scholarly journals Proxima’s orbit around α Centauri

2017 ◽  
Vol 598 ◽  
pp. L7 ◽  
Author(s):  
P. Kervella ◽  
F. Thévenin ◽  
C. Lovis
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Orbital Period ◽  
Triple System ◽  
Orbital Motion ◽  
The Sun ◽  
Proper Motions ◽  
Velocity Measurements ◽  
Degree Of Confidence ◽  
High Degree

Proxima and α Centauri AB have almost identical distances and proper motions with respect to the Sun. Although the probability of such similar parameters is, in principle, very low, the question as to whether they actually form a single gravitationally bound triple system has been open since the discovery of Proxima one century ago. Owing to HARPS high-precision absolute radial velocity measurements and the recent revision of the parameters of the α Cen pair, we show that Proxima and α Cen are gravitationally bound with a high degree of confidence. The orbital period of Proxima is ≈ 550 000 yr. With an eccentricity of 0.50+0.08-0.09, Proxima comes within 4.3+1.1-0.9 kau of α Cen at periastron, and is currently close to apastron (13.0+0.3-0.1 kau). This orbital motion may have influenced the formation or evolution of the recently discovered planet orbiting Proxima, as well as circumbinary planet formation around α Cen.

scholarly journals TOI-222: a single-transit TESS candidate revealed to be a 34-d eclipsing binary with CORALIE, EulerCam, and NGTS

2019 ◽  
Vol 492 (2) ◽  
pp. 1761-1769 ◽  
Author(s):  
Monika Lendl ◽  
François Bouchy ◽  
Samuel Gill ◽  
Louise D Nielsen ◽  
Oliver Turner ◽  
...  
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Orbital Period ◽  
Mass Star ◽  
Mass Determination ◽  
Velocity Measurements ◽  
Eclipsing Binary ◽  
Photometric Detection ◽  
Long Period ◽  
Low Mass

ABSTRACT We report the period, eccentricity, and mass determination for the Transiting Exoplanet Survey Satellite (TESS) single-transit event candidate TOI-222, which displayed a single 3000 ppm transit in the TESS 2-min cadence data from Sector 2. We determine the orbital period via radial velocity measurements (P = 33.9 d), which allowed for ground-based photometric detection of two subsequent transits. Our data show that the companion to TOI-222 is a low-mass star, with a radius of $0.18_{-0.10}^{+0.39}$ R⊙ and a mass of 0.23 ± 0.01 M⊙. This discovery showcases the ability to efficiently discover long-period systems from TESS single-transit events using a combination of radial velocity monitoring coupled with high-precision ground-based photometry.

scholarly journals Solar barycentric dynamics from a new solar-planetary ephemeris

2018 ◽  
Vol 615 ◽  
pp. A153 ◽  
Author(s):  
Rodolfo G. Cionco ◽  
Dmitry A. Pavlov
Keyword(s):  
High Precision ◽  
Orbital Motion ◽  
Giant Planets ◽  
Reference Plane ◽  
The Sun ◽  
The Future ◽  
Dynamical Parameters ◽  
Definition Of ◽  
Invariable Plane ◽  
Planetary Theories

Aims. The barycentric dynamics of the Sun has increasingly been attracting the attention of researchers from several fields, due to the idea that interactions between the Sun’s orbital motion and solar internal functioning could be possible. Existing high-precision ephemerides that have been used for that purpose do not include the effects of trans-Neptunian bodies, which cause a significant offset in the definition of the solar system’s barycentre. In addition, the majority of the dynamical parameters of the solar barycentric orbit are not routinely calculated according to these ephemerides or are not publicly available. Methods. We developed a special version of the IAA RAS lunar–solar–planetary ephemerides, EPM2017H, to cover the whole Holocene and 1 kyr into the future. We studied the basic and derived (e.g., orbital torque) barycentric dynamical quantities of the Sun for that time span. A harmonic analysis (which involves an application of VSOP2013 and TOP2013 planetary theories) was performed on these parameters to obtain a physics-based interpretation of the main periodicities present in the solar barycentric movement. Results. We present a high-precision solar barycentric orbit and derived dynamical parameters (using the solar system’s invariable plane as the reference plane), widely accessible for the whole Holocene and 1 kyr in the future. Several particularities and barycentric phenomena are presented and explained on dynamical bases. A comparison with the Jet Propulsion Laboratory DE431 ephemeris, whose main differences arise from the modelling of trans-Neptunian bodies, shows significant discrepancies in several parameters (i.e., not only limited to angular elements) related to the solar barycentric dynamics. In addition, we identify the main periodicities of the Sun’s barycentric movement and the main giant planets perturbations related to them.

scholarly journals Densified Pupil Spectrograph as High-precision Radial Velocimetry: From Direct Measurement of the Universe’s Expansion History to Characterization of Nearby Habitable Planet Candidates

