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Related papers: Spots and flares in hot main sequence stars

200 papers

Visual classification of the variability classes of over 120,000 Kepler, K2 and TESS stars is presented. The sample is mainly based on stars with known spectral types. Since variability classification often requires the location of the star…

Solar and Stellar Astrophysics · Physics 2023-08-16 Luis A. Balona

Stellar rotation is a fundamental observable that drives different aspects of stellar and planetary evolution. In this work, we present an unprecedented manifold analysis of 160 B-type stars with light curves collected by the TESS space…

Stars which are rapidly rotating are expected to show high levels of activity according to the activity-rotation relation. However, previous TESS studies have found Ultra Fast Rotating (UFR) M dwarfs with periods less than one day…

Solar and Stellar Astrophysics · Physics 2022-03-02 Lauren Doyle , Stefano Bagnulo , Gavin Ramsay , Gerry Doyle , Pasi Hakala

We have searched for short periodicities in the light curves of stars with $T_{\rm eff}$ cooler than 4000 K made from 2-minute cadence data obtained in TESS sectors 1 and 2. Herein we report the discovery of 10 rapidly rotating M-dwarfs…

We characterize the magnetic activity of M dwarfs to provide the planet community with information on the energy input from the star; in particular, in addition to the frequency of optical flares directly observed with TESS, we aim at…

Solar and Stellar Astrophysics · Physics 2022-09-14 B. Stelzer , M. Bogner , E. Magaudda , St. Raetz

The light curves of 252 B-star candidates in the Kepler data base are analyzed in a similar fashion to that done by Balona et al. (2011) to further characterize B star variability, increase the sample of variable B stars for future study,…

Solar and Stellar Astrophysics · Physics 2012-03-19 Bernard J. McNamara , Jason Jackiewicz , Jean McKeever

We study 119 B stars located in the Scorpius-Centaurus Association using data from NASA's TESS Mission. We see pulsations in 81 stars (68%) across the full range of effective temperatures. In particular, we confirm previous reports of…

Solar and Stellar Astrophysics · Physics 2026-02-18 Awshesh N. Sharma , Timothy R. Bedding , Hideyuki Saio , Timothy R. White

The study is devoted to search for flare stars among confirmed members of Galactic open clusters using high-cadence photometry from {\it TESS} mission. We analyzed 957 high-cadence light curves of members from 136 open clusters. As a…

Solar and Stellar Astrophysics · Physics 2021-02-10 O. Maryeva , K. Bicz , C. Xia , M. Baratella , P. Čechvala , K. Vida

We present the results of a search for stellar flares in the first data release from the Next Generation Transit Survey (NGTS). We have found 610 flares from 339 stars, with spectral types between F8 and M6, the majority of which belong to…

We apply multi-algorithm machine learning models to TESS 2-minute survey data from Sectors 1-72 to identify stellar flares. Models trained with Deep Neural Network, Random Forest, and XGBoost algorithms, respectively, utilized four flare…

Solar and Stellar Astrophysics · Physics 2024-10-24 Chia-Lung Lin , Daniel Apai , Mark S. Giampapa , Wing-Huen Ip

This work is dedicated to a search for new pulsating hot subdwarfs in TESS photometric data which could have been missed in previous searches. By matching catalogues of hot subdwarfs with TESS targets and using luminosities from Gaia…

Solar and Stellar Astrophysics · Physics 2022-07-13 J. Krzesinski , L. A. Balona

The goal of our study is to provide a reliable classification of variability of A-F stars brighter than 11 mag located in the northern TESS continuous viewing zone. We also aim at thorough discussion about issues in the classification…

Photometric space missions like Kepler and TESS continuously discover new exoplanets and advance the search for a second habitable world. The light curves recorded by these telescopes also reveal signs of magnetic activity, such as star…

Solar and Stellar Astrophysics · Physics 2021-11-16 Mirjam Bogner , Beate Stelzer , Stefanie Raetz

The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds of A-F type stars. We present a first general characterization of the pulsational behaviour of A-F type stars as observed in the…

During the last two years we have received long time-series photometric observations of bright (V mag < 8) main-sequence A- and B-type stars observed by the NASA TESS spacecraft and the Austria-Poland-Canada BRITE satellites. Using TESS…

We present an overview of K2 short cadence observations for 34 M dwarfs observed in Campaigns 1 - 9 which have spectral types between M0 - L1. All of the stars in our sample showed flares with the most energetic reaching $3\times10^{34}$…

Solar and Stellar Astrophysics · Physics 2019-03-06 Lauren Doyle , Gavin Ramsay , John G. Doyle

Light curves of 57 classical Be stars in TESS sectors 1 - 15 are examined. In most Be stars, the periodogram shows groups at a fundamental and one or more harmonics, which we attribute to rotation. In about 40 percent of the stars, the…

Solar and Stellar Astrophysics · Physics 2020-02-19 Luis A. Balona , Dogus Ozuyar

We report on the detection of pulsations of three pulsating subdwarf B stars observed by the TESS satellite and our results of mode identification in these stars based on an asymptotic period relation. SB 459 (TIC 067584818), SB 815 (TIC…

We investigate the light variations of 15 Am stars using four years of high-precision photometry from the Kepler spacecraft and an additional 14 Am stars from the K2 Campaign 0 field. We find that most of the Am stars in the Kepler field…

Solar and Stellar Astrophysics · Physics 2015-06-23 L. A. Balona , G. Catanzaro , O. P. Abedigamba , V. Ripepi , B. Smalley

A recent analysis of high precision photometry obtained using the Kepler spacecraft has revealed two surprising discoveries: (1) over 860 main sequence A-type stars -- approximately 40% of those identified in the Kepler field -- exhibit…

Solar and Stellar Astrophysics · Physics 2017-12-11 James Sikora , Gregg A. Wade , Jason Rowe