scholarly journals HD 219666 b: a hot-Neptune from TESS Sector 1

2019 ◽  
Vol 623 ◽  
pp. A165 ◽  
Author(s):  
M. Esposito ◽  
D. J. Armstrong ◽  
D. Gandolfi ◽  
V. Adibekyan ◽  
M. Fridlund ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Thermal Structure ◽  
Formation Mechanisms ◽  
Mass Determination ◽  
Velocity Measurements ◽  
Fundamental Parameters ◽  
Refractory Elements ◽  
Rare Class ◽  
In Transit

We report on the confirmation and mass determination of a transiting planet orbiting the old and inactive G7 dwarf star HD 219666 (M⋆ = 0.92 ± 0.03 M⊙, R⋆ = 1.03 ± 0.03 R⊙, τ⋆ = 10 ± 2 Gyr). With a mass of Mb = 16.6 ± 1.3 M⊕, a radius of Rb = 4.71 ± 0.17 R⊕, and an orbital period of Porb ≃ 6 days, HD 219666 b is a new member of a rare class of exoplanets: the hot-Neptunes. The Transiting Exoplanet Survey Satellite (TESS) observed HD 219666 (also known as TOI-118) in its Sector 1 and the light curve shows four transit-like events, equally spaced in time. We confirmed the planetary nature of the candidate by gathering precise radial-velocity measurements with the High Accuracy Radial velocity Planet Searcher (HARPS) at ESO 3.6 m. We used the co-added HARPS spectrum to derive the host star fundamental parameters (Teff = 5527 ± 65 K, log g⋆ = 4.40 ± 0.11 (cgs), [Fe/H]= 0.04 ± 0.04 dex, log R′HK = −5.07 ± 0.03), as well as the abundances of many volatile and refractory elements. The host star brightness (V = 9.9) makes it suitable for further characterisation by means of in-transit spectroscopy. The determination of the planet orbital obliquity, along with the atmosphericmetal-to-hydrogen content and thermal structure could provide us with important clues on the formation mechanisms of this class of objects.

scholarly journals Mass determination of the 1:3:5 near-resonant planets transiting GJ 9827 (K2-135)

2018 ◽  
Vol 618 ◽  
pp. A116 ◽  
Author(s):  
J. Prieto-Arranz ◽  
E. Palle ◽  
D. Gandolfi ◽  
O. Barragán ◽  
E. W. Guenther ◽  
...  
Keyword(s):  
Planetary System ◽  
Initial Conditions ◽  
Dynamical Evolution ◽  
Space Mission ◽  
Mass Determination ◽  
Velocity Measurements ◽  
Orbital Periods ◽  
The Masses ◽  
Better Than

Context. Multiplanet systems are excellent laboratories to test planet formation models as all planets are formed under the same initial conditions. In this context, systems transiting bright stars can play a key role, since planetary masses, radii, and bulk densities can be measured. Aims. GJ 9827 (K2-135) has recently been found to host a tightly packed system consisting of three transiting small planets whose orbital periods of 1.2, 3.6, and 6.2 days are near the 1:3:5 ratio. GJ 9827 hosts the nearest planetary system (~30 pc) detected by NASA’s Kepler or K2 space mission. Its brightness (V = 10.35 mag) makes the star an ideal target for detailed studies of the properties of its planets. Methods. Combining the K2 photometry with high-precision radial-velocity measurements gathered with the FIES, HARPS, and HARPS-N spectrographs we revised the system parameters and derive the masses of the three planets. Results. We find that GJ 9827 b has a mass of Mb = 3.69−0.46+0.48 M⊕ and a radius of Rb = 1.58−0.13+0.14 R⊕, yielding a mean density of ρb = 5.11−1.27+1.74 g cm−3. GJ 9827 c has a mass of Mc = 1.45−0.57+0.58 M⊕, radius of Rc = 1.24−0.11+0.11 R⊕, and a mean density of ρc = 4.13−1.77+2.31 g cm−3. For GJ 9827 d, we derive Md = 1.45−0.57+0.58 M⊕, Rd = 1.24−0.11+0.11 R⊕, and ρd = 1.51−0.53+0.71 g cm−3. Conclusions. GJ 9827 is one of the few known transiting planetary systems for which the masses of all planets have been determined with a precision better than 30%. This system is particularly interesting because all three planets are close to the limit between super-Earths and sub-Neptunes. The planetary bulk compositions are compatible with a scenario where all three planets formed with similar core and atmosphere compositions, and we speculate that while GJ 9827 b and GJ 9827 c lost their atmospheric envelopes, GJ 9827 d maintained its primordial atmosphere, owing to the much lower stellarirradiation. This makes GJ 9827 one of the very few systems where the dynamical evolution and the atmosphericescape can be studied in detail for all planets, helping us to understand how compact systems form and evolve.

