scholarly journals The TESS-Keck Survey. VIII. Confirmation of a Transiting Giant Planet on an Eccentric 261 Day Orbit with the Automated Planet Finder Telescope*

2022 ◽  
Vol 163 (2) ◽  
pp. 61
Author(s):  
Paul A. Dalba ◽  
Stephen R. Kane ◽  
Diana Dragomir ◽  
Steven Villanueva ◽  
Karen A. Collins ◽  
...  
Keyword(s):  
Orbital Period ◽  
Giant Planet ◽  
Giant Planets ◽  
Orbital Eccentricity ◽  
Exciting Potential ◽  
Tentative Evidence ◽  
Orbital Periods ◽  
Low Irradiation ◽  
Transit Method

Abstract We report the discovery of TOI-2180 b, a 2.8 M J giant planet orbiting a slightly evolved G5 host star. This planet transited only once in Cycle 2 of the primary Transiting Exoplanet Survey Satellite (TESS) mission. Citizen scientists identified the 24 hr single-transit event shortly after the data were released, allowing a Doppler monitoring campaign with the Automated Planet Finder telescope at Lick Observatory to begin promptly. The radial velocity observations refined the orbital period of TOI-2180 b to be 260.8 ± 0.6 days, revealed an orbital eccentricity of 0.368 ± 0.007, and discovered long-term acceleration from a more distant massive companion. We conducted ground-based photometry from 14 sites spread around the globe in an attempt to detect another transit. Although we did not make a clear transit detection, the nondetections improved the precision of the orbital period. We predict that TESS will likely detect another transit of TOI-2180 b in Sector 48 of its extended mission. We use giant planet structure models to retrieve the bulk heavy-element content of TOI-2180 b. When considered alongside other giant planets with orbital periods over 100 days, we find tentative evidence that the correlation between planet mass and metal enrichment relative to stellar is dependent on orbital properties. Single-transit discoveries like TOI-2180 b highlight the exciting potential of the TESS mission to find planets with long orbital periods and low irradiation fluxes despite the selection biases associated with the transit method.

scholarly journals The Relation between Spin and Orbital Periods in HMXBs

2003 ◽  
Vol 214 ◽  
pp. 215-217
Author(s):  
Q. Z. Liu ◽  
X. D. Li ◽  
D. M. Wei
Keyword(s):  
Magnetic Fields ◽  
Orbital Period ◽  
Critical Line ◽  
High Mass ◽  
Orbital Eccentricity ◽  
X Ray ◽  
Spin Period ◽  
Orbital Periods ◽  
X Ray Binaries

The relation between the spin period (Ps) and the orbital period (Po) in high-mass X-ray binaries (HMXBs) is investigated. In order for Be/X-ray binaries to locate above the critical line of observable X-ray emission due to accretion, it is necessary for an intermediate orbital eccentricity to be introduced. We suggest that some peculiar systems in the Po − Ps diagram are caused by their peculiar magnetic fields.

scholarly journals Two bodies with high eccentricity around the cataclysmic variable QS Vir

2010 ◽  
Vol 6 (S276) ◽  
pp. 495-496 ◽  
Author(s):  
Leonardo A. Almeida ◽  
Francisco Jablonski
Keyword(s):  
Orbital Period ◽  
Giant Planet ◽  
Cataclysmic Variable ◽  
Brown Dwarf ◽  
Period Variations ◽  
Angular Momentum Loss ◽  
Best Fitting ◽  
Orbital Periods ◽  
The Masses ◽  
Two Bodies

