Flare Statistics for Young Stars from a Convolutional Neural Network Analysis of TESS Data

All-sky photometric time-series missions have allowed for the monitoring of thousands of young (t(age) < 800 Myr) stars in order to understand the evolution of stellar activity. Here, we developed a convolutional neural network (CNN), stella, specifically trained to find flares in Transiting Exop...

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Bibliographic Details
Published in:The Astronomical journal Vol. 160; no. 5; pp. 219 - 234
Main Authors: Feinstein, Adina D., Montet, Benjamin T., Ansdell, Megan, Nord, Brian, Bean, Jacob L., Günther, Maximilian N., Gully-Santiago, Michael A., Schlieder, Joshua E.
Format: Journal Article
Language:English
Published: Goddard Space Flight Center The American Astronomical Society 01.11.2020
IOP Publishing / American Astronomical Society
IOP Publishing
IOP Publishing - AAAS
Subjects:
Amplitudes
Artificial neural networks
Astronomy
ASTRONOMY AND ASTROPHYSICS
Astrophysics
Convolutional neural networks
Extrasolar planets
INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
Light curve
Network analysis
Neural networks
Planet detection
PMS stars
Pre-main sequence stars
Source code
Stars
Stellar activity
Stellar age
Stellar evolution
Stellar flares
Stellar rotation
Time series analysis
Toolkits
Transit
ISSN:0004-6256, 1538-3881, 1538-3881
Online Access:Get full text
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Summary:All-sky photometric time-series missions have allowed for the monitoring of thousands of young (t(age) < 800 Myr) stars in order to understand the evolution of stellar activity. Here, we developed a convolutional neural network (CNN), stella, specifically trained to find flares in Transiting Exoplanet Survey Satellite (TESS) short-cadence data. We applied the network to 3200 young stars in order to evaluate flare rates as a function of age and spectral type. The CNN takes a few seconds to identify flares on a single light curve. We also measured rotation periods for 1500 of our targets and find that flares of all amplitudes are present across all spot phases, suggesting high spot coverage across the entire surface. Additionally, flare rates and amplitudes decrease for stars t(age) > 50 Myr across all temperatures T(eff) ≥ 4000 K, while stars from 2300 ≤ T(eff) < 4000 K show no evolution across 800 Myr. Stars of T(eff) ≤ 4000 K also show higher flare rates and amplitudes across all ages. We investigate the effects of high flare rates on photoevaporative atmospheric mass loss for young planets. In the presence of flares, planets lose 4%–7% more atmosphere over the first 1 Gyr. stella is an open-source Python toolkit hosted on GitHub and PyPI.
Bibliography:AAS24551
Stars and Stellar Physics
GSFC
Goddard Space Flight Center
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
FERMILAB-PUB-20-593-SCD
USDOE Office of Science (SC), High Energy Physics (HEP)
National Science Foundation (NSF)
AC02-07CH11359; DGE-1746045
ISSN:0004-6256
1538-3881
1538-3881
DOI:10.3847/1538-3881/abac0a