CHARA 2015 Towards Adaptive Optics at CHARA
Imaging Spotted RS CVn Binaries
Rachael Roettenbacher University of Michigan
John Monnier, Fabien Baron, Xiao Che, Ettore Pedretti, Heidi Korhonen, Bob Harmon, Greg Henry, Frank Fekel, Mike Williamson, Dave Latham, and the CHARA Collaboration
CHARA 2015 Towards Adaptive Optics at CHARA
Imaging Spotted Stars with CHARA
• Compare aperture synthesis images with contemporaneous Doppler imaging and light-curve inversion results
• Interferometry from MIRC 6T • High-resolution spectroscopy from VLT, NOT,
STELLA robotic telescope • Photometry from APT and SMARTS • RS CVn targets: ζ And and σ Gem
CHARA 2015 Towards Adaptive Optics at CHARA
RS CVn Binaries • Giant or subgiant primary
component • Subgiant or dwarf
secondary component • Exhibit photometric and
Ca H and K variability • Interesting starspot features
• Polar spots • Active longitudes
• Close binaries • Short rotation and orbital
periods • Often tidally-locked • No mass transfer Hall 1976, Berdyugina 2005, Strassmeier 2009
CHARA 2015 Towards Adaptive Optics at CHARA
o Dra
370x fainter than primary
Red Giant Primary Star R1 = 25.2 +\- 0.2 Rsun
Main sequence companion
Roettenbacher et al. in prep.
• G9III primary • Teff ~ 4430 K • Prot ~ 70 days • Porb ~138 days • Active primary
• Spot evolution • Ca H & K variation
• No direct detections of the companion star
CHARA 2015 Towards Adaptive Optics at CHARA
ο Dra Orbit
Roettenbacher et al. in prep. 6 4 2 0 -2 -4 -6
milliarcsecond
-6
-4
-2
0
2
4
6
milli
arcs
econ
d
2012 May 092012 May 12
2012 Jun 172012 Jun 18
2014 May 262014 May 27
o Dra A
o Dra B
CHARA 2015 Towards Adaptive Optics at CHARA
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2Phase
-60
-40
-20
0
Velo
city
(km
/s)
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2Phase
-20
0
20
40
60
80
100
Radia
l Velo
city
(km
/s)
Roettenbacher et al. in prep.
ο Dra Radial Velocity Curve
CHARA 2015 Towards Adaptive Optics at CHARA
8000 7000 6000 5000 4000Teff (K)
1
10
100
Bolo
met
ric L
umin
osity
(LSu
n)
ZAMS3 Gyr IsochronePrimary Evolutionary
track(1.36 MSun) with 1-m Mass ErrorsSecondary Evolutionary Track
(0.99 MSun) with 1-m Mass ErrorsPrimary Stellar Parameters with 1-m ErrorsSecondary Stellar Parameters with 1-m Errors
Roettenbacher et al. in prep.
ο Dra Mass and Evolution
CHARA 2015 Towards Adaptive Optics at CHARA
Roettenbacher et al. in prep.
ο Dra Ellipsoidal Variations
0.060.04
0.02
0.00
-0.02
-0.04
6 B
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2Phase
0.060.04
0.02
0.00
-0.02
-0.04
6 V
` = 0.08` = 0.08` = 0.08` = 0.08` = 0.08` = 0.25` = 0.25` = 0.25` = 0.25` = 0.25
CHARA 2015 Towards Adaptive Optics at CHARA
o Dra
370x fainter than primary
Red Giant Primary Star R1 = 25.2 +\- 0.2 Rsun
Main sequence companion
Roettenbacher et al. in prep.
• t ~ 3 +/- 0.5 Gyr • M1 = 1.36 +/- 0.04 Msun • M2 = 0.99 +/- 0.02 Msun • T1 ~ 4430 +/- 130 K • T2 ~ 6000 +400/-300 K • R1 = 25.2 +/- 0.2 Rsun • R2 = 1.0 +/- 0.1 Rsun • Active primary?
• Ellipsoidal variations • Eclipsing
CHARA 2015 Towards Adaptive Optics at CHARA
σ Gem
4 2014 – Submission Deadline: 13 Dec 2013, midnight EST (Friday night)– Submit to [email protected]
J. Science Justification/Figures/Tables (Insert as needed) –
Figure 1 (left) shows a detection of the binary companion of σ Gem (flux ratio 250:1; 2012 Nov 7). Figure 1 (right) is our orbit fit of σ Gem (red; with parameters given in Dümmler et al. 1997) with σ Gem using our radius (dotted line) and our dates of detection and their locations on the orbit (diamonds).
