scholarly journals Resolving blended radial velocities

2010 ◽  
Vol 6 (S276) ◽  
pp. 549-550
Author(s):  
Alexandre Santerne ◽  
Claire Moutou ◽  
François Bouchy ◽  
Keyword(s):  
Radial Velocity ◽  
Radial Velocities ◽  
Eclipsing Binaries ◽  
Brown Dwarf ◽  
True Nature ◽  
Eclipsing Binary ◽  
Transiting Planets

AbstractIn space, photometric surveys are very efficient to detect small transiting planets or stars which are contaminated by blended eclipsing binaries. We present some simulations compared to radial velocity (RV) observations obtained with the SOPHIE spectrograph (OHP, France) in order to determine the true nature of a brown dwarf candidate revealed by CoRoT: a background eclipsing binary diluted by a foreground star.

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 Timing Detection of Eclipsing Binary Planets and Transiting Extrasolar Moons

2004 ◽  
Vol 213 ◽  
pp. 80-84 ◽  
Author(s):  
Laurance R. Doyle ◽  
Hans-Jörg Deeg
Keyword(s):  
Extrasolar Planets ◽  
Eclipsing Binaries ◽  
Eclipsing Binary ◽  
Transiting Planets

We investigate the improved detection of extrasolar planets around eclipsing binaries using eclipse minima timing and extrasolar moons around transiting planets using transit timing offered by the upcoming COROT (ESA, 2005), Kepler (NASA, 2007), and Eddington (ESA 2008) spacecraft missions. Hundreds of circum-binary planets should be discovered and a thorough survey of moons around transiting planets will be accomplished by these missions.

scholarly journals Determining the true mass of radial-velocity exoplanets with Gaia

2020 ◽  
Vol 645 ◽  
pp. A7
Author(s):  
F. Kiefer ◽  
G. Hébrard ◽  
A. Lecavelier des Etangs ◽  
E. Martioli ◽  
S. Dalal ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Extreme Values ◽  
Minimum Mass ◽  
Brown Dwarf ◽  
True Nature ◽  
Astronomical Object ◽  
Orbital Periods ◽  
True Mass

Mass is one of the most important parameters for determining the true nature of an astronomical object. Yet, many published exoplanets lack a measurement of their true mass, in particular those detected as a result of radial-velocity (RV) variations of their host star. For those examples, only the minimum mass, or m sin i, is known, owing to the insensitivity of RVs to the inclination of the detected orbit compared to the plane of the sky. The mass that is given in databases is generally that of an assumed edge-on system (~90°), but many other inclinations are possible, even extreme values closer to 0° (face-on). In such a case, the mass of the published object could be strongly underestimated by up to two orders of magnitude. In the present study, we use GASTON, a recently developed tool taking advantage of the voluminous Gaia astrometric database to constrain the inclination and true mass of several hundreds of published exoplanet candidates. We find nine exoplanet candidates in the stellar or brown dwarf (BD) domain, among which six were never characterized. We show that 30 Ari B b, HD 141937 b, HD 148427 b, HD 6718 b, HIP 65891 b, and HD 16760 b have masses larger than 13.5 MJ at 3σ. We also confirm the planetary nature of 27 exoplanets, including HD 10180 c, d and g. Studying the orbital periods, eccentricities, and host-star metallicities in the BD domain, we found distributions with respect to true masses consistent with other publications. The distribution of orbital periods shows of a void of BD detections below ~100 d, while eccentricity and metallicity distributions agree with a transition between BDs similar to planets and BDs similar to stars in the range 40–50 MJ.

scholarly journals NGTS and WASP photometric recovery of a single-transit candidate from TESS

2019 ◽  
Author(s):  
Samuel Gill ◽  
Daniel Bayliss ◽  
Benjamin F Cooke ◽  
Peter J Wheatley ◽  
Louise D Nielsen ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Stellar Evolution ◽  
Orbital Period ◽  
Eclipsing Binaries ◽  
Dwarf Star ◽  
Velocity Measurements ◽  
Eclipsing Binary ◽  
Long Period ◽  
M Dwarf

