PHARO: A Near‐Infrared Camera for the Palomar Adaptive Optics System

Hayward, T. L.; Brandl, Bernhard R.; Pirger, Bruce; Blacken, C.; Gull, G. E.; Schoenwald, Justin; Houck, J. R.

doi:10.1086/317969

Cited by 203 publications

(192 citation statements)

References 20 publications

Supporting

Mentioning

184

Contrasting

Order By: Relevance

“…In typical observing situations, it has an inner working angle of approximately 1λ/D, or 90 mas in K-band (2.2 µm) behind the 5 m Hale telescope. It is installed between the P3K adaptive optics system (Dekany et al 2013) and the near-IR imager PHARO (Hayward et al 2001). Figure 4 shows a layout of the instrument.…”

Section: Stellar Double Coronagraphmentioning

confidence: 99%

Speckle suppression and companion detection using coherent differential imaging

Bottom

Wallace

Bartos

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Residual speckles due to aberrations arising from optical errors after the split between the wavefront sensor and the science camera path are the most significant barriers to imaging extrasolar planets. While speckles can be suppressed using the science camera in conjunction with the deformable mirror, this requires knowledge of the phase of the electric field in the focal plane. We describe a method which combines a coronagraph with a simple phase-shifting interferometer to measure and correct speckles in the full focal plane. We demonstrate its initial use on the Stellar Double Coronagraph at the Palomar Observatory. We also describe how the same hardware can be used to distinguish speckles from true companions by measuring the coherence of the optical field in the focal plane. We present results observing the brown dwarf HD 49197b with this technique, demonstrating the ability to detect the presence of a companion even when it is buried in the speckle noise, without the use of any standard "calibration" techniques. We believe this is the first detection of a substellar companion using the coherence properties of light.

show abstract

Section: Stellar Double Coronagraphmentioning

confidence: 99%

Speckle suppression and companion detection using coherent differential imaging

Bottom

Wallace

Bartos

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

show abstract

“…Epoch 14 observations were made at the Canada-France-Hawaii Telescope (Rigaut et al 1998). The observations comprising epochs 10, 12, and 15 were obtained with the Palomar AO system and the PHARO infrared camera (Hayward et al 2001). Astrometric points from epochs 6 through 15 are shown in The left and middle images were taken with a near-IR camera with a coronagraph at the AEOS telescope.…”

Section: Astrometric Observationsmentioning

confidence: 99%

“…(1) McCarthy (1983) and Kamper et al (1989) provide one-dimensional speckle measurements, (2) Boccaletti et al (2001), (3) Roberts & Neyman (2002), (4) Upper limit to orbit, (5) Sivaramakrishnan et al (2007), (6) Hayward et al (2001), (7) Hinkley et al (2008Hinkley et al ( , 2011, (8) Rigaut et al (1998). rotating. Recent interferometric imaging of several rapidly rotating A stars have revealed imaging of their surfaces (Monnier et al 2007;Zhao et al 2009).…”

Section: Introductionmentioning

confidence: 99%

ESTABLISHING α Oph AS A PROTOTYPE ROTATOR: IMPROVED ASTROMETRIC ORBIT

Hinkley

Monnier

Oppenheimer

et al. 2010

ApJ

View full text Add to dashboard Cite

The nearby star α Oph (Ras Alhague) is a rapidly rotating A5IV star spinning at ∼ 89% of its breakup velocity. This system has been imaged extensively by interferometric techniques, giving a precise geometric model of the star's oblateness and the resulting temperature variation on the stellar surface. Fortuitously, α Oph has a previously known stellar companion, and characterization of the orbit provides an independent, dynamically based check of both the host star and the companion mass. Such measurements are crucial to constrain models of such rapidly rotating stars. In this study, we combine eight years of adaptive optics imaging data from the Palomar, AEOS, and CFHT telescopes to derive an improved, astrometric characterization of the companion orbit. We also use photometry from these observations to derive a model-based estimate of the companion mass. A fit was performed on the photocenter motion of this system to extract a component mass ratio. We find masses of 2.40 +0.23 −0.37 M and 0.85 +0.06 −0.04 M for α Oph A and α Oph B, respectively. Previous orbital studies of this system found a mass too high for this system, inconsistent with stellar evolutionary calculations. Our measurements of the host star mass are more consistent with these evolutionary calculations, but with slightly higher uncertainties. In addition to the dynamically derived masses, we use IJHK photometry to derive a model-based mass for α Oph B, of 0.77 ± 0.05 M marginally consistent with the dynamical masses derived from our orbit. Our model fits predict a periastron passage on 2012 April 19, with the two components having a 50 mas separation from 2012 March to May. A modest amount of interferometric and radial velocity data during this period could provide a mass determination of this star at the few percent level.

show abstract

“…Additionally, Kepler-9 was observed on 2010 July 2 at the Palomar Hale 200 inch telescope with the near-infrared adaptive optics (AO) PHARO instrument (Hayward et al 2001), a 1024 × 1024 Rockwell HAWAII HgCdTe array detector. Observations were made in the J (1.25 μm) and K s (2.145 μm) bands.…”

Section: Additional Observations For False Positive Rejectionmentioning

confidence: 99%

MODELINGKEPLERTRANSIT LIGHT CURVES AS FALSE POSITIVES: REJECTION OF BLEND SCENARIOS FOR KEPLER-9, AND VALIDATION OF KEPLER-9 d, A SUPER-EARTH-SIZE PLANET IN A MULTIPLE SYSTEM

Torres

Fressin

Batalha

et al. 2010

ApJ

230

176

View full text Add to dashboard Cite

Light curves from the Kepler Mission contain valuable information on the nature of the phenomena producing the transit-like signals. To assist in exploring the possibility that they are due to an astrophysical false positive, we describe a procedure (BLENDER) to model the photometry in terms of a "blend" rather than a planet orbiting a star. A blend may consist of a background or foreground eclipsing binary (or star-planet pair) whose eclipses are attenuated by the light of the candidate and possibly other stars within the photometric aperture. We apply BLENDER to the case of Kepler-9 (KIC 3323887), a target harboring two previously confirmed Saturn-size planets (Kepler-9 b and Kepler-9 c) showing transit timing variations, and an additional shallower signal with a 1.59 day period suggesting the presence of a super-Earth-size planet. Using BLENDER together with constraints from other follow-up observations we are able to rule out all blends for the two deeper signals and provide independent validation of their planetary nature. For the shallower signal, we rule out a large fraction of the false positives that might mimic the transits. The false alarm rate for remaining blends depends in part (and inversely) on the unknown frequency of small-size planets. Based on several realistic estimates of this frequency, we conclude with very high confidence that this small signal is due to a super-Earth-size planet (Kepler-9 d) in a multiple system, rather than a false positive. The radius is determined to be 1.64 +0.19 −0.14 R ⊕ , and current spectroscopic observations are as yet insufficient to establish its mass.

show abstract

PHARO: A Near‐Infrared Camera for the Palomar Adaptive Optics System

Cited by 203 publications

References 20 publications

Speckle suppression and companion detection using coherent differential imaging

Speckle suppression and companion detection using coherent differential imaging

ESTABLISHING α Oph AS A PROTOTYPE ROTATOR: IMPROVED ASTROMETRIC ORBIT

MODELINGKEPLERTRANSIT LIGHT CURVES AS FALSE POSITIVES: REJECTION OF BLEND SCENARIOS FOR KEPLER-9, AND VALIDATION OF KEPLER-9 d, A SUPER-EARTH-SIZE PLANET IN A MULTIPLE SYSTEM

Contact Info

Product

Resources

About