Results 31 to 40 of about 465,086 (299)

Variable Stars [PDF]

open access: yes, 2021
تتطرق هذه المقالة إلى أجرام سماوية شهيرة جداً في علم فيزياء الفلك تدعى بالنجوم المتغيرة (variable stars). تتضمن مجموعة النجوم المتغيرة فيزيائيا نوعين رئيسيين وهما نجوم متغيرة بانتظام ونجوم غير متغيرة بانتظام.
معلا, محمد
core   +1 more source

Magnetic activities and parameters of 43 flare stars in the GWAC archive [PDF]

open access: yes, 2022
In the archive of the Ground Wide Angle Camera (GWAC), we found 43 white light flares from 43 stars, among which, three are sympathetic or homologous flares, and one of them also has a quasi-periodic pulsation with a period of $13.0\pm1.5$ minutes. Among
Huang, Lei   +21 more
core   +1 more source

Spots and Flares in Hot Main Sequence Stars Observed by Kepler, K2, and TESS

open access: yesFrontiers in Astronomy and Space Sciences, 2021
About 22,000 Kepler stars, 7,000 K2 stars, and nearly 60,000 TESS stars from sectors 1–24 have been classified according to variability type. A large proportion of stars of all spectral types appear to have periods in their light curves consistent with ...
Luis A. Balona
doaj   +1 more source

Optical and X-ray studies of newly discovered flare stars

open access: yes
Results are presented demonstrating that selection of dMe flare stars from their EU V/optical flux ratio revealed some of the most active members from the ROSAT Wide Field Camera (WFC) and EUVE all-sky surveys.
Ball, William Northey
core   +4 more sources

Starquakes on Flare stars

open access: yes, 2023
Flare Stars has been a subject of extending research for many decades at the Stefanion Observatory. Apart of the spectacular flaring phenomena, the results of the analysis of the one colour (B) observations of the Stefanion Observatory at any stage of their activity (quiescence, weak flares, strong flares),indicate that: (1) Transient high frequency ...
Contadakis, Michael   +3 more
openaire   +1 more source

Flares in A-type stars? [PDF]

open access: yesProceedings of the International Astronomical Union, 2015
AbstractStellar flares are known to originate from magnetic reconnection in the atmospheres of late–type stars or through radiatively driven wind instabilities in early–type stars. Situated right between these two groups, the A–type stars are not expected to support either of the two mechanisms.
May G. Pedersen   +2 more
openaire   +1 more source

Properties of Flare Quasiperiodic Pulsations Based on a New TESS Flare Catalog

open access: yesThe Astrophysical Journal Supplement Series
Stellar flares are important indicators of stellar magnetic activity and have been widely studied. Detailed studies of flares have raised new questions. For example, the quasiperiodic pulsation (QPP) phenomenon in flares challenges standard flare models,
Yinpeng Wang   +4 more
doaj   +1 more source

Artificial Intelligence–Based Online Symptom Assessment Tools for Systemic Lupus Erythematosus Diagnosis: Patient Perspectives

open access: yesArthritis Care &Research, EarlyView.
Objective The objective of this article is to identify perceptions of patients with systemic lupus erythematosus (SLE) regarding artificial intelligence (AI)–based online symptom assessment tools, and the potential of these tools to address diagnostic barriers.
Olivia A. Stein   +7 more
wiley   +1 more source

Magnetic Activity of TESS Objects Observed in the LAMOST Medium-resolution Spectral Survey

open access: yesThe Astrophysical Journal Supplement Series
A combination of spectroscopic and photometric observations provides an excellent data sample for studying stellar chromospheric activity. We have combined LAMOST medium-resolution spectra with TESS 2 minute light curves and extracted over 530,000 ...
Tianhao Su   +8 more
doaj   +1 more source

FLARES ON A Bp STAR [PDF]

open access: yesThe Astrophysical Journal, 2009
Two large X-ray flares have been reported from the direction of a magnetic B2p star (σ Ori E). Sanz-Forcada et al. have suggested that the flares did not occur on the B2p star but on a companion of late spectral type. A star which is a candidate for a late-type flare star near σ Ori E has recently been identified by Bouy et al.
openaire   +1 more source

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