AbstractQS Vir is an eclipsing cataclysmic variable with 3.618 hrs orbital period. This system has the interesting characteristics that it does not show mass transfer between the components through the L1 Lagrangian point and shows a complex orbital period variation history. Qian et al. (2010) associated the orbital period variations to the presence of a giant planet in the system plus angular momentum loss via magnetic braking. Parsons et al. (2010) obtained new eclipse timings and observed that the orbital period variations associated to a hypothetical giant planet disagree with their measurements and concluded that the decrease in orbital period is part of a cyclic variation with period ~16 yrs. In this work, we present 28 new eclipse timings of QS Vir and suggest that the orbital period variations can be explained by a model with two circumbinary bodies. The best fitting gives the lower limit to the masses M1 sin(i) ~ 0.0086 M⊙ and M2 sin(i) ~ 0.054 M⊙; orbital periods P1 ~ 14.4 yrs and P2 ~ 16.99 yrs, and eccentricities e1 ~ 0.62 and e2~0.92 for the two external bodies. Under the assumption of coplanarity among the two external bodies and the inner binary, we obtain a giant planet with ~0.009 M⊙ and a brown dwarf with ~ 0.056 M⊙ around the eclipsing binary QS Vir.

scholarly journals Spectroscopic binaries RV Tauri and DF Cygni

2019 ◽  
Vol 628 ◽  
pp. A40 ◽  
Author(s):  
Rajeev Manick ◽  
Devika Kamath ◽  
Hans Van Winckel ◽  
Alain Jorissen ◽  
Sanjay Sekaran ◽  
...  
Keyword(s):  
Orbital Period ◽  
Asymptotic Giant Branch ◽  
Spectroscopic Binaries ◽  
Spectral Energy ◽  
Pulsation Frequency ◽  
Photometric Variability ◽  
Orbital Inclination ◽  
Orbital Periods ◽  
The Impact

Context. Some RV Tauri stars show a long-term photometric variability in their mean magnitudes. DF Cygni (DF Cyg), the only RV Tauri star in the original Kepler field, and the prototype RV Tauri (RV Tau) are two such stars. Aims. The focus of this paper is on two famous but still poorly understood RV Tauri stars: RV Tau and DF Cyg. We aim to confirm their suspected binary nature and derive their orbital elements to investigate the impact of their orbits on the evolution of these systems. This research is embedded in a wider endeavour to study binary evolution of low- and intermediate-mass stars. Methods. The high amplitude pulsations were cleaned from the radial-velocity data to better constrain the orbital motion, allowing us to obtain accurate orbital parameters. We also analysed the photometric time series of both stars using a Lomb-Scargle periodogram. We used Gaia Data Release 2 (DR2) parallaxes in combination with the spectral energy distributions (SEDs) to compute their luminosities. These luminosities were complemented with the ones we computed using a period-luminosity-colour (PLC) relation for RV Tauri stars. The ratio of the circumstellar infrared (IR) flux to the photospheric flux obtained from the SEDs was used to estimate the orbital inclination of each system. Results. DF Cyg and RV Tau are binaries with spectroscopic orbital periods of 784 ± 16 days and 1198 ± 17 days, respectively. These orbital periods are found to be similar to the long-term periodic variability in the photometry, indicating that binarity indeed explains the long-term photometric variability. The SEDs of these systems indicate the presence of a circumbinary disc. Our line of sight grazes the dusty disc, which causes the photometric flux from the star to extinct periodically with the orbital period. Our derived orbital inclinations enabled us to obtain accurate companion masses for DF Cyg and RV Tau, and these were found to be 0.6 ± 0.1 M⊙ and 0.7 ± 0.1 M⊙, respectively. The derived luminosities suggest that RV Tau is a post asymptotic giant branch (post-AGB) binary, while DF Cyg is likely a post red giant branch (post-RGB) binary. Analysis of the Kepler photometry of DF Cyg revealed a power spectrum with side lobes around the fundamental pulsation frequency. This modulation corresponds to the spectroscopic orbital period and hence to the long-term photometric period. Finally we report on the evidence of high velocity absorption features related to the Hα profile in both objects, indicating outflows launched from around the companion.

scholarly journals A simplified model for the secular dynamics of eccentric discs and applications to planet–disc interactions

2019 ◽  
Vol 490 (3) ◽  
pp. 4353-4365 ◽  
Author(s):  
Jean Teyssandier ◽  
Dong Lai
Keyword(s):  
Evolution Equations ◽  
Giant Planet ◽  
Giant Planets ◽  
Simplified Model ◽  
Secular Resonance ◽  
Secular Dynamics ◽  
Long Time ◽  
Hydrodynamical Simulations ◽  
Self Gravity

