scholarly journals TESS exoplanet candidates validated with HARPS archival data

2019 ◽  
Vol 622 ◽  
pp. L7 ◽  
Author(s):  
Trifon Trifonov ◽  
Jan Rybizki ◽  
Martin Kürster
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Planetary Systems ◽  
Archival Data ◽  
Velocity Analysis ◽  
Orbital Parameters ◽  
Mean Motion ◽  
Two Systems ◽  
Made In ◽  
Mean Motion Resonance

Aims. We aim at the discovery of new planetary systems by exploiting the transit light-curve results from observations made in TESS orbital observatory Sectors 1 and 2 and validating them with precise Doppler measurements obtained from archival HARPS data. Methods. Taking advantage of the reported TESS transit events around GJ 143 (TOI 186) and HD 23472 (TOI 174), we modeled their HARPS precise Doppler measurements and derived orbital parameters for these two systems. Results. For the GJ 143 system, TESS has reported only a single transit, and thus its period is unconstrained from photometry. Our radial velocity analysis of GJ 143 reveals the full Keplerian solution of the system, which is consistent with an eccentric planet with a mass almost twice that of Neptune and a period of Pb = 35.59−0.1+0.1 days. Our estimates of the GJ 143 b planet are fully consistent with the transit timing from TESS. We confirm the two-planet system around HD 23472, which according to our analysis is composed of two Neptune-mass planets in a possible 5:3 mean motion resonance.

scholarly journals Measuring the Orbital Parameters of Radial Velocity Systems in Mean-motion Resonance: A Case Study of HD 200964

2019 ◽  
Vol 158 (4) ◽  
pp. 136
Author(s):  
M. M. Rosenthal ◽  
W. Jacobson-Galan ◽  
B. Nelson ◽  
R. A. Murray-Clay ◽  
J. A. Burt ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Orbital Parameters ◽  
Mean Motion ◽  
Mean Motion Resonance

scholarly journals Analysis of near-separatrix motion in planetary systems

2007 ◽  
Vol 3 (S249) ◽  
pp. 491-498
Author(s):  
Su Wang ◽  
Ji-Lin Zhou
Keyword(s):  
Planetary Systems ◽  
Scattering Model ◽  
High Occurrence ◽  
Mean Motion ◽  
Accretion Process ◽  
Three Body ◽  
Mean Motion Resonance

AbstractNear-separatrix motion is a kind of motion of two planets with their relative apsidal longitude near the boundary between libration and circulation. Observed multiple planetary systems seem to favor near-separatrix motions between neighboring planets. In this report, we study the probability that near-separatrix motion occurs with both the linear secular system and full three-body systems. We find that generally the ratio of near-separatrix motion is small unless the eccentricities of the two planets differ from each other by an order of magintude, or they are in mean motion resonance. To explore the dynamical procedures causing the near-separatrix motion, we suppose a modification to scattering model by adding a mass-accretion process during the protoplanet growth. Statistics on the modified scattering model indicate that the probability of the final planet pairs in near-separatrix motion is high (∼ 85%), which may explain the high occurrence of near-separatrix motions in observed planetary systems.

scholarly journals Fluorescence and Chromospheric Activity of V471 Tau

2002 ◽  
Vol 187 ◽  
pp. 167-172
Author(s):  
T.R. Vaccaro ◽  
R.E. Wilson
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Star ◽  
Star Model ◽  
Orbital Inclination ◽  
Orbital Parameters ◽  
Maximum Emission ◽  
Chromospheric Activity

AbstractThe red dwarf + white dwarf eclipsing binary V471 Tau shows a variable Hα feature that varies from absorption during eclipse to maximum emission during white dwarf transit. In 1998 we obtained simultaneous BVRI photometry and Hα spectroscopy, with thorough phase coverage of the 12.5 hour orbital period. A binary star model was used with our light curve, radial velocity, and Hα data to refine stellar and orbital parameters. Combined absorption-emission profiles were generated by the model and fit to the observations, yielding a red star radius of 0.94R⊙. Orbital inclination 78° is required with this size and other known parameters. The model includes three spots 1,000 K cooler than the surrounding photosphere. The variable Hα profile was modeled as a chromospheric fluorescing region (essentially on the surface of the red star) centered at the substellar point. Additional emission seen outside our modeled profiles may be large co-rotating prominences that complicate the picture.

