Results 21 to 30 of about 1,348 (287)

Solar and Stellar Flares: Frequency, Active Regions, and Stellar Dynamo

The Astrophysical Journal, 2022
Abstract We demonstrate that for weak flares the dependence of their frequency occurrence on spottedness can be rather weak. The fact is that such flares can occur in both small and large active regions. At the same time, powerful large flares of classes M and X occur much more often in large active regions. In energy estimates, the mean
M. M. Katsova, V. N. Obridko, D. D. Sokoloff, I. M. Livshits   +3 more
openaire   +2 more sources

A 7 Day Multiwavelength Flare Campaign on AU Mic. I. High-time-resolution Light Curves and the Thermal Empirical Neupert Effect

The Astrophysical Journal, 2023
We present light curves and flares from a 7 day, multiwavelength observational campaign of AU Mic, a young and active dM1e star with exoplanets and a debris disk. We report on 73 unique flares between the X-ray to optical data.
Isaiah I. Tristan, Yuta Notsu, Adam F. Kowalski, Alexander Brown, John P. Wisniewski, Rachel A. Osten, Eliot H. Vrijmoet, Graeme L. White, Brad D. Carter, Carol A. Grady, Todd J. Henry, Rodrigo H. Hinojosa, Jamie R. Lomax, James E. Neff, Leonardo A. Paredes, Jack Soutter   +15 more
doaj   +1 more source

Power-law Distribution of Solar Cycle–modulated Coronal Jets

The Astrophysical Journal Supplement Series, 2023
Power-law distributions have been studied as a significant characteristic of nonlinear dissipative systems. Since discovering the power-law distribution of solar flares that was later extended to nanoflares and stellar flares, it has been widely accepted
Jiajia Liu, Anchuan Song, David B. Jess, Jie Zhang, Mihalis Mathioudakis, Szabolcs Soós, Francis P. Keenan, Yuming Wang, Robertus Erdélyi   +8 more
doaj   +1 more source

Stellar Parameters and Spectroscopic Properties of TESS Objects Observed in the LAMOST Low- and Medium-resolution Spectral Survey

The Astrophysical Journal Supplement Series, 2022
Stellar parameters and magnetic activity are important for the understanding of stellar physics and dynamo theory. We have used LAMOST spectroscopic surveys to study stellar parameters and magnetic activity properties of TESS objects.
Li-yun Zhang, Tianhao Su, Prabhakar Misra, Xianming L. Han, Gang Meng, Qingfeng Pi, Jiawei Yang   +6 more
doaj   +1 more source

Starspot Mapping with Adaptive Parallel Tempering. II. Application to TESS Data for M-dwarf Flare Stars AU Microscopii, YZ Canis Minoris, and EV Lacertae

The Astrophysical Journal, 2023
Starspots and stellar flares are indicators of stellar magnetic activity. The magnetic energy stored around spots is thought to be the origin of flares, but the connection is not completely understood.
Kai Ikuta, Kosuke Namekata, Yuta Notsu, Hiroyuki Maehara, Soshi Okamoto, Satoshi Honda, Daisaku Nogami, Kazunari Shibata   +7 more
doaj   +1 more source

Models for stellar flares

The Astrophysical Journal, 1982
We study the response of certain spectral signatures of stellar flares (such as Balmer line profiles and the broad-band continuum) to changes in atmospheric structure which might result from physical processes akin to those thought to occur in solar flares.
L. E. Cram, D. T. Woods
openaire   +1 more source

Constraints on Stellar Flare Energy Ratios in the NUV and Optical from a Multiwavelength Study of GALEX and Kepler Flare Stars

The Astrophysical Journal, 2023
We present a multiwavelength study of stellar flares on primarily G-type stars using overlapping time domain surveys in the near-ultraviolet (NUV) and optical regimes. The NUV (the Galaxy Evolution Explorer; GALEX) and optical (Kepler) wavelength domains
C. E. Brasseur, Rachel A. Osten, Isaiah I. Tristan, Adam F. Kowalski   +3 more
doaj   +1 more source

Properties of PSR J1023+0038 Based on Kepler, TESS, and FAST

The Astrophysical Journal, 2023
The pulsar system PSR J1023+0038 is a very interesting binary with radio millisecond pulsar and low-mass X-ray binary transitions, which depend on the stellar accretion process. We have used Kepler light curves with 1 minute cadence and TESS light curves
Li-yun Zhang, Zilu Yang, Baoda Li, Tianhao Su, Prabhakar Misra, Xianming L. Han, Liu Long   +6 more
doaj   +1 more source

Reduction in Renal Relapse and Preservation of Long‐Term Kidney Function After Lupus Low Disease Activity in Patients With Lupus Nephritis

Arthritis Care &Research, EarlyView.
Objective Lupus low disease activity state (LLDAS) is a validated treatment target in systemic lupus erythematosus (SLE), but limited studies have explored the role of LLDAS in lupus nephritis (LN). This study aims to investigate the frequency and predictors of LLDAS attainment and its benefit on LN relapse and renal function preservation in patients ...
Chak Kwan Cheung, Desmond Y. H. Yap, Ka Lai Lee, Philip H. Li, Iris Y. K. Tang, Chak Sing Lau, Shirley C. W. Chan   +6 more
wiley   +1 more source

Statistics of Solar White-light Flares. I. Optimization and Application of Identification Methods

The Astrophysical Journal
White-light flares (WLFs) are energetic activity in the stellar atmosphere. However, observed solar WLFs are relatively rare compared to stellar WLFs or solar flares observed at other wavelengths, which limits our further understanding of solar/stellar ...
Yingjie Cai, Yijun Hou, Ting Li, Jifeng Liu   +3 more
doaj   +1 more source