Flare Maximum Research Articles

Study of the rapid variability of a dwarf nova SS Cyg at different brightness levels

Observations of the dwarf nova SS Cyg were made in the period 2019–2021 at different brightness values (V~ 10–12m) both at the stage of falling radiation flux after the flare maximum, and in the inactive state between flares. Data were obtained in filtersRc(~8650 observations, 3 sets), andV(~50 000 points, 22 sets). The value of the system’s orbital period in 2019–2021 (Porb= 0.27408(2)d) used in this study is 0.4% less than the value obtained in 1983–1996. The time resolution between two successive measurements is 6–14 s depending on the equipment used. An extensive database of new observational data allowed us to perform a quantitative analysis of observations. Analysis of the data after taking into account orbital variability and other trends associated with changes in the system’s radiation flux during the night showed the presence of cyclic fluctuations in brightness, usually 4–10 events per orbital cycle — flickering. For most series of observations, the Lafleur-Kinman method determined such a value of the oscillation period at which convolution of observations with it showed a single wave. The obtained values of the characteristic flickering times and their amplitudes show their dependence on the average brightness level of the system. With increasing luminosity of the system, both of these quantities decreased linearly. From the component size ratios SS Cyg it was shown that the source of flickering is located in the region of interaction of the gas flow with the near-disk halo: only this region in the SS Cyg system with parameters (q,i,Rd), defined by the authors earlier, can be eclipsed at large radii disk, and is clearly visible in all other orbital phases of the system.

The White-light Superflares from Cool Stars in GWAC Triggers

M-type stars are the ones that flare most frequently, but how big their maximum flare energy can reach is still unknown. We present 163 flares from 162 individual M2 through L1-type stars that triggered the GWAC, with flare energies ranging from 1032.2 to 1036.4 erg. The flare amplitudes range from △G = 0.84 to ∼10 mag. Flare energy increases with stellar surface temperature (T eff) but both △G and equivalent duration log10(ED) seem to be independent of T eff. Combining periods detected from light curves of TESS and K2, spectra from LAMOST, the Sloan Digital Sky Survey, the 2.16 m telescope, and the Gaia DR3 data, we found that these GWAC flare stars are young. For the stars that have spectra, we found that these stars are in or very near the saturation region, and log10(LHα/Lbol) is lower for M7–L1 stars than for M2–M6 stars. We also studied the relation between GWAC flare bolometric energy E bol and stellar hemispherical area S, and found that log10Ebol (in erg) increases with increasing S (in square centimeters), and the maximum flare energy log10Ebol,max≥log10S+14.25 . For M7–L1 stars, there seem to be other factors limiting their maximum flare energies in addition to the stellar hemispherical area.

The impact of moderate solar flare activity on ionospheric response from august 5th to 7th, 2023

This study investigates the ionospheric response to a period of heightened solar flare activity from August 5th to August 7th, 2023, by analysing ground-based observations of various ionospheric parameters. The data includes detailed information on solar flare events, including their class, start time, maximum time, and end time, along with solar activity indicators such as sunspot numbers, solar radio flux, and solar zenith angles. On August 5th, multiple C-class, M-class, and an X1.63 flare were recorded, with the X-class flare being the most intense event. Ionospheric measurements revealed enhancements in electron temperatures, reaching a peak of 2104K at 6 UT, coinciding with the onset of an M1.6 flare. Additionally, a pronounced increase in total electron content (TEC) was observed, peaking at 34 TEC units at 6 UT, suggesting increased ionization due to the flare's influence. On August 6th, an M5.51 flare was the most significant event. Notably, the peak electron temperature of 2097K and the TEC maximum of 35.9 units were recorded at 6 UT, several hours before the flare's maximum phase, indicating potential preconditioning effects from the flare's preparatory stages. August 7th witnessed an X1.51 flare, along with multiple M-class flares. The peak electron temperature of 2088K and the TEC maximum of 35.3 units were observed at 7 UT, again preceding the X1.51 flare's peak, suggesting the influence of precursor effects. Throughout the observation period, the data exhibited typical diurnal patterns in ion temperatures and TEC, consistent with regular ionospheric behavior driven by solar radiation intensity variations. The study's findings provide evidence of the ionosphere's responsive nature to intense solar flare activity, with significant enhancements in electron temperatures and TEC observed during flare events. Notably, the effects were evident not only during the peak flare phases but also several hours prior, potentially due to the arrival of energetic particles or precursor electromagnetic radiation, indicating the influence of preconditioning processes. Furthermore, the data suggests that solar flares can impact the ionosphere's chemistry and dynamics, as inferred from changes in the "Ion Percentage" parameter, representing relative ionospheric compositions. Continuous monitoring and analysis of such events across different geophysical conditions are crucial for advancing the understanding of solar-terrestrial interactions and their impacts on space-based technologies, contributing to the development of improved space weather prediction and mitigation strategies.