scholarly journals What to Expect from Transiting Multiplanet Systems

2008 ◽  
Vol 4 (S253) ◽  
pp. 173-179 ◽  
Author(s):  
Daniel C. Fabrycky
Keyword(s):  
Radial Velocity ◽  
Transit Time ◽  
Dynamical Evolution ◽  
Velocity Measurements ◽  
Search Methods ◽  
Tidal Evolution ◽  
Transiting Planets ◽  
Mean Motion ◽  
Time Variations ◽  
Mean Motion Resonance

AbstractSo far radial velocity measurements have discovered ~25 stars to host multiple planets. The statistics imply that many of the known hosts of transiting planets should have additional planets, yet none have been solidly detected. They will be soon, via complementary search methods of RV, transit-time variations of the known planet, and transits of the additional planet. When they are found, what can transit measurements add to studies of multiplanet dynamical evolution? First, mutual inclinations become measurable, for comparison to the solar system's disk-like configuration. Such measurements will give important constraints to planet-planet scattering models, just as the radial velocity measurements of eccentricity have done. Second, the Rossiter-McLaughlin effect measures stellar obliquity, which can be modified by two-planet dynamics with a tidally evolving inner planet. Third, transit-time variations are exquisitely sensitive to planets in mean motion resonance. Two planets differentially migrating in the disk can establish such resonances, and tidal evolution of the planets can break them, so the configuration and frequency of these resonances as a function of planetary parameters will constrain these processes.

scholarly journals The Configuration Formation of Planetary Systems Observed by Kepler

2012 ◽  
Vol 8 (S293) ◽  
pp. 106-109
Author(s):  
Su Wang ◽  
Jianghui Ji
Keyword(s):  
Star Formation ◽  
Late Stage ◽  
Early Stage ◽  
Planetary Systems ◽  
High Rate ◽  
Mean Motion ◽  
Star Evolution ◽  
Kepler Mission ◽  
Resonant Systems ◽  
Mean Motion Resonance

AbstractThe Kepler mission has found many planetary systems, among them more than 80 systems host three planet candidates which reveal a configuration of near 4:2:1 mean motion resonance. In this paper, we focus on the configuration formation of resonant systems. As shown from our model and N-body simulations, we find that 3:2 mean motion resonance always forms at the early stage of star evolution and planets undergo high rate of migration, while 2:1 mean motion resonance happens at the late stage of the star formation, more often.

scholarly journals The supergiant O + O binary system HD 166734: a new study

2016 ◽  
Vol 12 (S329) ◽  
pp. 402-402 ◽  
Author(s):  
E. Gosset ◽  
L. Mahy ◽  
Y. Damerdji ◽  
C. Nitschelm ◽  
H. Sana ◽  
...  
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Radial Velocity ◽  
Velocity Curve ◽  
Physical Parameters ◽  
Radial Velocity Curve ◽  
X Ray ◽  
Orbital Parameters

AbstractWe present here a modern study of the radial velocity curve and of the photometric light curve of the very interesting supergiant O7.5If + O9I(f) binary system HD 166734. The physical parameters of the stars and the orbital parameters are carefully determined. We also perform the analysis of the observed X-ray light curve of this colliding-wind binary.

scholarly journals Exploiting periodic orbits as dynamical clues for Kepler and K2 systems

2020 ◽  
Vol 640 ◽  
pp. A55
Author(s):  
Kyriaki I. Antoniadou ◽  
Anne-Sophie Libert
Keyword(s):  
Periodic Orbits ◽  
Intrinsic Property ◽  
Orbital Elements ◽  
Orbital Parameters ◽  
Mean Motion ◽  
Extrasolar Systems ◽  
Resonant Systems ◽  
Three Body ◽  
Mean Motion Resonance

Aims. Many extrasolar systems possessing planets in mean-motion resonance or resonant chain have been discovered to date. The transit method coupled with transit timing variation analysis provides an insight into the physical and orbital parameters of the systems, but suffers from observational limitations. When a (near-)resonant planetary system resides in the dynamical neighbourhood of a stable periodic orbit, its long-term stability, and thus survival, can be guaranteed. We use the intrinsic property of the periodic orbits, namely their linear horizontal and vertical stability, to validate or further constrain the orbital elements of detected two-planet systems. Methods. We computed the families of periodic orbits in the general three-body problem for several two-planet Kepler and K2 systems. The dynamical neighbourhood of the systems is unveiled with maps of dynamical stability. Results. Additional validations or constraints on the orbital elements of K2-21, K2-24, Kepler-9, and (non-coplanar) Kepler-108 near-resonant systems were achieved. While a mean-motion resonance locking protects the long-term evolution of the systems K2-21 and K2-24, such a resonant evolution is not possible for the Kepler-9 system, whose stability is maintained through an apsidal anti-alignment. For the Kepler-108 system, we find that the stability of its mutually inclined planets could be justified either solely by a mean-motion resonance, or in tandem with an inclination-type resonance. Going forward, dynamical analyses based on periodic orbits could yield better constrained orbital elements of near-resonant extrasolar systems when performed in parallel to the fitting of the observational data.

