Imaging Spotted RS CVn Binarieschara.gsu.edu/files/2015Meeting/Roettenbacher_2015.pdf• Compare...

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


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


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


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


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


-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)


ο Dra Radial Velocity Curve


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


ο Dra Mass and Evolution



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


o Dra



Main sequence companion


•  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


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



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


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



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

)



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



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


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



Main-sequence Companion


•  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


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


Preliminary σ Gem Imaging Results


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


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)

Imaging Spotted RS CVn Binarieschara.gsu.edu/files/2015Meeting/Roettenbacher_2015.pdf• Compare...

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