Linear dependence of the equatorial electrojet component of X-class-triggered solar flare effects with respect to the maximum flare X-ray flux

Solar flares effects (SFE) are short geomagnetic disturbances (mainly in the horizontal component) observed during the development of solar flares. SFE are caused by current enhancements in multiple layers of the ionosphere induced by the flare ionizing radiation. Despite their origin, very few research studies have focused on the connection between the horizontal SFE amplitude and the maximum flare X-ray flux. By analyzing measurements from the magnetic station at Huancayo, Peru, located in the American sector of the equatorial electrojet (EEJ) current, we computed the horizontal SFE amplitudes triggered by X-class solar flares of Solar Cycle 24 by using a novel method. The EEJ contribution to the horizontal SFE amplitude was calculated using data from the geomagnetic observatory at Pilar, Argentina, located outside the EEJ belt. We found that the EEJ contribution to the horizontal SFE amplitude is linearly dependent on the perpendicular component of the maximum flare X-ray flux for two states of the EEJ current. We also found that the flare X-ray ionizing effect is around three times stronger in the EEJ current than in the solar quiet current, being the EEJ current the most important contributor to the horizontal SFE amplitude. In addition, our results suggest that the weak linear relationship between the pre-flare horizontal geomagnetic variation and the EEJ component of the horizontal SFE amplitude found by a previous study might be only a coincidence, instead of a real connection between both parameters. Exceptional SFE were studied separately.

The First AGILE Solar Flare Catalog

We report the Astro-rivelatore Gamma a Immagini LEggero (AGILE) observations of solar flares, detected by the onboard anticoincidence system in the 80–200 keV energy range, from 2007 May 1 to 2022 August 31. In more than 15 yr, AGILE detected 5003 X-ray, minute-lasting transients, compatible with a solar origin. A cross-correlation of these transients with the Geostationary Operational Environmental Satellites (GOES) official solar flare database allowed us to associate an intensity class (i.e., B, C, M, or X) to 3572 of them, for which we investigated the main temporal and intensity parameters. The AGILE data clearly revealed the solar activity covering the last stages of the 23rd cycle, the whole 24th cycle, and the beginning of the current 25th cycle. In order to compare our results with other space missions operating in the high-energy range, we also analyzed the public lists of solar flares reported by RHESSI and Fermi Gamma-ray Burst Monitor. This catalog reports 1424 events not contained in the GOES official data set, which, after statistical comparisons, are compatible with low-intensity, short-duration solar flares. Besides providing a further data set of solar flares detected in the hard X-ray range, this study allowed to point out two main features: a longer persistence of the decay phase in the high-energy regime, with respect to the soft X-rays, and a tendency of the flare maximum to be reached earlier in the soft X-rays with respect to the hard X-rays. Both these aspects support a two-phase acceleration mechanism of electrons in the solar atmosphere.

Multiple injections of energetic electrons associated with the flare and CME event on 9 October 2021

Context. We study the solar energetic particle (SEP) event observed on 9 October 2021 by multiple spacecraft, including Solar Orbiter. The event was associated with an M1.6 flare, a coronal mass ejection, and a shock wave. During the event, high-energy protons and electrons were recorded by multiple instruments located within a narrow longitudinal cone. Aims. An interesting aspect of the event was the multi-stage particle energisation during the flare impulsive phase and also what appears to be a separate phase of electron acceleration detected at Solar Orbiter after the flare maximum. We aim to investigate and identify the multiple sources of energetic electron acceleration. Methods. We utilised SEP electron observations from the Energetic Particle Detector (EPD) and hard X-ray (HXR) observations from the Spectrometer/Telescope for Imaging X-rays (STIX) on board Solar Orbiter, in combination with radio observations at a broad frequency range. We focused on establishing an association between the energetic electrons and the different HXR and radio emissions associated with the multiple acceleration episodes. Results. We find that the flare was able to accelerate electrons for at least 20 min during the non-thermal phase, observed in the form of five discrete HXR pulses. We also show evidence that the shock wave contributed to the electron acceleration during and after the impulsive flare phase. The detailed analysis of EPD electron data shows that there was a time difference in the release of low- and high-energy electrons, with the high-energy release delayed. Also, the observed electron anisotropy characteristics suggest a different connectivity during the two phases of acceleration.