ABSTRACT We develop a simplified model for studying the long-term evolution of giant planets in protoplanetary discs. The model accounts for the eccentricity evolution of the planets and the dynamics of eccentric discs under the influences of secular planet–disc interactions and internal disc pressure, self-gravity, and viscosity. Adopting the ansatz that the disc precesses coherently with aligned apsides, the eccentricity evolution equations of the planet–disc system reduce to a set of linearized ordinary differential equations, which allows for fast computation of the evolution of planet–disc eccentricities over long time-scales. Applying our model to ‘giant planet + external disc’ systems, we are able to reproduce and explain the secular behaviours found in previously published hydrodynamical simulations. We re-examine the possibility of eccentricity excitation (due to secular resonance) of multiple planets embedded in a dispersing disc, and find that taking into account the dynamics of eccentric discs can significantly affect the evolution of the planets’ eccentricities.

Dynamical influence of a wide binary companion on giant planet migration

2020 ◽  
Author(s):  
Arnaud Roisin ◽  
Anne-Sophie Libert
Keyword(s):  
Binary Star ◽  
Giant Planet ◽  
Giant Planets ◽  
Wide Binary ◽  
Multiple Star ◽  
Stellar Component ◽  
Hydrodynamical Simulations ◽  
Self Gravity ◽  
Kozai Resonance

<p>About half of the Sun-like stars are part of multiple-star systems. To date more than 100 planets are known moving around one stellar component of a binary star (S-type planets), with diverse eccentricities. These discoveries raise the question of their formation and long-term evolution, since the stellar companion can strongly affect the planet formation process. Here we study the dynamical influence of a wide binary companion on the (Type-II) migration of a single giant planet in the protoplanetary disk. Using a modified version of an N-body integrator adapted for binary star systems and adopting eccentricity and inclination damping formulae (derived from hydrodynamical simulations) to properly model the influence of the disk, we carried out more than 3500 numerical simulations with different initial configurations and study the dynamics of the systems up to 100 Myr. Particular attention is paid to the Lidov-Kozai resonance whose role is determinant for the evolution of the giant planet, although initially embedded in the disk, when the stellar companion is highly inclined. We highlight the high probability for the planet of experiencing, during the disk phase, a scattering event or an ejection due to the presence of the binary companion. We also show that a capture of the migrating planet in the Lidov-Kozai resonance is far from being automatic even when the binary companion is highly inclined, since only 10% of the systems actually end up in the resonance. Nevertheless, using a simplified quadrupolar hamiltonian approach, we point out that, for highly inclined binary companions, the dynamical evolutions are strongly affected by the Lidov-Kozai resonance islands, which create the pile-ups observed around – but not centred on – the pericenter values of 90° and 270° in the final distribution of the giant planets. The influence of the self-gravity of the disk on the previous results is finally discussed.</p>

scholarly journals Formation of hot Jupiters through secular chaos and dynamical tides

2019 ◽  
Vol 486 (2) ◽  
pp. 2265-2280 ◽  
Author(s):  
Jean Teyssandier ◽  
Dong Lai ◽  
Michelle Vick
Keyword(s):  
Semimajor Axis ◽  
Giant Planet ◽  
Giant Planets ◽  
Orbital Energy ◽  
High Eccentricity ◽  
Hot Jupiters ◽  
Orbital Decay ◽  
Short Period ◽  
Orbital Periods ◽  
Hot Jupiter

