J/A+A/695/A21 Flaring activities of fast rotating stars (Yang+, 2025)
Flaring activities of fast rotating stars have solar-like latitudinal
distribution.
Yang H., Cheng X., Liu J., Liu S., Zhao Z., Zhou G., Hou Y., Gao C., Niu Z.
<Astron. Astrophys. 695, A21 (2025)>
=2025A&A...695A..21Y 2025A&A...695A..21Y (SIMBAD/NED BibCode)
ADC_Keywords: Stars, activity ; Stars, flare ; Rotational velocities ;
Stars, diameters
Keywords: Sun: activity - Sun: flare - Sun: activity - Sun: flare -
stars: late-type
Abstract:
The dynamo theory has always been one of the biggest mysteries in
stellar physics. One key reason for its uncertainty is poor knowledge
of the dynamo process on stars except the Sun. The most important
observation feature of solar dynamo is that active regions only appear
at low latitudes, which provides a crucial constraint to the dynamo
theory, while Doppler imaging, the current technique to spatially
resolve stellar hemisphere, is difficult to distinguish the equatorial
region . Hence, the latitudinal distribution of active regions (LDAR)
of stars is ambiguous and controversial, mainly due to the limit of
the current technique for spatially resolving the stellar surface.
Fast rotating stars, which are young and active, are thought to
operate with a different dynamo process than the Sun. We study their
LDAR and compare them with the Sun to reveal the underlying dynamo
process.
Flares are drastic and observational activity events, which occur in
active regions. Here, we propose a new method to study how the
apparent flaring activity varies with respect to the inclination to
determine the LDAR of fast rotating stars.
We find that the LDAR of fast rotating stars is consistent with that
of the Sun, contrary to expectations. Our results provide a crucial
constraint to stellar dynamo, indicating that the solar-like dynamo
also applies to fast rotating stars, even spanning different stages of
their evolution.
Description:
We calculate the flaring activity and inclination of 201 stars through
the 4-year lightcurves of the Kepler Mission and the spectra of
APOGEE. This table presents the related parameters.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 76 201 Flaring activity and inclination of 201 stars
through the 4-year lightcurves of the Kepler
Mission and the spectra of APOGEE
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC The Kepler input catalog ID
11- 17 F7.2 K Teff Effective temperature
20- 23 F4.2 [cm/s2] logg Surface gravity
25- 29 F5.3 --- Ro Rossby number, the ratio of rotation period
to the global convective turnover time
32- 36 F5.3 Rsun Rad Stellar radius derived from the SPOTS model
39- 43 F5.3 --- b_sini The lower limit of sini
46- 50 F5.3 --- sini The sine value of the inclination angle
53- 57 F5.3 --- B_sini The upper limit of sini
59- 64 F6.3 --- FA Flaring activity
67- 72 F6.3 m/s vsini Projected rotational velocity
74- 76 A3 --- BF [Yes/No ] Binary flag
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Acknowledgements:
Huiqin Yang, yhq(at)nao.cas.cn
(End) Patricia Vannier [CDS] 30-Jan-2025