Effects of Supra-arcade Downflows Interacting with the Postflare Arcade

Supra-arcade downflows (SADs) are dark voids descending through plasma above the postflare arcade. Although they are generally viewed as byproducts of flare reconnections in the corona, the nature of SADs is under debate. Here we investigated six distinct episodes of SADs observed in the post-maximum phase of an M-class flare of 2013 April 11. Differential emission measure analysis revealed that SAD cases occurring close to the flare maximum contain an enhanced hot plasma component at 5–7 MK whereas those occurring later exhibit a depression in hot plasma at 7–12 MK compared to the ambient supra-arcade plasma. On-disk location of the flare enabled us to examine in detail the interaction of SADs with the postflare arcade, whose effects include (1) transverse oscillations of period ∼160 s in the supra-arcade rays in the wake of voids, (2) footpoint brightening in 1700 Å whose peak is delayed by 22–46 s with respect to the SAD’s arrival at the top of the arcade, and (3) EUV intensity perturbations expanding and propagating with a speed of ∼400 km s−1. On the other hand, due to line-of-sight confusion in the optically thin corona, the ribbon enhancement following the interaction produces an illusion of plasma rebound at the top of the arcade, where the interaction fails to yield significant plasma heating. These effects indicate that the interaction mainly generates MHD waves propagating toward the surface, which may further produce quasi-periodic brightening at flare ribbons, therefore contributing to gradual phase emission from quasi-periodic EUV emission observed during the gradual phase of flares.

Analysis of Expected Skin Burns from Accepted Process Flare Heat Radiation Levels to Public Passersby

Hot flaring, even from quite high flare stacks, may result in significant heat radiation outside a facility to, e.g., public roads where random passersby may be exposed. The present study suggests a novel method for analyzing a typical flare heat radiation exposure and investigates skin burns that may be inflicted on an exposed person if a facility needs to depressurize in an emergency situation. A typical radiation field from an ignited natural gas vent was taken as the boundary condition, and these values were compared to radiation levels mentioned by the American Petroleum Institute (API 521), e.g., 1.58 kW/m2 and above. Due to facility perimeter fences along roads in larger industry areas, it was assumed that an exposed person may flee along a road rather than in the ideal direction away from the flare. It was assumed that naked skin, e.g., a bare shoulder or a bald head is exposed. The Pennes bioheat equation was numerically solved for the skin layers while the person escapes along the road. Sun radiation and convective heat exchange to the ambient air were included, and the subsequent skin injury was calculated based on the temperature development in the basal layer. Parameters affecting burn severity, such as heat radiation, solar radiation, and convective heat transfer coefficient, were analyzed. For small flares and ignited small cold vents, no skin burn would be expected for 1.58 kW/m2 or 3.16 kW/m2 maximum heat radiation at the skin surface. However, higher flare rates corresponding to, e.g., 4.0 kW/m2 maximum flare heat radiation to the skin, resulted both in higher basal layer temperatures and longer exposure time, thus increasing the damage integral significantly. It is demonstrated that the novel approach works well. In future studies, it may, e.g., be extended to cover escape through partly shielded escape routes.