Abstract The Transiting Exoplanet Survey Satellite (TESS) produces a large number of single-transit event candidates, since the mission monitors most stars for only ∼27 days. Such candidates correspond to long-period planets or eclipsing binaries. Using the TESS Sector 1 full-frame images, we identified a 7750 ppm single-transit event with a duration of 7 hours around the moderately evolved F-dwarf star TIC-238855958 (Tmag=10.23, Teff=6280±85 K). Using archival WASP photometry we constrained the true orbital period to one of three possible values. We detected a subsequent transit-event with NGTS, which revealed the orbital period to be 38.20 d. Radial velocity measurements from the CORALIE Spectrograph show the secondary object has a mass of M2= 0.148 ± 0.003 M⊙, indicating this system is an F-M eclipsing binary. The radius of the M-dwarf companion is R2 = 0.171 ± 0.003 R⊙, making this one of the most well characterised stars in this mass regime. We find that its radius is 2.3-σ lower than expected from stellar evolution models.

scholarly journals Analysis of the Eclipsing Binaries in the LMC Discovered by OGLE: Period Distribution and Frequency of the Short–Period Binaries

2006 ◽  
Vol 2 (S240) ◽  
pp. 230-235
Author(s):  
Tsevi Mazeh ◽  
Omer Tamuz ◽  
Pierre North
Keyword(s):  
Radial Velocity ◽  
Main Sequence ◽  
Eclipsing Binaries ◽  
Selection Effects ◽  
Eclipsing Binary ◽  
B Stars ◽  
Automated Algorithm ◽  
Period Distribution ◽  
Short Period ◽  
Flat Distribution

AbstractWe review the results of our analysis of the OGLE LMC eclipsing binaries (Mazeh, Tamuz & North 2006), using EBAS — Eclipsing Binary Automated Solver, an automated algorithm to fit lightcurves of eclipsing binaries (Tamuz, Mazeh & North 2006). After being corrected for observational selection effects, the set of detected eclipsing binaries yielded the period distribution and the frequency of all LMC short-period binaries, and not just the eclipsing systems. Somewhat surprisingly, the period distribution is consistent with a flat distribution in logP between 2 and 10 days. The total number of binaries with periods shorter than 10 days in the LMC was estimated to be about 5000. This figure led us to suggest that (0.7± 0.4)% of the main-sequence A- and B-type stars are found in binaries with periods shorter than 10 days. This frequency is substantially smaller than the fraction of binaries found by smaller radial-velocity surveys of Galactic B stars.

scholarly journals Measuring Radial Velocities of Low Mass Eclipsing Binaries

2011 ◽  
Vol 7 ◽  
Author(s):  
Rebecca E Rattray ◽  
Leslie Hebb ◽  
Keivan G Stassun
Keyword(s):  
Radial Velocity ◽  
Correlation Method ◽  
Radial Velocities ◽  
Eclipsing Binaries ◽  
Type Star ◽  
Complex Nature ◽  
Echelle Spectrograph ◽  
Primary Star ◽  
Low Mass ◽  
The Masses

Due to the complex nature of the spectra of low-mass M type stars, it is difficult to determine their metallicities and temperatures directly. By studying eclipsing binary pairs comprising one F, G, or K type star with an M type star, we are able to use what we know about the primary star to learn more about the secondary star. Measuring the orbital reflex motion of the primary star, together with the eclipse light curve of the M star as it transits the primary star, allows us to determine the mass, radius, temperature, and metallicity of the M star. We studied 23 low mass eclipsing binaries (EBLMs) previously discovered by SuperWASP photometry. We obtained spectra using the Cerro Tololo Inter-American Observatory (CTIO) SMARTS 1.5-meter echelle spectrograph between June 2009 and January 2011. Each EBLM target was typically observed ~8 times over this time period. The spectra were processed using standard astronomical software, and a cross-correlation method was used to measure the radial velocity of the target star at each observed epoch. Radial velocities were successfully determined for 21 of the 23 EBLM target objects. Orbital periods, radial velocity amplitudes, and eccentricities for these EBLMs could be determined from these radial velocities together with the preexisting light curves. Using these values and by assuming a mass for the primary star, we will be able to calculate the masses of the secondary M type star in each EBLM system.