Abstract The population of giant planets on short-period orbits can potentially be explained by some flavours of high-eccentricity migration. In this paper, we investigate one such mechanism involving ‘secular chaos’, in which secular interactions between at least three giant planets push the inner planet to a highly eccentric orbit, followed by tidal circularization and orbital decay. In addition to the equilibrium tidal friction, we incorporate dissipation due to dynamical tides that are excited inside the giant planet. Using the method of Gaussian rings to account for planet–planet interactions, we explore the conditions for extreme eccentricity excitation via secular chaos and the properties of hot Jupiters formed in this migration channel. Our calculations show that once the inner planet reaches a sufficiently large eccentricity, dynamical tides quickly dissipate the orbital energy, producing an eccentric warm Jupiter, which then decays in semimajor axis through equilibrium tides to become a hot Jupiter. Dynamical tides help the planet avoid tidal disruption, increasing the chance of forming a hot Jupiter, although not all planets survive the process. We find that the final orbital periods generally lie in the range of 2–3 d, somewhat shorter than those of the observed hot Jupiter population. We couple the planet migration to the stellar spin evolution to predict the final spin-orbit misalignments. The distribution of the misalignment angles we obtain shows a lack of retrograde orbits compared to observations. Our results suggest that high-eccentricity migration via secular chaos can only account for a fraction of the observed hot Jupiter population.

scholarly journals Two Massive Jupiters in Eccentric Orbits from the TESS Full-frame Images

2021 ◽  
Vol 163 (1) ◽  
pp. 9
Author(s):  
Mma Ikwut-Ukwa ◽  
Joseph E. Rodriguez ◽  
Samuel N. Quinn ◽  
George Zhou ◽  
Andrew Vanderburg ◽  
...  
Keyword(s):  
Giant Planets ◽  
High Mass ◽  
Orbital Eccentricity ◽  
Limited Sample ◽  
Hot Jupiters ◽  
Eccentric Orbits ◽  
Current Location ◽  
Short Period

Abstract We report the discovery of two short-period massive giant planets from NASA’s Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30 minute cadence full-frame images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESS’s follow-up observing program working group. We find that TOI-558 b, which transits an F-dwarf (M * = 1.349 − 0.065 + 0.064 M ⊙, R * = 1.496 − 0.040 + 0.042 R ⊙, T eff = 6466 − 93 + 95 K, age 1.79 − 0.73 + 0.91 Gyr) with an orbital period of 14.574 days, has a mass of 3.61 ± 0.15 M J, a radius of 1.086 − 0.038 + 0.041 R J, and an eccentric (e = 0.300 − 0.020 + 0.022 ) orbit. TOI-559 b transits a G dwarf (M * = 1.026 ± 0.057 M ⊙, R * = 1.233 − 0.026 + 0.028 R ⊙, T eff = 5925 − 76 + 85 K, age 6.8 − 2.0 + 2.5 Gyr) in an eccentric (e = 0.151 ± 0.011) 6.984 days orbit with a mass of 6.01 − 0.23 + 0.24 M J and a radius of 1.091 − 0.025 + 0.028 R J. Our spectroscopic follow up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive (>3 M J), adding to the population of massive giant planets identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot and warm Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies.

scholarly journals SOPHIE velocimetry of Kepler transit candidates

2019 ◽  
Vol 623 ◽  
pp. A104 ◽  
Author(s):  
G. Hébrard ◽  
A. S. Bonomo ◽  
R. F. Díaz ◽  
A. Santerne ◽  
N. C. Santos ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Orbital Period ◽  
Planetary System ◽  
Giant Planet ◽  
Eccentric Orbit ◽  
Promising Candidate ◽  
Single Star ◽  
Orbital Periods ◽  
Host Stars

Whereas thousands of transiting giant exoplanets are known today, only a few are well characterized with long orbital periods. Here we present KOI-3680b, a new planet in this category. First identified by the Kepler team as a promising candidate from the photometry of the Kepler spacecraft, we establish here its planetary nature from the radial velocity follow-up secured over 2 yr with the SOPHIE spectrograph at Observatoire de Haute-Provence, France. The combined analysis of the whole dataset allows us to fully characterize this new planetary system. KOI-3680b has an orbital period of 141.2417 ± 0.0001 days, a mass of 1.93 ± 0.20 MJup, and a radius of 0.99 ± 0.07 RJup. It exhibits a highly eccentric orbit (e = 0.50 ± 0.03) around an early G dwarf. KOI-3680b is the transiting giant planet with the longest period characterized so far around a single star; it offers opportunities to extend studies which were mainly devoted to exoplanets close to their host stars, and to compare both exoplanet populations.