Finite System-size Effects in Self-organized Criticality Systems

Abstract We explore upper limits for the largest avalanches or catastrophes in nonlinear energy dissipation systems governed by self-organized criticality. We generalize the idealized “straight” power-law size distribution and Pareto distribution functions in order to accommodate incomplete sampling, limited instrumental sensitivity, finite system-size effects, and “Black Swan” and “Dragon King” extreme events. Our findings are as follows. (i) Solar flares show no finite system-size limits up to L ≲ 200 Mm, but solar flare durations reveal an upper flare duration limit of ≲6 hr. (ii) Stellar flares observed with Kepler exhibit inertial ranges of E ≈ 1034–1037 erg, finite system-size ranges of E ≈ 1037–1038 erg, and extreme events at E ≈ (1–5) × 1038 erg. (iii) The maximum flare energies of different spectral type stars (M, K, G, F, A, giants) reveal a positive correlation with the stellar radius, which indicates a finite system-size limit imposed by the stellar surface area. Fitting our finite system-size models to terrestrial data sets (earthquakes, wildfires, city sizes, blackouts, terrorism, words, surnames, web links) yields evidence (in half of the cases) for finite system-size limits and extreme events, which can be modeled with dual power-law size distributions.

Study of Long-Duration Flares and Associated Chromospheric and Coronal Ejections in Solar Cycles 23 and 24

A statistical study of long-duration (long-duration event, LDE) flares in the soft X-ray (SXR) range for solar cycles 23 and 24 is carried out. Graphs of the dependence of the strength of LDE flares and coronal mass ejections (CMEs) on the duration of these flares are constructed. As a result, we find that a significant proportion of LDE flares is not associated with large mass CMEs. This contradicts the hypothesis that the energy required to maintain the post-eruptive phase of LDE flares is supplied by the energy of settling matter after CME eruption. However, most flares are accompanied by mini-eruptions, which may have a significance in the energy balance of LDEs. The diagram of the strength–duration of flares shows that there is a limit of energy and maximum strength of an LDE flare in the SXR range in LDE events. Apparently, this limit differs for cycles 23 and 24. This fact may indicate that there is a limit to the maximum flare energy that can be observed in a particular solar cycle.

Solar Flare Intensity Prediction With Machine Learning Models

AbstractWe develop a mixed long short‐term memory (LSTM) regression model to predict the maximum solar flare intensity within a 24‐hr time window 0–24, 6–30, 12–36, and 24–48 hr ahead of time using 6, 12, 24, and 48 hr of data (predictors) for each Helioseismic and Magnetic Imager (HMI) Active Region Patch (HARP). The model makes use of (1) the Space‐Weather HMI Active Region Patch (SHARP) parameters as predictors and (2) the exact flare intensities instead of class labels recorded in the Geostationary Operational Environmental Satellites (GOES) data set, which serves as the source of the response variables. Compared to solar flare classification, the model offers us more detailed information about the exact maximum flux level, that is, intensity, for each occurrence of a flare. We also consider classification models built on top of the regression model and obtain better results in solar flare classifications as compared to Chen et al. (2019, https://doi.org/10.1029/2019SW002214). Our results suggest that the most efficient time period for predicting the solar activity is within 24 hr before the prediction time using the SHARP parameters and the LSTM model.

Definition and construct validation of clinically relevant cutoffs on the Flare Assessment in Rheumatoid Arthritis (FLARE-RA) questionnaire

ObjectiveThe Flare Assessment in Rheumatoid Arthritis (FLARE-RA) questionnaire was devised for the detection of flares in patients with RA. We aimed to define construct validity and cut-off(s) for the FLARE-RA questionnaire. MethodsThis cross-sectional study included adult patients with prevalent RA (2010 ACR/EULAR criteria) attending outpatient rheumatology clinics in France (n = 138), Denmark (n = 253), USA (n = 75), and Argentina (n = 105). Flare occurrence over the past 3 months was assessed with the FLARE-RA questionnaire scoring from 0 (no flare) to 10 (maximum flare). The cut-offs for the FLARE-RA score were defined using the following anchor items obtained at the same encounter: (1) Patient report of flare; (2) DAS28-CRP > 3.2; (3) Change of anti-rheumatic treatment, based on the area under the receiver operating characteristic curve (AUC) and distance to (0,1). ResultsFour hundred seventy four patients with RA duration ≥2 years (mean age 58.6 years, 74.9% female) were included in the main analysis. The discrimination for the FLARE-RA cut-offs was acceptable-to-excellent: AUC for the global FLARE-RA score ranged from 0.71 to 0.92. The cut-offs for the FLARE-RA score were lower using “patient report of flare” than DAS28-CRP and “change of anti-rheumatic treatment”. Proposed FLARE-RA cut-offs for clinical detection and change of anti-rheumatic treatment are 2 and 5, respectively, for patients with RA duration 2–5 years, and 2 and 3.5, respectively, for patients with RA duration >5 years. ConclusionsProposed FLARE-RA cut-offs have acceptable discriminative capacity across the tested anchor items and are expected to aid in early recognition and timely management of RA flares.

