scholarly journals Using HARPS-N to characterize the long-period planets in the PH-2 and Kepler-103 systems

2019 ◽  
Vol 490 (4) ◽  
pp. 5103-5121
Author(s):  
Sophie C Dubber ◽  
Annelies Mortier ◽  
Ken Rice ◽  
Chantanelle Nava ◽  
Luca Malavolta ◽  
...  
Keyword(s):  
Light Curve ◽  
Bulk Density ◽  
High Precision ◽  
Orbital Period ◽  
Full Range ◽  
Intermediate Mass ◽  
Single Star ◽  
Long Period ◽  
Mass Estimate ◽  
The Masses

ABSTRACT We present confirmation of the planetary nature of PH-2b, as well as the first mass estimates for the two planets in the Kepler-103 system. PH-2b and Kepler-103c are both long-period and transiting, a sparsely populated category of exoplanets. We use Kepler light-curve data to estimate a radius, and then use HARPS-N radial velocities to determine the semi-amplitude of the stellar reflex motion and, hence, the planet mass. For PH-2b we recover a 3.5σ mass estimate of $M_\mathrm{ p} = 109^{+30}_{-32}$ M⊕ and a radius of Rp = 9.49 ± 0.16 R⊕. This means that PH-2b has a Saturn-like bulk density and is the only planet of this type with an orbital period P > 200 d that orbits a single star. We find that Kepler-103b has a mass of $M_{\text{p,b}} = 11.7^{+4.31}_{-4.72}$ M⊕ and Kepler-103c has a mass of $M_{\text{p,c}} = 58.5^{+11.2}_{-11.4}$ M⊕. These are 2.5σ and 5σ results, respectively. With radii of $R_{\text{p,b}} = 3.49^{+0.06}_{-0.05}$ R⊕ and $R_{\text{p,c}} = 5.45^{+0.18}_{-0.17}$ R⊕, these results suggest that Kepler-103b has a Neptune-like density, while Kepler-103c is one of the highest density planets with a period P > 100 d. By providing high-precision estimates for the masses of the long-period, intermediate-mass planets PH-2b and Kepler-103c, we increase the sample of long-period planets with known masses and radii, which will improve our understanding of the mass–radius relation across the full range of exoplanet masses and radii.

scholarly journals Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit

2020 ◽  
Vol 494 (1) ◽  
pp. 750-763 ◽  
Author(s):  
N L Eisner ◽  
O Barragán ◽  
S Aigrain ◽  
C Lintott ◽  
G Miller ◽  
...  
Keyword(s):  
Light Curve ◽  
Parameter Space ◽  
Orbital Period ◽  
Semimajor Axis ◽  
First Year ◽  
Speckle Imaging ◽  
Long Period ◽  
Upper Limit ◽  
Detailed Modelling

ABSTRACT We report on the discovery and validation of TOI 813 b (TIC 55525572 b), a transiting exoplanet identified by citizen scientists in data from NASA’s Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant ($R_\star =1.94\, R_\odot$, $M_\star =1.32\, M_\odot$). It was observed almost continuously by TESS during its first year of operations, during which time four individual transit events were detected. The candidate passed all the standard light curve-based vetting checks, and ground-based follow-up spectroscopy and speckle imaging enabled us to place an upper limit of $2\, M_{\rm Jup}$ (99 per cent confidence) on the mass of the companion, and to statistically validate its planetary nature. Detailed modelling of the transits yields a period of $83.8911 _{ - 0.0031 } ^ { + 0.0027 }$ d, a planet radius of 6.71 ± 0.38 R⊕ and a semimajor axis of $0.423 _{ - 0.037 } ^ { + 0.031 }$ AU. The planet’s orbital period combined with the evolved nature of the host star places this object in a relatively underexplored region of parameter space. We estimate that TOI 813 b induces a reflex motion in its host star with a semi-amplitude of ∼6 m s−1, making this a promising system to measure the mass of a relatively long-period transiting planet.

