2019A&A...626A..38L


Query : 2019A&A...626A..38L

2019A&A...626A..38L - Astronomy and Astrophysics, volume 626A, 38-38 (2019/6-1)

Stellar activity and rotation of the planet host Kepler-17 from long-term space-borne photometry.

LANZA A.F., NETTO Y., BONOMO A.S., PARVIAINEN H., VALIO A. and AIGRAIN S.

Abstract (from CDS):


Context. The study of young Sun-like stars is fundamental to understanding the magnetic activity and rotational evolution of the Sun. Space-borne photometry by the Kepler telescope provides unprecedented datasets to investigate these phenomena in Sun-like stars.
Aims. We present a new analysis of the entire Kepler photometric time series of the moderately young Sun-like star Kepler-17 accompanied by a transiting hot Jupiter.
Methods. We applied a maximum-entropy spot model to the long-cadence out-of-transit photometry of the target to derive maps of the starspot filling factor versus the longitude and the time. These maps are compared to the spots occulted during transits to validate our reconstruction and derive information on the latitudes of the starspots.
Results. We find two main active longitudes on the photosphere of Kepler-17, one of which has a lifetime of at least ∼1400 days although with a varying level of activity. The latitudinal differential rotation is of solar type, that is, with the equator rotating faster than the poles. We estimate a minimum relative amplitude ΔΩ/Ω between ∼0.08±0.05 and 0.14±0.05, our determination being affected by the finite lifetime of individual starspots and depending on the adopted spot model parameters. We find marginal evidence of a short-term intermittent activity cycle of ∼48 days and an indication of a longer cycle of 400-600 days characterized by an equatorward migration of the mean latitude of the spots as in the Sun. The rotation of Kepler-17 is likely to be significantly affected by the tides raised by its massive close-by planet. Conclusion. We confirm the reliability of maximum-entropy spot models to map starspots in young active stars and characterize the activity and differential rotation of this young Sun-like planetary host.

Abstract Copyright: © ESO 2019

Journal keyword(s): stars: activity - stars: rotation - stars: late-type - starspots - planetary systems - techniques: photometric

VizieR on-line data: <Available at CDS (J/A+A/626/A38): k17bola.dat k17arc2.dat>

Simbad objects: 11

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Number of rows : 11
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 * iot Hor PM* 02 42 33.4666679022 -50 48 01.055138166   5.97 5.40     F8V 365 1
2 HD 22468 RS* 03 36 47.2911034958 +00 35 15.938962144 7.09 6.79 5.90 5.4   K2:Vnk 1146 0
3 * 58 Eri BY* 04 47 36.2917029384 -16 56 04.040472552   6.14 5.50     G2.5IV-V 400 0
4 HD 76151 PM* 08 54 17.9470964696 -05 26 04.054298491 6.89 6.67 6.00     G2V 493 0
5 CoRoT-6 * 18 44 17.4078666144 +06 39 47.513042100   14.68 13.80 14.18   F5V 42 1
6 CoRoT-2 * 19 27 06.4944378024 +01 23 01.359897468   13.422 12.568 12.204 11.49 G7V+K9V 228 2
7 G 208-42 Er* 19 51 09.3205973189 +46 29 00.213809780   14.47   12.544   M4.0V 150 0
8 Kepler-17b Pl 19 53 34.8642919207 +47 48 54.049941399           ~ 86 1
9 Kepler-17 Ro* 19 53 34.8643397568 +47 48 54.049530564   14.6   13.6   G5V 132 1
10 * 15 Sge PM* 20 04 06.2207683221 +17 04 12.676556401   6.390 5.788 5.4   G0V 360 0
11 HD 224085 RS* 23 55 04.0520383542 +28 38 01.245426862 8.88 8.20   6.9   K2+IVeFe-1 704 0

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2022.05.28-10:40:29

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