2022 ◽  
Vol 163 (2) ◽  
pp. 63
Author(s):  
Taro Matsuo ◽  
Thomas P. Greene ◽  
Mahdi Qezlou ◽  
Simeon Bird ◽  
Kiyotomo Ichiki ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Direct Measurement ◽  
High Precision ◽  
Resolving Power ◽  
Line Of Sight ◽  
High Dispersion ◽  
Velocity Measurements ◽  
Habitable Planet ◽  
Airy Disk

Abstract The direct measurement of the universe’s expansion history and the search for terrestrial planets in habitable zones around solar-type stars require extremely high-precision radial-velocity measures over a decade. This study proposes an approach for enabling high-precision radial-velocity measurements from space. The concept presents a combination of a high-dispersion densified pupil spectrograph and a novel line-of-sight monitor for telescopes. The precision of the radial-velocity measurements is determined by combining the spectrophotometric accuracy and the quality of the absorption lines in the recorded spectrum. Therefore, a highly dispersive densified pupil spectrograph proposed to perform stable spectroscopy can be utilized for high-precision radial-velocity measures. A concept involving the telescope’s line-of-sight monitor is developed to minimize the change of the telescope’s line of sight over a decade. This monitor allows the precise measurement of long-term telescope drift without any significant impact on the Airy disk when the densified pupil spectra are recorded. We analytically derive the uncertainty of the radial-velocity measurements, which is caused by the residual offset of the lines of sight at two epochs. We find that the error could be reduced down to approximately 1 cm s−1, and the precision will be limited by another factor (e.g., wavelength calibration uncertainty). A combination of the high-precision spectrophotometry and the high spectral resolving power could open a new path toward the characterization of nearby non-transiting habitable planet candidates orbiting late-type stars. We present two simple and compact highly dispersed densified pupil spectrograph designs for cosmology and exoplanet sciences.

Investigation of relative motion in the triple system ADS 48 on the basis of Gaia DR2 and Pulkovo 26-inch refractor observations

2021 ◽  
pp. 89-98
Author(s):  
O. V. KIYAEVA ◽  
R. YA. ZHUCHKOV ◽  
I.S. IZMAILOV
Keyword(s):  
High Precision ◽  
Relative Motion ◽  
Apparent Motion ◽  
Triple System ◽  
Radial Velocities ◽  
Proper Motions ◽  
The Family ◽  
Outer Pair ◽  
Motion Parameters ◽  
Gaia Dr2

There are high-precision positions, proper motions, parallaxes and radial velocities at the instant 2015.5 for all three components of the star ADS 48 ABF in the catalogue Gaia DR2 (2018). According to these data relative motions and the family of orbits were calculated by the Apparent Motion Parameters (AMP) method (Kiselev and Kiyaeva, 1980), and the best orbit was chosen for the inner pair AB. A perturbation with the period of 11 years was discovered according to Pulkovo observations of the outer pair. The reasons for the perturbation are discussed.

High Velocity Spectroscopic Binary Orbits from Photoelectric Radial Velocities: BD+20 5152, a Possible Triple System

2010 ◽  
Vol 19 (3-4) ◽  
Author(s):  
J. Sperauskas ◽  
A. Bartkevičius ◽  
R. P. Boyle ◽  
V. Deveikis
Keyword(s):  
Radial Velocity ◽  
Proper Motion ◽  
High Velocity ◽  
Triple System ◽  
Mass Velocity ◽  
Center Of Mass ◽  
Primary Component ◽  
Eccentric Orbit ◽  
Velocity Measurements ◽  
Spectroscopic Binary

AbstractThe spectroscopic orbit of a high proper motion star, BD+20 5152, is calculated from 34 CORAVEL-type radial velocity measurements. The star has a slightly eccentric orbit with a period of 5.70613 d, half-amplitude of 47.7 km/s and eccentricity of 0.049. The center-of-mass velocity of the system is -24.3 km/s. BD+20 5152 seems to be a triple system consisting of a G8 dwarf as a primary component and of two K6-M0 dwarfs as secondary and tertiary components. This model is based on the analysis of its UBVRI and JHK magnitudes. According to the SuperWASP photometry, spots on the surface of the primary are suspected. The excessive brightness in the Galex FUV and NUV magnitudes and a non-zero eccentricity suggest the age of this system to be less than 1 Gyr.

scholarly journals Phase connected X-ray light curve and He II radial velocity measurements of NGC 300 X-1

2018 ◽  
Vol 14 (S346) ◽  
pp. 187-192
Author(s):  
S. Carpano ◽  
F. Haberl ◽  
P. Crowther ◽  
A. Pollock
Keyword(s):  
Black Hole ◽  
Light Curve ◽  
Radial Velocity ◽  
Orbital Period ◽  
High Mass ◽  
Velocity Measurements ◽  
X Ray ◽  
Black Hole Radiation ◽  
Ic 10 ◽  
Binary Evolution