scholarly journals Radial velocity measurements and orbit determination of eight single-lined spectroscopic binary systems

2017 ◽  
Vol 338 (6) ◽  
pp. 671-679 ◽  
Author(s):  
R. Bischoff ◽  
M. Mugrauer ◽  
T. Zehe ◽  
D. Wöckel ◽  
A. Pannicke ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Orbit Determination ◽  
Binary Systems ◽  
Velocity Measurements ◽  
Spectroscopic Binary

scholarly journals Asteroseismology of exoplanet host stars

2015 ◽  
Vol 11 (A29B) ◽  
pp. 620-627
Author(s):  
Daniel Huber
Keyword(s):  
Radial Velocity ◽  
Planetary Systems ◽  
Precise Determination ◽  
Spin Orbit ◽  
Velocity Measurements ◽  
Fundamental Properties ◽  
Future Space ◽  
Host Stars

AbstractAsteroseismology is among the most powerful observational tools to determine fundamental properties of stars. Space-based photometry has recently enabled the systematic detection of oscillations in exoplanet host stars, allowing a combination of asteroseismology with transit and radial-velocity measurements to characterize planetary systems. In this contribution I will review the key synergies between asteroseismology and exoplanet science such as the precise determination of radii and ages of exoplanet host stars, as well as applications of asteroseismology to measure spin-orbit inclinations in multiplanet systems and orbital eccentricities of small planets. Finally I will give a brief outlook on asteroseismic studies of exoplanet hosts with current and future space-based missions such as K2 and TESS.

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.

Sorption of Se (IV) from aqueous solutions with subsequent determination by X-ray fluorescence analysis

2020 ◽  
Vol 86 (10) ◽  
pp. 5-9
Author(s):  
D. G. Filatova ◽  
A. A. Arkhipenko ◽  
M. A. Statkus ◽  
V. V. Es’kina ◽  
V. B. Baranovskaya ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Fluorescence Analysis ◽  
Standard Samples ◽  
Phase Contact Time ◽  
Sorbent Phase ◽  
X Ray ◽  
Fundamental Parameters ◽  
Inductively Coupled ◽  
Subsequent Determination

An approach to sorptive separation of Se (IV) from solutions on a novel S,N-containing sorbent with subsequent determination of the analyte in the sorbent phase by micro-x-ray fluorescence method is presented. The sorbent copolymethylenesulfide-N-alkyl-methylenamine (CMA) was synthesized using «snake in the cage» procedure and proven to be stable in acid solutions. Conditions for quantitative extraction of Se (IV) were determined: sorption in 5 M HCl or 0.05 M HNO3 solutions when heated to 60°C, phase contact time being 1 h. The residual selenium content in the solution was determined by inductively coupled plasma mass spectrometry (ICP-MS) using 82Se isotope. The absence of selenium losses is proved and the mechanism of sorption interaction under specified conditions is proposed. The method of micro-x-ray fluorescence analysis (micro-RFA) with mapping revealed a uniform distribution of selenium on the sorbent surface. The possibility of determining selenium in the sorbent phase by micro-RFA is shown. When comparing the obtained results with the results of calculations by the method of fundamental parameters, it is shown the necessity of using standard samples of sorbates to obtain correct results of RFA determination of selenium in the sorbent phase.

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

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