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.

The Eclipsing Binary WX Eridani

1979 ◽  
Vol 46 ◽  
pp. 385
Author(s):  
M.B.K. Sarma ◽  
K.D. Abhankar
Keyword(s):  
Light Curve ◽  
Spectral Type ◽  
Orbital Period ◽  
Primary Component ◽  
Light Curves ◽  
Absorption Feature ◽  
Primary Star ◽  
Eclipsing Binary ◽  
The Times ◽  
Phase Angles

AbstractThe Algol-type eclipsing binary WX Eridani was observed on 21 nights on the 48-inch telescope of the Japal-Rangapur Observatory during 1973-75 in B and V colours. An improved period of P = 0.82327038 days was obtained from the analysis of the times of five primary minima. An absorption feature between phase angles 50-80, 100-130, 230-260 and 280-310 was present in the light curves. The analysis of the light curves indicated the eclipses to be grazing with primary to be transit and secondary, an occultation. Elements derived from the solution of the light curve using Russel-Merrill method are given. From comparison of the fractional radii with Roche lobes, it is concluded that none of the components have filled their respective lobes but the primary star seems to be evolving. The spectral type of the primary component was estimated to be F3 and is found to be pulsating with two periods equal to one-fifth and one-sixth of the orbital period.

RSCVn Stars in the Southern Hemisphere

1979 ◽  
Vol 46 ◽  
pp. 371-384 ◽  
Author(s):  
J.B. Hearnshaw
Keyword(s):  
Light Curve ◽  
Southern Hemisphere ◽  
Orbital Period ◽  
Binary Stars ◽  
Small Amplitude ◽  
Light Variation ◽  
Orbital Phase

RSCVn stars are fully detached binary stars which show intrinsic small amplitude (up to 0.3 amplitude peak-to-peak) light variations, as well as, in most of the known cases, eclipses. The spectra are F to G, IV to V for the hotter component and usually KOIV for the cooler. They are also characterised by abnormally strong H and K emission from the cooler star, or, occasionally, from both components. The orbital and light curve periods are in the range 1 day to 2 weeks. An interesting feature is the migration of the light variations to earlier orbital phase, as the light variation period is shorter than the orbital period by a few parts in 10+4to a few parts in 10+3.

scholarly journals The central dynamics of M3, M13, and M92: stringent limits on the masses of intermediate-mass black holes

2014 ◽  
Vol 566 ◽  
pp. A58 ◽  
Author(s):  
S. Kamann ◽  
L. Wisotzki ◽  
M. M. Roth ◽  
J. Gerssen ◽  
T.-O. Husser ◽  
...  
Keyword(s):  
Black Holes ◽  
Intermediate Mass ◽  
The Masses ◽  
Intermediate Mass Black Holes

scholarly journals A Model Study of Building Seismic Damage Information Extraction and Analysis on Ground-Based LiDAR Data

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Fan Yang ◽  
Xintao Wen ◽  
Xiaoshan Wang ◽  
Xiaoli Li ◽  
Zhiqiang Li
Keyword(s):  
High Precision ◽  
Laser Scanning ◽  
Full Range ◽  
Scientific Basis ◽  
Building Damage ◽  
Vector Model ◽  
Lidar Data ◽  
Emergency Relief ◽  
Cloud Data ◽  
Ground Based Lidar