scholarly journals Extrasolar planets and brown dwarfs around AF-type stars

2019 ◽  
Vol 621 ◽  
pp. A87 ◽  
Author(s):  
S. Borgniet ◽  
A.-M. Lagrange ◽  
N. Meunier ◽  
F. Galland ◽  
L. Arnold ◽  
...  
Keyword(s):  
Main Sequence ◽  
Extrasolar Planets ◽  
Giant Planet ◽  
High Amplitude ◽  
Stellar Mass ◽  
Occurrence Rate ◽  
Substellar Companions ◽  
Orbital Periods ◽  
The Impact

Context. The impact of stellar mass on the properties of giant planets is still not fully understood. Main-sequence (MS) stars more massive than the Sun remain relatively unexplored in radial velocity (RV) surveys, due to their characteristics which hinder classical RV measurements. Aims. Our aim is to characterize the close (up to ~2 au) giant planet (GP) and brown dwarf (BD) population around AF MS stars and compare this population to stars with different masses. Methods. We used the SOPHIE spectrograph located on the 1.93 m telescope at Observatoire de Haute-Provence to observe 125 northern, MS AF dwarfs. We used our dedicated SAFIR software to compute the RV and other spectroscopic observables. We characterized the detected substellar companions and computed the GP and BD occurrence rates combining the present SOPHIE survey and a similar HARPS survey. Results. We present new data on two known planetary systems around the F5-6V dwarfs HD 16232 and HD 113337. For the latter, we report an additional RV variation that might be induced by a second GP on a wider orbit. We also report the detection of 15 binaries or massive substellar companions with high-amplitude RV variations or long-term RV trends. Based on 225 targets observed with SOPHIE and/or HARPS, we constrain the BD frequency within 2–3 au around AF stars to be below 4% (1σ). For Jupiter-mass GPs within 2–3 au (periods ≤103 days), we find the occurrence rate to be 3.7−1+3% around AF stars with masses <1.5 M⊙, and to be ≤6% (1σ) around AF stars with masses >1.5 M⊙. For periods shorter than 10 days, we find the GP occurrence rate to be below 3 and 4.5% (1σ), respectively. Our results are compatible with the GP frequency reported around FGK dwarfs and are compatible with a possible increase in GP orbital periods with stellar mass as predicted by formation models.

An attempt to constrain Planet Nine’s orbit and position via resonant confinement of distant TNOs

2020 ◽  
Vol 494 (2) ◽  
pp. 2045-2052
Author(s):  
Brynna G Downey ◽  
Alessandro Morbidelli
Keyword(s):  
Numerical Simulations ◽  
Time Scale ◽  
Semimajor Axis ◽  
Giant Planets ◽  
Term Survival ◽  
Long Term Survival ◽  
3D Simulations ◽  
Orbital Periods ◽  
Strict Requirement

ABSTRACT We considered four TNOs on elongated orbits with small semimajor axis uncertainties: Sedna, 2004 VN112, 2012 VP113, and 2000 CR105. We found two sets of simultaneous near commensurabilities for these objects with a putative Planet Nine that are compatible with the current uncertainties in the objects’ orbital periods. We conducted a large number of numerical simulations of quasi-coplanar simulations (i.e. inclinations of Planet Nine and TNOs set to zero but not the giant planets) to find which values of Planet Nine’s mean anomaly and longitude of perihelion could put these objects in stable mean motion resonance (MMR) librations. We found no cases of simultaneous stable librations for multiple TNOs for more than 800 My, with most librations lasting much shorter than this time-scale. The objects 2004 VN112 and 2000 CR105 are the most unstable. Being in an MMR is not a strict requirement for long-term survival in 3D simulations, so our result cannot be used to refute Planet Nine’s existence. Nevertheless, it casts doubt and shows that theoretical attempts to constrain the position of the planet on the sky are not possible.

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