Impact of Stellar Superflares on Planetary Habitability

High-energy radiation caused by exoplanetary space weather events from planet-hosting stars can play a crucial role in conditions promoting or destroying habitability in addition to the conventional factors. In this paper, we present the first quantitative impact evaluation system of stellar flares on the habitability factors with an emphasis on the impact of Stellar Proton Events. We derive the maximum flare energy from stellar starspot sizes and examine the impacts of flare associated ionizing radiation on CO$_2$, H$_2$, N$_2$+O$_2$ --rich atmospheres of a number of well-characterized terrestrial type exoplanets. Our simulations based on the Particle and Heavy Ion Transport code System [PHITS] suggest that the estimated ground level dose for each planet in the case of terrestrial-level atmospheric pressure (1 bar) for each exoplanet does not exceed the critical dose for complex (multi-cellular) life to persist, even for the planetary surface of Proxima Centauri b, Ross-128 b and TRAPPIST-1 e. However, when we take into account the effects of the possible maximum flares from those host stars, the estimated dose reaches fatal levels at the terrestrial lowest atmospheric depth on TRAPPIST-1 e and Ross-128 b. Large fluxes of coronal XUV radiation from active stars induces high atmospheric escape rates from close-in exoplanets suggesting that the atmospheric depth can be substantially smaller than that on the Earth. In a scenario with the atmospheric thickness of 1/10 of Earth's, the radiation dose from close-in planets including Proxima Centauri b and TRAPPIST-1 e reach near fatal dose levels with annual frequency of flare occurrence from their hoststars.

An Unusually Powerful Water-Maser Flare in the Galactic Source W49N

The most powerful flare ever registered in the Galactic water-maser source W49N has been detected in long-term monitoring data in the 616–523 transition with line frequency f = 22.235 GHz carried out on the 22-m Simeiz, 32-m Torun, 100-m Effelsberg, and 32-m Medicina radio telescopes, beginning in September 2017 and continuing in 2018. Some stages of the flare were monitored daily. Detailed variations of the source spectral flux density with time have been obtained. At the flare maximum, the flux exceeded P ≈ 8 × 104 Jy, and this was record highest flux registered over the entire history of observations of this source. Important conclusions related to details of the mechanism for the H2O line emission have been drawn. An exponential increase in the flare flux density was detected during both the rise and decline of the flare. The data obtained indicate that the maser is unsaturated, and remained in this state up to the maximum observed flux densities. Additional support for the idea that the maser is unsaturated is the shape of the dependence of the line width on the flux. The characteristics of the variations of the spectral flux density are probably associated with a sharp increase in the density of the medium and the photon flux that led to an increase in the temperature from an initial level of 10–40 K to hundreds of Kelvins. Interferometric maps of the object during the increase in the spectral flux density of the flare have been obtained. A possible mechanism for the primary energy release in W49N is considered.

Optimization of flare management in patients with rheumatoid arthritis: results of a randomized controlled trial.

To evaluate the effect of a flare management intervention guided by non-physician providers versus usual care between rheumatology visits on flare occurrence and rheumatoid arthritis (RA) disease activity. Adult patients with established RA (per 2010 ACR criteria, n = 150) were randomized to the intervention arm (n = 75) versus usual care (n = 75). The Flare Assessment in Rheumatoid Arthritis (FLARE-RA) questionnaire was administered monthly during 24months to all patients in the intervention arm to assess flare status. Telephone nurse-led counseling or an expedited visit with a rheumatology provider was offered to patients in the intervention arm who indicated they were in flare. Patients in the intervention arm completed a median of 8.5 (range 1-24) questionnaires. RA flare was reported on 122 (19%) of these questionnaires; average FLARE-RA score, 4.72 on 0 (no flare) to 10 (maximum flare) scale. Patients preferred an expedited clinic visit with a rheumatology provider during 39 (32%) of flares. The majority of patients preferred to self-manage their flare (76, 62%); some patients received nursing advice on flare management over the phone (7, 6%). There were no differences in RA flare by OMERACT9 definition, DAS28-CRP, CDAI, SDAI, anti-rheumatic treatment change by rheumatology provider, or remission by CDAI between the study arms over 24-month follow-up. The flare management intervention did not have any major effect on flare occurrence or RA disease activity metrics over the 24-month follow-up. The majority of patients in the intervention arm preferred self-management to an expedited visit with their rheumatology provider. ClinicalTrials.gov Identifier: NCT02382783 ( https://clinicaltrials.gov/ct2/show/NCT02382783 ) Key Points • The flare management intervention had no effect on rheumatoid arthritis (RA) disease activity. • Patients preferred self-management of their RA flares to expedited rheumatology provider visits.