scholarly journals WASP light curve of the eclipsing binary VZ CVn

2012 ◽  
pp. 77-82 ◽  
Author(s):  
O. Latkovic
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Eclipsing Binary ◽  
Spectroscopic Parameters ◽  
Orbital Parameters ◽  
Minimum Light ◽  
Photometric Elements ◽  
Modeling Code

The WASP light curve of the eclipsing binary VZ CVn, consisting of more than 14000 individual observations, is analyzed for photometric elements using the modeling code of Djurasevic (1992). The spectroscopic parameters are adopted from the recent radial velocity work by Pribulla et al. (2009). The results of the study include new times of minimum light, an improved ephemeris, and the updated physical and orbital parameters of the system.

Scheduling strategies for the ESPRESSO follow-up of TESS targets

2021 ◽  
Vol 503 (4) ◽  
pp. 5504-5521
Author(s):  
L Cabona ◽  
P T P Viana ◽  
M Landoni ◽  
J P Faria
Keyword(s):  
Radial Velocity ◽  
Planetary Systems ◽  
Data Set ◽  
Noise Component ◽  
Orbital Parameters ◽  
Transiting Planets ◽  
Accuracy And Precision ◽  
Scheduling Strategies ◽  
The Masses

ABSTRACT Radial-velocity follow-up of stars harbouring transiting planets detected by TESS is expected to require very large amounts of expensive telescope time in the next few years. Therefore, scheduling strategies should be implemented to maximize the amount of information gathered about the target planetary systems. We consider myopic and non-myopic versions of a novel uniform-in-phase scheduler, as well as a random scheduler, and compare these scheduling strategies with respect to the bias, accuracy and precision achieved in recovering the mass and orbital parameters of transiting and non-transiting planets. This comparison is carried out based on realistic simulations of radial-velocity follow-up with ESPRESSO of a sample of 50 TESS target stars, with simulated planetary systems containing at least one transiting planet with a radius below 4R⊕. Radial-velocity data sets were generated under reasonable assumptions about their noise component, including that resulting from stellar activity, and analysed using a fully Bayesian methodology. We find the random scheduler leads to a more biased, less accurate, and less precise, estimation of the mass of the transiting exoplanets. No significant differences are found between the results of the myopic and non-myopic implementations of the uniform-in-phase scheduler. With only about 22 radial velocity measurements per data set, our novel uniform-in-phase scheduler enables an unbiased (at the level of 1 per cent) measurement of the masses of the transiting planets, while keeping the average relative accuracy and precision around 16 per cent and 23 per cent, respectively. The number of non-transiting planets detected is similar for all the scheduling strategies considered, as well as the bias, accuracy and precision with which their masses and orbital parameters are recovered.

scholarly journals KEPLER PLANETARY SYSTEMS: DOPPLER BEAMING EFFECT SIGNIFICANCE

2021 ◽  
Vol 57 (1) ◽  
pp. 123-132
Author(s):  
H. Barbier ◽  
E. López
Keyword(s):  
Light Curve ◽  
Radial Velocity ◽  
Observational Data ◽  
Close Agreement ◽  
Extrasolar Planets ◽  
Planetary Systems ◽  
Light Curves ◽  
Third Harmonic ◽  
Good Agreement

In the present work, in order to estimate the semi-amplitude of the radial velocity, we evaluate the contribution of the Doppler beaming effect to the phase curves of the all confirmed extrasolar planets (2776, September 2019), observed so far by the Kepler telescope. By modeling the tiny photometric variations (reflection, ellipsoidal and Doppler beaming effects) of the light curves, we found that the best observational data are in close agreement with the theoretical and published values of the amplitudes only for exoplanets: KOI-13b and TrES-2b. The derived values for the radial velocity also are in good agreement with those published by some authors. Furthermore, we found it necessary to introduce a third harmonic (3Φ) contribution into the KOI-13b and HAT-P7b light curve models, in order to decrease the residuals.

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