inferences on the solar-stellar connection and stellar ... · solar-stellar connection and stellar...
TRANSCRIPT
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)
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
Chaplin et al., 2013, ApJ, 766, 101
Rotation of main-sequence starsDipole modes in two Kepler planet hosting stars
Kepler-50 Kepler-65
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
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
Kepler: solar-type stars with
3+ years of asteroseismic data
Kepler Objects of Interest
KASC field stars