THE ANTIOXIDANT IN THE COMPOSITIONOF ANTIPARASITIC PASTE FOR HORSES

The long-running parasitic process adversely affects the viability of the antioxidant defense system, which is reflected in an increase in the onset of the maximum signal reduction and a decrease in the AOA. For the treatment of equine helminth infections, drugs are needed that combine high anthelmintic efficacy with a simultaneous immunostimulating effect. The use of antioxidants in the composition of antiparasitic drugs increases the effectiveness of deworming. The use of the antiparasitic drug alezan containing ivermectin, praziquantel and antioxidant santohin in helminthiases of horses once at the rate of 1 g of paste per 100 kg of animal weight in a therapeutic dose ensured the complete elimination of worms from the host's body by the 10th day of research. The drug is used for therapeutic and prophylactic purposes. Significant changes in the content of total protein, alpha- and gamma-globulins, AlAt and AsAt by the 28th day of research indicate that there is no negative effect of deworming. Information was obtained on the positive effect of the antiparasitic paste with antioxidant on the light sum (S) and maximum flare (Imax), which is characterized by a decrease in the level of free radical lipid oxidation with a decrease in the light sum of radicals by 14.6% and an increase in the antioxidant activity of horse serum by 26.5% on the 7th day. By the 14th day, the radical sum of radicals decreased by 16.9%, the maximum luminescence intensity – by 34.3%, and on the 28th day the light sum index was 26.73, which corresponded to the standard data. With chronic parasitic invasion, a low AOA was observed.

Variability of the Blazar J1504+1029 on Timescales from Hours to Years

The results of observations of the blazar J1504+1029 (PKS 1502+106, OR 103), obtained in 2000–2018 on the RATAN-600 radio telescope of the Special Astrophysical Observatory at 2.3, 3.9 (4.7), 7.7 (8.2), 11.2, and 21.7 GHz and on the 32-m Zelenchuk and Badary radio telescopes of the Quasar-KVO complex of the Institute of Applied Astronomy of the Russian Academy of Sciences at 5.05 and 8.63 GHz are presented. The long-term variability is studied, as well as variability on time scales from several days to several weeks and intraday variability (IDV). The long-term light curves are correlated at all frequencies and show continuous activity, against which three flares with their maxima in 2002, 2009, and 2018 are distinguished. The time scale for variability of the flare in 2009 is τvar ≈ 1 year. At 21.7 GHz, the linear size of the emitting region is R ≤ 0.3 pc, its angular size is θ ≤ 0.05 mas, its brightness temperature is Tb ≥ 2 × 1014 K, and the Doppler factor is δ ≥ 5.8. The flare with its maximum in 2018 has a long rising branch at 21.7 GHz: τvar = 3.2 years, linear size R ≤ 1.1 pc, angular size θ ≤ 0.17 μas, brightness temperature Tb ≥ 2.2 × 1012 K, and Doppler factor δ ≥ 2.8. Among eleven sets of daily observations of the source over 75–120 days in 2000–2017, variability was detected in eight data sets at two to four frequencies with characteristic time scales of 4–30 days. In seven data sets, the variability is due to one to three cyclic processes with characteristic time scales τacf = 4−30d. The spectral indices of the variable components in different years vary from αvar = −1.6 to +1.8. In at least four data sets, the variability is due to processes in the source itself. In this case, at 21.7 GHz, the apparent linear size of the emitting region is ≤4000 AU, the angular size is θ ≤ 3.5 μas, the brightness temperature is Tb ≥ 3 × 1014 K, and the Doppler factor is δ ≥ 14. In the 2004 data set, the variability has an “ anti-flare” form, with the flux density of the variable component falling at high frequencies. Thirty-six successful sessions were conducted on the 32-m telescopes at 8.63 GHz, and 16 at 5.05 GHz. IDV was detected in 17 sessions at 8.63 GHz and in three sessions at 5.05 GHz, with the IDV being detected mainly near flare maxima.

