Inferences on the

solar-stellar

connection and stellar

activity from space-

based photometry

Bill Chaplin, School of Physics & Astronomy University of Birmingham, UK

Solar Dynamo Frontiers Workshop, Boulder, 2015 June 12

Stellar Astrophysics

Centre (SAC)

The Kepler Mission

Signatures of stellar activityKepler lightcurves of solar-type stars

Basri et al., 2011, ApJL, 713, 155

CoRoT observations of the

solar-type star HD181420

Barban et al., 2009, A&A, 506, 51

Mosser et al., 2009, A&A, 506, 245

surface rotation asteroseismology

Kepler’s “best in class”

Metcalfe et al., 2012, ApJ, 748, L10

16 Cyg A 16 Cyg BM = 1.11M

M = 1.07M

Solar-type binary 16 Cyg (age 6.8 Gyr)

Metcalfe et al., 2012, ApJ, 748, L10

Kepler’s “best in class”

16 Cyg A 16 Cyg BM = 1.11M

M = 1.07M

Solar-type binary 16 Cyg (age 6.8 Gyr)

solar-like oscillations

granulation

activity

shot noise

Surface temperature (degrees Kelvin)

Lum

inosity (

×S

un)

Approx. 700 solar-type stars

Approx.16,000 red giants

Over 100 planet-hosting stars

Asteroseismology

of solar-like

oscillators

Kepler

Surface temperature (degrees Kelvin)

Lum

inosity (

×S

un)

Surface rotation periods for

300+ of the asteroseismic

sample of solar-type stars

Asteroseismology

of solar-like

oscillators

Kepler

García et al., 2014, A&A, 572, A34

Nielsen et al., 2013, A&A, 568, L12

Rotation of main-sequence starsl=2,0 and 1 modes in Kepler target KIC 6106415

2

0 1

Inference on stellar inclinationExample: dipole mode of oscillation

A. Miglio

Chaplin et al., 2013, ApJ, 766, 101

Rotation of main-sequence starsDipole modes in two Kepler planet hosting stars

Kepler-50 Kepler-65

Davies et al., in preparation

Analysis of ~40 Kepler targets

Rotation of main-sequence stars

Age-rotation comparisons

Garcia et al. 2014 A&A, 572, 34

Davies et al. 2014, MNRAS 446, 2959

do Nascimento Jr. et al. 2014, ApJ, 790, L23

Internal rotation of a subgiantCore rotates five-times faster than surface

Deheuvels et al., 2012, ApJ, 756, 19

Internal rotation from Kepler

Deheuvels et al., 2014, A&A, 564, 27

envelopes

cores

Ω/2

π(n

Hz)

log g (dex)Teff (K)

∆ν

(µH

z)

sub-giants and low-luminosity red giants

Convective

envelope depth

Mazumdar et al., 2014, ApJ, 782, 18

From “acoustic glitches”

− Kepler example: Sun-like dwarf

− Signal present in particular combinations of frequencies

Search for signatures of

stellar cycles in Kepler data

Stellar cycles with Kepler?From variability of lightcurve: two F-type stars

Mathur et al., 2014, A&A, 562, 124

Time (days)

Time (days)

δF

/F(p

pm

)

The Sun amongst stars

Gilliland, Chaplin et al., 2015, ApJ, submitted

Kepler stars

Sun

Selection of solar-type stars (Kepler) and

the Sun (SOHO/VIRGO)

“Sounding” stellar activity cycles: SunThree solar cycles with BiSON Sun-as-a-star data

scaled 10.7-cm radio flux

Broomhall et al., 2012, MNRAS, 420, 1405

Quasi-biennial variation

After removal of

11-yr cycle

signature

CoRoT reveals a short activity

cycle in HD49933

García et al., 2010, Science, 329, 1032

Kepler: solar-type stars with

3+ years of asteroseismic data

Kepler Objects of Interest

KASC field stars

End