares parallel with the observations of Praesepe by the TESS satellite. During the 10 days of overlapping observations, we did not find any obvious signs of CMEs or flares in the Hα region.

This study examines the potential impact of the discovery of extraterrestrial intelligent life (ETI) on Catholic theology. The investigation addresses whether the existence of ETIs would challenge core theological principles, particularly the doctrine of Redemption. The study concludes that the discovery of ETIs would not disrupt the foundational tenets of Catholic faith, which is centered on Jesus Christ. The Church has not made any official statements regarding the theological implications of ETIs, reflecting the current speculative nature of their existence. However, the Vatican Observatory is actively involved in research related to potential life-hosting stars, indicating a scientific interest in the topic.

For several decades we have been performing photometric monitoring of some of the star formation regions using the telescopes in Rozhen Observatory. We consider that the study of photometric variability of pre-main sequence (PMS) stars is of great importance in understanding stellar evolution. A number of young stellar objects show brightness variability with large amplitudes that can be registered with small and medium-sized telescopes. But in recent years, bright traces of satellites have increasingly appeared in our CCD images. So far they are not much of a problem since most of our objects and the standard stars around them are point sources of small apparent size. But in the future, the possible increase in the number and brightness of satellite tracks may affect the quality of the photometric data we receive.

Bright satellite streaks present challenges for astronomy. No streak detection is prefect and the profile of the streak flux varies along the streak. Using Rubin Observatory’s LSST as an example, we undertake full simulations and outline the challenges and the impact on science.

The Pampilhosa da Serra Space Observatory (PASO) is located in the centre of the continental Portuguese territory, in the heart of a dark-sky destination certified by the Starlight Foundation (Aldeias do Xisto) and has been an instrumental asset to advance science, education and astrotourism certifications. PASO hosts astronomy and Space Situational Awareness (SSA) activities including a node of the Portuguese Space Surveillance & Tracking (SST) infrastructure network, such as a space radar currently in the test phase using the GEM radiotelescope, a double Wide Field of View (WFOV) Telescope system, and a European Union SST optical sensor telescope. These instruments allow surveillance of satellite and space debris in LEO, MEO and GEO orbits. The WFOV telescope offers spectroscopy capabilities enabling light curve analysis and cosmic sources monitoring. Instruments for space weather are being considered for installation to monitor solar activities and expand the range of SSA services.

Carbon-14 (14C) analysis of tree rings has revealed multiple rapid increases in 14C (14C spikes) during the Holocene, e.g., in ca. 774 CE, 993 CE, 660 BCE, and 7176 BCE. These 14C spikes have been replicated by several tree-ring 14C records and other cosmogenic nuclide records, such as 10Be and 36Cl from ice cores. These events are considered to have been caused by extreme solar energetic particle (SEP) events, with the scale of the SEP events estimated to be several dozen times larger than the largest SEP event detected in modern observations. As such, studies on past SEP events using cosmogenic nuclides have advanced in recent years; however, several issues regarding such events remain unknown. This paper reviewed recent studies on the following topics: 1) further exploration of extreme SEP events over the long term, and 2) exploration of intermediate-sized SEP events between those detected by modern observations and the extreme SEP events detected by cosmogenic nuclides. Future research directions for these topics were also discussed.

Recent research has revealed that small-scale coronal mass ejections (CMEs) in the quiet Sun exhibit similarities in their formation mechanisms and eruption characteristics when compared to large-scale solar eruptions. The occurence of small-scale CMEs increases exponentially as their size decreases. Thus, the role of small-scale CMEs in solar wind formation should not be underestimated. Can small-scale eruptions in the quiet Sun propagate into the higher solar corona? I analyze a typical small-scale eruption in the quiet Sun and reconstruct a flux-rope (FR) structure. My results indicate that torus instability of the FR can be triggered at a relatively low critical height of : 8 Mm. This suggests that the quiet Sun’s FRs can easily overcome the confinement of the low coronal magnetic field and enter the higher corona. However, further investigation is still needed to determine if the large-scale coronal mangetic fields above constrain these small-scale eruptions.