Correlations between the CME acceleration, other CME parameters and flare energy

While the Coronal Mass Ejections (CMEs) without associated flares are known to accelerate and decelerate being moderated by the Lorentz force, gravity and the drag force due to solar wind, the flare association is known to prolong the acceleration. However, with or without the flare association, a significant proportion of slow CMEs decelerate and a similar proportion of fast CMEs accelerate. In the case of accelerating CMEs, various parameters of CMEs such as the mass, angular width etc. show good correlation and this improves with flare association. When the flares and CMEs are associated, there is apparently a division of energy between the flares and the CMEs. It is also known that the magnetic flux spanned by the flare arcade and ribbons after flare maximum, roughly equals the magnetic flux content of the CME and their ratio could be between one and two. The magnetic flux content of the CME can be estimated from the final angular width of the CME. Hence, we suggest that the CMEs experience net acceleration when the different parameters of CMEs such as angular width, mass etc. are correlated and when the CME parameters are correlated with flare duration and peak flux. The absence of the same may lead to CMEs experience net deceleration.

Objective Methods for Breast Sensibility Testing.

The breast and the factors that affect the sensitivity of the nipple-areola complex have been a significant subject of study in recent years. The main purpose of this study was to provide an objective assessment of the effect of volumetric differences on nipple-areola complex sensitivity. Data were collected examining the right breast of 34 female volunteers. The mechanosensitive Aβ-fiber and mechanoinsensitive C-fiber function of the nipple-areola complex was assessed after mechanical and chemical stimulation, respectively. Flare responses were elicited chemically by the application of histamine by means of iontophoresis and recorded by laser Doppler imaging. The correlation of the maximum flare area responses with the breast volume and nipple-areola complex and the response from the von Frey fiber test was estimated using linear regression analysis. Nipple-areola complex area increased with breast volume and, similarly, the area of histamine-induced axon reflex flare response follows the larger nipple-areola complex. However, a larger nipple-areola complex correlated with higher local mechanical thresholds. Higher mechanical thresholds were linked to smaller axon reflex area, suggesting combined small- and thick-fiber neuropathy. Objective small-fiber assessment using laser Doppler imaging and subjective mechanical threshold tests were used successfully to quantify function of Aβ and C fibers in the nipple-areola complex. Increased breast volume was linked to larger nipples, but also to impairment of Aβ and C fibers. Sensory testing can be incorporated into preoperative and postoperative management of patients undergoing breast operations to assess changes of neuronal function of the nipple-areola complex after surgery.

Geometry, Kinematics, and Heliospheric Impact of a Large CME-driven Shock in 2017 September

Abstract A powerful coronal mass ejection (CME) occurred on 2017 September 10 near the end of the declining phase of the historically weak solar cycle 24. We obtain new insights concerning the geometry and kinematics of CME-driven shocks in relation to their heliospheric impacts from the optimal, multispacecraft observations of the eruption. The shock, which together with the CME driver can be tracked from the early stage to the outer corona, shows a large oblate structure produced by the vast expansion of the ejecta. The expansion speeds of the shock along the radial and lateral directions are much larger than the translational speed of the shock center, all of which increase during the flare rise phase, peak slightly after the flare maximum and then decrease. The near simultaneous arrival of the CME-driven shock at the Earth and Mars, which are separated by 156.°6 in longitude, is consistent with the dominance of expansion over translation observed near the Sun. The shock decayed and failed to reach STEREO A around the backward direction. Comparison between ENLIL MHD simulations and the multipoint in situ measurements indicates that the shock expansion near the Sun is crucial for determining the arrival or nonarrival and space weather impact at certain heliospheric locations. The large shock geometry and kinematics have to be taken into account and properly treated for accurate predictions of the arrival time and space weather impact of CMEs.