Earthquake disasters can have a serious impact on people’s lives and property, with damage to buildings being one of the main causes of death and injury. A rapid assessment of the extent of building damage is essential for emergency response management, rescue operations, and reconstruction. Terrestrial laser scanning technology can obtain high precision light detection and ranging (LiDAR) point cloud data of the target. The technology is widely used in various fields; however, the quantitative analysis of building seismic information is the focus and difficulty of ground-based LiDAR data analysis processing. This paper takes full advantage of the high-precision characteristics of ground-based LiDAR data. A triangular network vector model (TIN-shaped model) was created in conjunction with the alpha shapes algorithm, solving the problem of small, nonvisually identifiable postearthquake building damage feature extraction bias. The model measures the length, width, and depth of building cracks, extracts the amount of wall tilt deformation, and labels the deformation zone. The creation of this model can provide scientific basis and technical support for postearthquake emergency relief, assessment of damage to buildings, extraction of deformation characteristics of other structures (bridges, tunnels, dams, etc.), and seismic reinforcement of buildings. The research data in this paper were collected by the author’s research team in the first time after the 2013 Lushan earthquake and is one of the few sets of foundation of LiDAR data covering the full range of postearthquake building types in the region, with the data information mainly including different damage levels of different structural types of buildings. The modeling analysis of this data provides a scientific basis for establishing the earthquake damage matrix of buildings in the region.

scholarly journals The Initial Period of Activity of the Central Council of Ukraine: Since March 3 (16) till the National Congress in April 1917

2021 ◽  
pp. 110-123
Author(s):  
Oleksandr Kucheruk
Keyword(s):  
Initial Period ◽  
Full Range ◽  
Historical Context ◽  
Initial Stage ◽  
Central Council ◽  
Public Consciousness ◽  
National Life ◽  
National Congress ◽  
The Russian Empire ◽  
The Masses

Among many issues related to the phenomenon of the Ukrainian Revolution of 1917–1921, the specifics of the development of the earliest stage of its history attracts special attention of the researchers. It is no accident, because during this period the Ukrainian national movement in the Russian Empire, which was in fact totally banned with the outbreak of the First World War, proved its strength and its ability to become a real factor in mobilizing the masses. The logic of historical events initiated almost immediately by the appearance in early March 1917 in Kyiv of the organizational center of Ukrainians led to a revolutionary transformation of public consciousness in terms of moderate demands made in pre-revolutionary times by a relatively small group of public figures, as well as to a strong assertion of the sovereign will of the Ukrainian people, who had irreversibly embarked on the path of state formation. The demands mainly concerned schooling, basic opportunities for development of national culture and extremely limited forms of local self-government.In view of this, the article considers both the historical context, circumstances and conditions of the establishment of the Central Council of Ukraine, and the peculiarities of positioning the representatives of various political currents during the least documented period: from the end of February 1917 to the All-Ukrainian National Congress (April 6-8, 1917). Based on the analysis of the recollections of participants and witnesses of the process, periodicals and official publications of the Central Council of Ukraine, the names of the Ukrainian figures who were its founding members, were clarified. It was emphasized that, despite the dissatisfaction of the older Ukrainian activists associated with the Society of Ukrainian Progressives, this revolutionary parliament began to form as a broad union of groups, parties and organizations representing the full range of Ukrainian political forces at the time. Particular attention is paid to the fact that at the initial stage of formation of the Central Council of Ukraine the problem of consolidation has become one of the most pressing on the agenda of national life.

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 The O-type spectroscopic binary system HD 93206

1979 ◽  
Vol 83 ◽  
pp. 277-280 ◽  
Author(s):  
Nancy D. Morrison ◽  
Peter S. Conti
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Mass Loss ◽  
Massive Stars ◽  
Radial Velocities ◽  
Mass Determination ◽  
Spectroscopic Binary ◽  
The Masses

The star HD 93206 (=QZ Carinae) is a double-lined (Conti et al. 1977), eclipsing (Moffat and Seggewiss 1972) binary with a period of 6 d. Walborn (1973) classified it 09.7Ib:(n). Since the star is probably a member of the cluster Collander 228 (which is near η Carinae), its distance can be assumed to be 2600 pc. In principle, one can determine the masses of the components of HD 93206 from observations of the radial velocities and the light curve, and a spectroscopic orbit is the object of this investigation. A mass determination for an evolved star such as this one is especially important for checking recently computed evolutionary tracks with mass loss for massive stars (de Loore et al. 1977, Chiosi et al. 1978, Dearborn et al. 1978).

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