Abstract. NGC 300 X-1 and IC 10 X-1 are currently the only two robust extragalactic candidates for being Wolf-Rayet/black hole X-ray binaries, the Galactic analogue being Cyg X-3. These systems are believed to be a late product of high-mass X-ray binary evolution and direct progenitors of black hole mergers. From the analysis of Swift data, the orbital period of NGC 300 X-1 was found to be 32.8 h. We here merge the full set of existing data of NGC 300 X-1, using XMM-Newton, Chandra and Swift observations to derive a more precise value of the orbital period of 32.7932 ± 0.0029 h above a confidence level of 99.99%. This allows us to phase connect the X-ray light curve of the source with radial velocity measurements of He II lines performed in 2010. We show that, as for IC 10 X-1 and Cyg X-3, the X-ray eclipse corresponds to maximum of the blueshift of the He II lines, instead of the expected zero velocity. This indicates that for NGC 300 X-1 as well, the wind of the WR star is completely ionised by the black hole radiation and that the emission lines come from the region of the WR star that is in the shadow. We also present for the first time the light curve of two recent very long XMM-Newton observations of the source, performed on the 16th to 20th of December 2016.

scholarly journals Search for Low-Mass Planets Around Late-M Dwarfs Using IRD

2012 ◽  
Vol 8 (S293) ◽  
pp. 201-203
Author(s):  
Masashi Omiya ◽  
Bun'ei Sato ◽  
Hiroki Harakawa ◽  
Masayuki Kuzuhara ◽  
Teruyuki Hirano ◽  
...  
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Near Infrared ◽  
Frequency Comb ◽  
Habitable Zone ◽  
Velocity Measurements ◽  
M Dwarfs ◽  
Low Mass ◽  
Rocky Planets ◽  
Theoretical Simulations

AbstractWe have a plan to conduct a Doppler planet search for low-mass planets around nearby middle-to-late M dwarfs using IRD. IRD is the near-infrared high-precision radial velocity instrument for the Subaru 8.2-m telescope. We expect to achieve the accuracy of the radial velocity measurements of 1 m/s using IRD with a frequency comb as a wavelengh calibrator. Thus, we would detect super-Earths in habitable zone and low-mass rocky planets in close-in orbits around late-M dwarfs. In this survey, we aim to understand and discuss statistical properties of low-mass planets around low-mass M dwarfs compared with those derived from theoretical simulations.

Charge Transfer Inefficiency effect for high-precision radial velocity measurements

2009 ◽  
Vol 37 ◽  
pp. 247-253 ◽  
Author(s):  
F. Bouchy ◽  
J. Isambert ◽  
C. Lovis ◽  
I. Boisse ◽  
P. Figueira ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Radial Velocity ◽  
High Precision ◽  
Velocity Measurements

scholarly journals Towards a fully automated eclipsing binary solver for Gaia

2008 ◽  
Vol 4 (S253) ◽  
pp. 402-403
Author(s):  
Brandon Tingley ◽  
Gilles Sadowski ◽  
Christos Siopis
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
Graphical Interface ◽  
Velocity Measurements ◽  
New Approach ◽  
Eclipsing Binary ◽  
Photometric Observations

AbstractGaia, an ESA cornerstone mission, will obtain of the order of 100 high-precision photometric observations and lower precision radial velocity measurements over five years for around a billion stars – several hundred thousand of which will be eclipsing binaries. In order to extract the characteristics of these systems, a fully automated code must be available. During the process of this development, two tools that may be of use to the transit community have emerged: a very fast, simple, detached eclipsing binary simulator/solver based on a new approach and an interacting eclipsing binary simulator with most of the features of the Wilson-Devinney and Nightfall codes, but fully documented and written in easy-to-follow and highly portable Java. Currently undergoing development and testing, this code includes an intuitive graphical interface and an optimizer for the estimation of the physical parameters of the system.

scholarly journals Dynamical investigations of the multiple stars

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
Olga V. Kiyaeva ◽  
Roman Ya. Zhuchkov
Keyword(s):  
High Precision ◽  
Orbital Period ◽  
Triple System ◽  
Main Sequence ◽  
Double Star ◽  
Multiple Stars ◽  
Ccd Observations ◽  
Triple Star

AbstractTwo multiple stars - the quadruple star - Bootis (ADS 9173) and the triple star T Taury were investigated. The visual double star - Bootiswas studied on the basis of the Pulkovo 26-inch refractor observations 1982-2013. An invisible satellite of the component A was discovered due to long-term uniform series of observations. Its orbital period is 20 ± 2 years. The known invisible satellite of the component B with near 5 years period was confirmed due to high precision CCD observations. The astrometric orbits of the both components were calculated. The orbits of inner and outer pairs of the pre-main sequence binary T Taury were calculated on the basis of high precision observations by the VLT and on the Keck II Telescope. This weakly hierarchical triple system is stable with probability more than 70%.

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