NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys

J. S. Jenkins, H. R A Jones, B. Biller, S. J. O'Toole, D. J. Pinfield, Laird M Close, C. G. Tinney, R. P. Butler, R. Wittenmyer, B. Carter, A. C. Day-Jones

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Context. Direct imaging of brown dwarfs as companions to solar-type stars can provide a wealth of well-constrained data to "benchmark" the physics of such objects, since quantities like metallicity and age can be determined from their well-studied primaries. Aims.We present results from an adaptive optics imaging program on stars drawn from the Anglo-Australian and Keck Planet Search projects, with the aim of directly imaging known cool companions. Methods. Simulations have modeled the expected contrast ratios and separations of known companions using estimates of orbital parameters available from current radial-velocity data and then a selection of the best case objects were followed-up with high contrast imaging to attempt to directly image these companions. Results. These simulations suggest that only a very small number of radial-velocity detected exoplanets with consistent velocity fits and age estimates could potentially be directly imaged using the VLT's Simultaneous Differential Imaging system and only under favorable conditions. We also present detectability confidence limits from the radial-velocity data sets and show how these can be used to gain a better understanding of these systems when combined with the imaging data. For HD32778 and HD91204 the detectabilities help little in constraining the companion and hence almost all our knowledge is drawn from the SDI images. Therefore, we can say that these stars do not host cool methane objects, out to on-sky separations of ∼2″, with contrasts less than 10.11 mag. However, for HD25874, HD120780 and HD145825, the contrasts and detectabilities can rule out a number of possible solutions, particularly at low angular separations, and for the best case, down to strong methane masses of 40 MJ at 1″ separation. The contrast curves constructed for these five stars show 5δ contrasts (δF1) of ∼9.2-11.5 mag at separations of ≥0.6″, which correspond to contrasts of ∼9.7-12.0 mag for companions of mid-T spectral type. Such limits allow us to reach down to 40 MJ around fairly old field dwarfs that typically constitute high precision radial-velocity programs. Finally, the analysis performed here can serve as a template for future projects that will employ extreme-AO systems to directly image planets already indirectly discovered by the radial-velocity method.

Original languageEnglish (US)
JournalAstronomy and Astrophysics
Volume515
Issue number2
DOIs
StatePublished - Jun 1 2010

Fingerprint

companion stars
planets
planet
radial velocity
stars
methane
old field
confidence limits
extrasolar planets
estimates
simulation
adaptive optics
physics
metallicity
sky
templates
orbitals
curves

Keywords

  • Binaries: general
  • Binaries: spectroscopic
  • Planetary systems
  • Stars: imaging
  • Technique: radial velocities
  • Techniques: high angular resolution

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Jenkins, J. S., Jones, H. R. A., Biller, B., O'Toole, S. J., Pinfield, D. J., Close, L. M., ... Day-Jones, A. C. (2010). NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys. Astronomy and Astrophysics, 515(2). https://doi.org/10.1051/0004-6361/200913737

NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys. / Jenkins, J. S.; Jones, H. R A; Biller, B.; O'Toole, S. J.; Pinfield, D. J.; Close, Laird M; Tinney, C. G.; Butler, R. P.; Wittenmyer, R.; Carter, B.; Day-Jones, A. C.

In: Astronomy and Astrophysics, Vol. 515, No. 2, 01.06.2010.

Research output: Contribution to journalArticle

Jenkins, JS, Jones, HRA, Biller, B, O'Toole, SJ, Pinfield, DJ, Close, LM, Tinney, CG, Butler, RP, Wittenmyer, R, Carter, B & Day-Jones, AC 2010, 'NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys', Astronomy and Astrophysics, vol. 515, no. 2. https://doi.org/10.1051/0004-6361/200913737
Jenkins, J. S. ; Jones, H. R A ; Biller, B. ; O'Toole, S. J. ; Pinfield, D. J. ; Close, Laird M ; Tinney, C. G. ; Butler, R. P. ; Wittenmyer, R. ; Carter, B. ; Day-Jones, A. C. / NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys. In: Astronomy and Astrophysics. 2010 ; Vol. 515, No. 2.
@article{62301dca47d14dd8ae4c1ac86825027d,
title = "NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys",
abstract = "Context. Direct imaging of brown dwarfs as companions to solar-type stars can provide a wealth of well-constrained data to {"}benchmark{"} the physics of such objects, since quantities like metallicity and age can be determined from their well-studied primaries. Aims.We present results from an adaptive optics imaging program on stars drawn from the Anglo-Australian and Keck Planet Search projects, with the aim of directly imaging known cool companions. Methods. Simulations have modeled the expected contrast ratios and separations of known companions using estimates of orbital parameters available from current radial-velocity data and then a selection of the best case objects were followed-up with high contrast imaging to attempt to directly image these companions. Results. These simulations suggest that only a very small number of radial-velocity detected exoplanets with consistent velocity fits and age estimates could potentially be directly imaged using the VLT's Simultaneous Differential Imaging system and only under favorable conditions. We also present detectability confidence limits from the radial-velocity data sets and show how these can be used to gain a better understanding of these systems when combined with the imaging data. For HD32778 and HD91204 the detectabilities help little in constraining the companion and hence almost all our knowledge is drawn from the SDI images. Therefore, we can say that these stars do not host cool methane objects, out to on-sky separations of ∼2″, with contrasts less than 10.11 mag. However, for HD25874, HD120780 and HD145825, the contrasts and detectabilities can rule out a number of possible solutions, particularly at low angular separations, and for the best case, down to strong methane masses of 40 MJ at 1″ separation. The contrast curves constructed for these five stars show 5δ contrasts (δF1) of ∼9.2-11.5 mag at separations of ≥0.6″, which correspond to contrasts of ∼9.7-12.0 mag for companions of mid-T spectral type. Such limits allow us to reach down to 40 MJ around fairly old field dwarfs that typically constitute high precision radial-velocity programs. Finally, the analysis performed here can serve as a template for future projects that will employ extreme-AO systems to directly image planets already indirectly discovered by the radial-velocity method.",
keywords = "Binaries: general, Binaries: spectroscopic, Planetary systems, Stars: imaging, Technique: radial velocities, Techniques: high angular resolution",
author = "Jenkins, {J. S.} and Jones, {H. R A} and B. Biller and O'Toole, {S. J.} and Pinfield, {D. J.} and Close, {Laird M} and Tinney, {C. G.} and Butler, {R. P.} and R. Wittenmyer and B. Carter and Day-Jones, {A. C.}",
year = "2010",
month = "6",
day = "1",
doi = "10.1051/0004-6361/200913737",
language = "English (US)",
volume = "515",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
publisher = "EDP Sciences",
number = "2",