Figure 2 (left) shows the detection of the binary companion of ο Dra (flux ratio 350:1; 2012 Jun 18). Figure 2 (right) is in the same sense as Figure 1 (right) for ο Dra (with orbital parameters from D. Latham). The detections of ο Dra are less robust, so request more observations to improve the quality of our binary fit and determine the masses and spectral types of the components. References Dümmler, R., Ilyin, I. V., & Tuominen, I. 1997, A&AS, 123, 209 Habets, G. M. H. J. & Zwaan, C. 1989, A&A, 211, 56 Hall, D. S. & Persinger, W. T. 1986, LNP, 254, 88 Henry, G. W., Eaton, J. A., Hamer, J., & Hall, D. S. 1995, ApJS, 97, 513 Lucy, L. B. & Sweeney, M. A. 1971, AJ, 76, 544 Young, R. K. 1920, PDAO, 1, 263 Zahn, J.-P. 1977, A&A, 57, 383
270x fainter than primary
Red Giant Primary Star R1 = 10.1 +\- 0.2 Rsun
Main-sequence Companion
Roettenbacher et al. submitted
• K1III primary • Teff ~ 4530 K • Prot ~ Porb ~19.6 days • Active primary
• Active longitudes • Spot evolution • Differential
rotation • No direct detections of
the companion star
CHARA 2015 Towards Adaptive Optics at CHARA
σ Gem Orbit
Roettenbacher et al. submitted 4 2 0 -2 -4
milliarcsecond
-4
-2
0
2
4m
illiar
csec
ond
2011 Dec 08
2012 Nov 072012 Nov 08
2012 Nov 24
2012 Nov 25
m Gem A m Gem B
CHARA 2015 Towards Adaptive Optics at CHARA
Roettenbacher et al. submitted
σ Gem Radial Velocity Curve
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2Phase
-20
0
20
40
60
80
100
Rad
ial V
eloc
ity (k
m/s
)
CHARA 2015 Towards Adaptive Optics at CHARA
Roettenbacher et al. submitted
σ Gem Mass and Evolution
7000 6000 5000 4000 3000Teff (K)
0.01
0.10
1.00
10.00
100.00
Bolo
met
ric L
umin
osity
(LSu
n)
ZAMS5 Gyr IsochronePrimary Evolutionary Track (1.28 MSun) with 1-m Mass ErrorsSecondary Evolutionary Track (0.73 MSun) with 1-m Mass ErrorsPrimary Stellar Parameters with 1-m ErrorsSecondary Stellar Parameters with 1-m Errors
CHARA 2015 Towards Adaptive Optics at CHARA
Roettenbacher et al. submitted
σ Gem Ellipsoidal Variations
0.060.04
0.02
0.00
-0.02
-0.04
6 B
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2Phase
0.060.04
0.02
0.00
-0.02
-0.04
6 V
` = 0.02` = 0.02` = 0.02` = 0.02` = 0.02` = 0.08` = 0.08` = 0.08` = 0.08` = 0.08` = 0.25` = 0.25` = 0.25` = 0.25` = 0.25
CHARA 2015 Towards Adaptive Optics at CHARA
σ Gem
4 2014 – Submission Deadline: 13 Dec 2013, midnight EST (Friday night)– Submit to [email protected]
J. Science Justification/Figures/Tables (Insert as needed) –
Figure 1 (left) shows a detection of the binary companion of σ Gem (flux ratio 250:1; 2012 Nov 7). Figure 1 (right) is our orbit fit of σ Gem (red; with parameters given in Dümmler et al. 1997) with σ Gem using our radius (dotted line) and our dates of detection and their locations on the orbit (diamonds).
Figure 2 (left) shows the detection of the binary companion of ο Dra (flux ratio 350:1; 2012 Jun 18). Figure 2 (right) is in the same sense as Figure 1 (right) for ο Dra (with orbital parameters from D. Latham). The detections of ο Dra are less robust, so request more observations to improve the quality of our binary fit and determine the masses and spectral types of the components. References Dümmler, R., Ilyin, I. V., & Tuominen, I. 1997, A&AS, 123, 209 Habets, G. M. H. J. & Zwaan, C. 1989, A&A, 211, 56 Hall, D. S. & Persinger, W. T. 1986, LNP, 254, 88 Henry, G. W., Eaton, J. A., Hamer, J., & Hall, D. S. 1995, ApJS, 97, 513 Lucy, L. B. & Sweeney, M. A. 1971, AJ, 76, 544 Young, R. K. 1920, PDAO, 1, 263 Zahn, J.-P. 1977, A&A, 57, 383
270x fainter than primary
Red Giant Primary Star R1 = 10.1 +\- 0.2 Rsun
Main-sequence Companion
Roettenbacher et al. submitted
• t ~ 5 +/- 1 Gyr • M1 = 1.28 +/- 0.07 Msun • M2 = 0.73 +/- 0.02 Msun • T1 ~ 4530 +/- 60 K • T2 ~ 4300 K • R1 = 10.1 +/- 0.2 Rsun • R2 ~ 0.7 Rsun • Active primary
• Large starspots • Ellipsoidal variations
CHARA 2015 Towards Adaptive Optics at CHARA
RS CVn Imaging
• Interferometry • MIRC (2011, 2012)
• Spectroscopy • VLT (2011, 2012) • STELLA (2011) • NOT (2012)
• Photometry • AST (2011, 2012) • CTIO (2012)
σ Gem • Interferometry
• MIRC (2011, 2013) • Spectroscopy
• STELLA (2011) • VLT (2013) • Belgian Mercator (2013)
• Photometry • AST (2011, 2013) • CTIO (2013)
ζ And
CHARA 2015 Towards Adaptive Optics at CHARA
Preliminary σ Gem Imaging Results
CHARA 2015 Towards Adaptive Optics at CHARA
Preliminary σ Gem SIMOI Results
2011 Nov 9 2011 Dec 7 2011 Dec 8 2011 Dec 9
Phase = 0.25
Phase = 0.25
Phase = 0.30
CHARA 2015 Towards Adaptive Optics at CHARA
Summary and Future Work
• CHARA/MIRC detected faint main sequence companions
• RS CVns present ellipsoidal variations • Obtained visual orbit of σ Gem and ο Dra • Image spots with interferometry, spectroscopy,
and photometry (σ Gem and ζ And)