Krzysztof Helminiak

HIGH-PRECISION ORBITAL AND PHYSICAL PARAMETERS OF DOUBLE-LINED SPECTROSCOPIC BINARY STARS—HD78418, HD123999, HD160922, HD200077, AND HD210027

We present high-precision radial velocities (RVs) of double-lined spectroscopic binary stars HD78418, HD123999, HD160922, HD200077, and HD210027. They were obtained based on the high-resolution echelle spectra collected with the Keck I/HIRES, Shane/CAT/Hamspec, and TNG/Sarge telescopes/spectrographs over the years 2003-2008 as part of the TATOOINE search for circumbinary planets. The RVs were computed using our novel iodine cell technique for double-line binary stars, which relies on tomographically disentangled spectra of the components of the binaries. The precision of the RVs is of the order of 1-10 m s^(–1), and to properly model such measurements one needs to account for the light-time effect within the binarys orbit, relativistic effects, and RV variations due to tidal distortions of the components of the binaries. With such proper modeling, our RVs combined with the archival visibility measurements from the Palomar Testbed Interferometer (PTI) allow us to derive very precise spectroscopic/astrometric orbital and physical parameters of the binaries. In particular, we derive the masses, the absolute K- and H-band magnitudes, and the parallaxes. The masses together with the absolute magnitudes in the K and H bands enable us to estimate the ages of the binaries. These RVs allow us to obtain some of the most accurate mass determinations of binary stars. The fractional accuracy in msin i only, and hence based on the RVs alone, ranges from 0.02% to 0.42%. When combined with the PTI astrometry, the fractional accuracy in the masses in the three best cases ranges from 0.06% to 0.5%. Among them, the masses of HD210027 components rival in precision the mass determination of the components of the relativistic double pulsar system PSR J0737 – 3039. In the near future, for double-lined eclipsing binary stars we expect to derive masses with a fractional accuracy of the order of up to ~0.001% with our technique. This level of precision is an order of magnitude higher than of the most accurate mass determination for a body outside the solar system—the double neutron star system PSR B1913+16.

THE RADIAL VELOCITY TATOOINE SEARCH FOR CIRCUMBINARY PLANETS: PLANET DETECTION LIMITS FOR A SAMPLE OF DOUBLE-LINED BINARY STARS-INITIAL RESULTS FROM KECK I/HIRES, SHANE/CAT/HAMSPEC, AND TNG/SARG OBSERVATIONS

We present preliminary results of the first and on-going radial velocity survey for circumbinary planets. With a novel radial velocity technique employing an iodine absorption cell, we achieve an unprecedented radial velocity (RV) precision of up to 2 m s^(–1) for double-lined binary stars. The high-resolution spectra collected with the Keck I/Hires, TNG/Sarg, and Shane/CAT/Hamspec telescopes/spectrographs over the years 2003-2008 allow us to derive RVs and compute planet detection limits for 10 double-lined binary stars. For this initial sample of targets, we can rule out planets on dynamically stable orbits with masses as small as ~0.3 to 3 M_(Jup) for the orbital periods of up to ~5.3 years. Even though the presented sample of stars is too small to make any strong conclusions, it is clear that the search for circumbinary planets is now technique-wise possible and eventually will provide new constraints for the planet formation theories

Orbital and physical parameters of eclipsing binaries from the All-Sky Automated Survey catalogue - II. Two spotted M < 1 M⊙ systems at different evolutionary stages

Aims. We present the results of our detailed spectroscopic and photometric analysis of two previously unknown <1 Mdetached eclipsing binaries: ASAS J045304-0700.4 and ASAS J082552-1622.8. Methods. With the HIgh Resolution Echelle Spectrometer (HIRES) on the Keck-I telescope, we obtained spectra of both objects covering large fractions of orbits of the systems. We also obtained V and I band photometry with the 1.0-m Elizabeth telescope of the South African Astronomical Observatory (SAAO). The orbital and physical parameters of the systems were derived with the PHOEBE and JKTEBOP codes. We investigated the evolutionary status of both binaries with several sets of widely-used isochrones. Results. Our modelling indicates that (1) ASAS J045304-0700.4 is an old, metal-poor, active system with component masses of M1 = 0.8338 ± 0.0036 M� , M2 = 0.8280 ± 0.0040 Mand radii of R1 = 0.848 ± 0.005 Rand R2 = 0.833 ± 0.005 R� , which places it at the end of the Main Sequence evolution - a stage rarely observed for this type of stars. (2) ASAS J082552-1622.8 is a metal-rich, active binary with component masses of M1 = 0.7029 ± 0.0045 M� , M2 = 0.6872 ± 0.0049 Mand radii of R1 = 0.694 +0.007 −0.011 Rand R2 = 0.699 +0.011 −0.014 R� . Both systems show significant out-of-eclipse variations, probably owing to large, cold spots. We also investigated the influence of a third light in the second system.

Impact of the atmospheric refraction on the precise astrometry with adaptive optics in infrared

Abstract We study the impact of the atmospheric differential chromatic refraction on the measurements and precision of relative astrometry. Specifically, we address the problem of measuring the separations of close pairs of binary stars with adaptive optics in the J and K bands. We investigate the influence of weather conditions, zenithal distance, star’s spectral type and observing wavelength on the astrometric precision and determine the accuracy of these parameters that is necessary to detect exoplanets with existing and planned large ground based telescopes with adaptive optics facilities. The analytical formulae for simple monochromatic refraction and a full approach, as well as moderately simplified procedure, are used to compute refraction corrections under a variety of observing conditions. It is shown that the atmospheric refraction must be taken into account in astrometric studies but the full procedure is not necessary in many cases. Requirements for achieving a certain astrometric precision are specified.

Absolute properties of the main‐sequence eclipsing binary FM Leo

First spectroscopic and new photometric observations of the eclipsing binary FM Leo are presented. The main aims were to determine the orbital and stellar parameters of the two components and their evolutionary stage. First spectroscopic observations of the system were obtained with the David Dunlap Observatory and Pozna´ n Spectroscopic Telescope spectrographs. The results of the orbital solution from radial velocity curves are combined with those derived from the light-curve analysis (V-band photometry from the All Sky Automated Survey and supplementary observations of eclipses with the 1 and 0.35 m telescopes) to derive orbital and stellar parameters. JKTEBOP, Wilson–Devinney binary modelling codes and a twodimensional cross-correlation method were applied for the analysis. We find the masses to be M

Precision astrometry of a sample of speckle binaries and multiples with the adaptive optics facilities at the Hale and Keck II telescopes

Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in nthe near-infrared a sample of 12 binary and multiple stars and one open cluster. We used nthe near diffraction limited images of these systems to measure the relative separations and nposition angles between their components. In this paper, we investigate and correct for the ninfluence of the differential chromatic refraction and chip distortions on our relative astrometric nmeasurements. Over one night, we achieve an astrometric precision typically well below 1mas nand occasionally as small as 40 μas. Such a precision is in principle sufficient to astrometrically ndetect planetary mass objects around the components of nearby binary and multiple stars. Since nwe have not had sufficiently large data sets for the observed sample of stars to detect planets, nwe provide the limits to planetary mass objects based on the obtained astrometric precision.

Non-Keplerian effects in precision radial velocity measurements of double-line spectroscopic binary stars: numerical simulations

Current precision in radial velocity (RV) measurements of binary stars reaches

New high-precision orbital and physical parameters of the double-lined low-mass spectroscopic binary BY Draconis

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Circumbinary Planets and the SOLARIS Project

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Tracking spin-axis orbital alignment in selected binary systems: the Torun Rossiter–McLaughlin effect survey

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