}

TY - JOUR

T1 - NACO-SDI imaging of known companion host stars from the AAPS and Keck planet search surveys

AU - Jenkins, J. S.

AU - Jones, H. R A

AU - Biller, B.

AU - O'Toole, S. J.

AU - Pinfield, D. J.

AU - Close, Laird M

AU - Tinney, C. G.

AU - Butler, R. P.

AU - Wittenmyer, R.

AU - Carter, B.

AU - Day-Jones, A. C.

PY - 2010/6/1

Y1 - 2010/6/1

N2 - Context. Direct imaging of brown dwarfs as companions to solar-type stars can provide a wealth of well-constrained data to "benchmark" the physics of such objects, since quantities like metallicity and age can be determined from their well-studied primaries. Aims.We present results from an adaptive optics imaging program on stars drawn from the Anglo-Australian and Keck Planet Search projects, with the aim of directly imaging known cool companions. Methods. Simulations have modeled the expected contrast ratios and separations of known companions using estimates of orbital parameters available from current radial-velocity data and then a selection of the best case objects were followed-up with high contrast imaging to attempt to directly image these companions. Results. These simulations suggest that only a very small number of radial-velocity detected exoplanets with consistent velocity fits and age estimates could potentially be directly imaged using the VLT's Simultaneous Differential Imaging system and only under favorable conditions. We also present detectability confidence limits from the radial-velocity data sets and show how these can be used to gain a better understanding of these systems when combined with the imaging data. For HD32778 and HD91204 the detectabilities help little in constraining the companion and hence almost all our knowledge is drawn from the SDI images. Therefore, we can say that these stars do not host cool methane objects, out to on-sky separations of ∼2″, with contrasts less than 10.11 mag. However, for HD25874, HD120780 and HD145825, the contrasts and detectabilities can rule out a number of possible solutions, particularly at low angular separations, and for the best case, down to strong methane masses of 40 MJ at 1″ separation. The contrast curves constructed for these five stars show 5δ contrasts (δF1) of ∼9.2-11.5 mag at separations of ≥0.6″, which correspond to contrasts of ∼9.7-12.0 mag for companions of mid-T spectral type. Such limits allow us to reach down to 40 MJ around fairly old field dwarfs that typically constitute high precision radial-velocity programs. Finally, the analysis performed here can serve as a template for future projects that will employ extreme-AO systems to directly image planets already indirectly discovered by the radial-velocity method.

AB - Context. Direct imaging of brown dwarfs as companions to solar-type stars can provide a wealth of well-constrained data to "benchmark" the physics of such objects, since quantities like metallicity and age can be determined from their well-studied primaries. Aims.We present results from an adaptive optics imaging program on stars drawn from the Anglo-Australian and Keck Planet Search projects, with the aim of directly imaging known cool companions. Methods. Simulations have modeled the expected contrast ratios and separations of known companions using estimates of orbital parameters available from current radial-velocity data and then a selection of the best case objects were followed-up with high contrast imaging to attempt to directly image these companions. Results. These simulations suggest that only a very small number of radial-velocity detected exoplanets with consistent velocity fits and age estimates could potentially be directly imaged using the VLT's Simultaneous Differential Imaging system and only under favorable conditions. We also present detectability confidence limits from the radial-velocity data sets and show how these can be used to gain a better understanding of these systems when combined with the imaging data. For HD32778 and HD91204 the detectabilities help little in constraining the companion and hence almost all our knowledge is drawn from the SDI images. Therefore, we can say that these stars do not host cool methane objects, out to on-sky separations of ∼2″, with contrasts less than 10.11 mag. However, for HD25874, HD120780 and HD145825, the contrasts and detectabilities can rule out a number of possible solutions, particularly at low angular separations, and for the best case, down to strong methane masses of 40 MJ at 1″ separation. The contrast curves constructed for these five stars show 5δ contrasts (δF1) of ∼9.2-11.5 mag at separations of ≥0.6″, which correspond to contrasts of ∼9.7-12.0 mag for companions of mid-T spectral type. Such limits allow us to reach down to 40 MJ around fairly old field dwarfs that typically constitute high precision radial-velocity programs. Finally, the analysis performed here can serve as a template for future projects that will employ extreme-AO systems to directly image planets already indirectly discovered by the radial-velocity method.

KW - Binaries: general

KW - Binaries: spectroscopic

KW - Planetary systems

KW - Stars: imaging

KW - Technique: radial velocities

KW - Techniques: high angular resolution

UR - http://www.scopus.com/inward/record.url?scp=77953065148&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77953065148&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/200913737

DO - 10.1051/0004-6361/200913737

M3 - Article

AN - SCOPUS:77953065148

VL - 515

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

IS - 2

ER -