scholarly journals Precision radial velocities of double-lined binary stars and the spectroscopic follow-up of circumbinary transiting planet candidates

2008 ◽  
Vol 4 (S253) ◽  
pp. 141-147 ◽  
Author(s):  
Maciej Konacki
Keyword(s):  
Radial Velocity ◽  
Binary Stars ◽  
Radial Velocities ◽  
Eclipsing Binary ◽  
Iodine Cell ◽  
Eclipsing Binary Stars ◽  
Spectroscopic Binary ◽  
Better Than ◽  
Circumbinary Planets

AbstractWe present a new iodine cell based approach that allows one to obtain radial velocities of the components of double-lined spectroscopic binary stars (SB2s) with a precision reaching 5 m/s. Such an RV precision is up to 100 times better than what is currently available in the literature for the SB2s. We discuss the applications of our method to the radial velocity searches for circumbinary planets and spectroscopic follow-up of transiting planet candidates around eclipsing binary stars.

scholarly journals A hundred new eclipsing binary system candidates studied in a near-infrared window in the VVV survey

2020 ◽  
Vol 37 ◽  
Author(s):  
L. V. Gramajo ◽  
T. Palma ◽  
D. Minniti ◽  
R. K. Saito ◽  
J. J. Clariá ◽  
...  
Keyword(s):  
Near Infrared ◽  
Galactic Disk ◽  
Extensive Study ◽  
Eclipsing Binaries ◽  
Physical Parameters ◽  
Eclipsing Binary ◽  
Mean Values ◽  
Median Period ◽  
First Results ◽  
Contact Binaries

Abstract We present the first results obtained from an extensive study of eclipsing binary (EB) system candidates recently detected in the VISTA Variables in the Vía Láctea (VVV) near-infrared (NIR) Survey. We analyse the VVV tile d040 in the southern part of the Galactic disc wherein the interstellar reddening is comparatively low, which makes it possible to detect hundreds of new EB candidates. We present here the light curves and the determination of the geometric and physical parameters of the best candidates found in this ‘NIR window’, including 37 contact, 50 detached, and 13 semi-detached EB systems. We infer that the studied systems have an average of the $K_s$ amplitudes of $0.8$ mag and a median period of 1.22 days where, in general, contact binaries have shorter periods. Using the ‘Physics Of Eclipsing Binaries’ (PHOEBE) interactive interface, which is based on the Wilson and Devinney code, we find that the studied systems have low eccentricities. The studied EBs present mean values of about 5 700 and 4 900 K for the $T_1$ and $T_2$ components, respectively. The mean mass ratio (q) for the contact EB stars is $\sim$ 0.44. This new galactic disk sample is a first look at the massive study of NIR EB systems.

scholarly journals Astrometric Radial Velocities From Hipparcos

1998 ◽  
Vol 11 (1) ◽  
pp. 564-564
Author(s):  
D. Dravins ◽  
L. Lindegren ◽  
S. Madsen ◽  
J. Holmberg
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Radial Velocities ◽  
Radial Motion ◽  
Spectral Lines ◽  
Parallel Program ◽  
Stellar Surface ◽  
Space Astrometry ◽  
Stellar Motion ◽  
Surface Convection

Abstract Space astrometry now permits accurate determinations of stellar radial motion, without using spectroscopy. Although the feasibility of deducing astrometric radial velocities from geometric projection effects was realized already by Schlesinger (1917), only with Hipparcos has it become practical. Such a program has now been carried out for the moving clusters of Ursa Major, Hyades, and Coma Berenices. Realized inaccuracies reach about 300 m/s (Dravins et al. 1997). Discrepancies between astrometric and spectroscopic radial velocities reveal effects (other than stellar motion) that affect wavelength positions of spectral lines. Such are caused by stellar surface convection, and by gravitational redshifts. A parallel program (Gullberg & Dravins 1997) is analyzing high-precision spectroscopic radial velocities for different spectral lines in these stars, using the ELODIE radial-velocity instrument atHaute-Provence.

Sign in / Sign up

Export Citation Format

Share Document