50 research outputs found

    A Double Planetary System around the Evolved Intermediate-Mass Star HD 4732

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    We report the detection of a double planetary system orbiting around the evolved intermediate-mass star HD 4732 from precise Doppler measurements at Okayama Astrophysical Observatory (OAO) and Anglo-Australian Observatory (AAO). The star is a K0 subgiant with a mass of 1.7 M_sun and solar metallicity. The planetary system is composed of two giant planets with minimum mass of msini=2.4 M_J, orbital period of 360.2 d and 2732 d, and eccentricity of 0.13 and 0.23, respectively. Based on dynamical stability analysis for the system, we set the upper limit on the mass of the planets to be about 28 M_J (i>5 deg) in the case of coplanar prograde configuration.Comment: 12 pages, 7 figures, accepted for publication in Ap

    Novel Treatment Criteria for Persistent Ductus Arteriosus in Neonates

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    BackgroundThe indications for ductus arteriosus ligation in very-low-birth-weight infants (VLBWIs) with persistent ductus arteriosus (PDA) are unclear. Increased left ventricular end-diastolic dimension (LVDd) is commonly found in patients with PDA. Here, the enlargement of LVDd in term and preterm neonates without congenital heart disease was estimated by two-dimensional echocardiography.MethodsThe value of the measured LVDd was divided by the normal LVDd as an index (LVDd ratio) to compare 30 patients who underwent PDA ligation with 30 patients treated with indomethacin and 30 patients who did not undergo radical therapy.ResultsAn LVDd ratio between 122% and 197% (mean, 142%) was considered to be an indication for the ligation procedure. The proportion of patients exceeding 130% in the LVDd ratio was 87% (26/30) in those patients who underwent ligation. Catecholamines and/or vasodilators were required in 83% patients for the treatment of low ejection fraction or hypertension after operations, suggesting that patients had been in preload and/or afterload remodeling failure during the operation. The percentage of patients with less than 115% in the LVDd ratio was 90% in the non-radical-therapy patients. The LVDd ratios of 130% and 115% were regarded as cut-off values for surgical ligation and indomethacin treatment.ConclusionThe LVDd ratio is a useful measure to determine the treatment of VLBWIs with PDA

    2-Methyl-1,2-benzisothia­zol-3(2H)-one 1,1-dioxide

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    All atoms of the title mol­ecule, C8H7NO3S, except the two oxide O atoms and two H atoms of the methyl group, lie on a crystallographic mirror plane. The crystal structure is stabilized by weak inter- and intra­molecular C—H⋯O hydrogen bonds

    A Trio of Giant Planets Orbiting Evolved Star HD 184010

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    We report the discovery of a triple-giant-planet system around an evolved star HD 184010 (HR 7421, HIP 96016). This discovery is based on observations from Okayama Planet Search Program, a precise radial velocity survey, undertaken at Okayama Astrophysical Observatory between 2004 April and 2021 June. The star is K0 type and located at beginning of the red-giant branch. It has a mass of 1.350.21+0.19M1.35_{-0.21}^{+0.19} M_{\odot}, a radius of 4.860.49+0.55R4.86_{-0.49}^{+0.55} R_{\odot}, and a surface gravity logg\log g of 3.180.07+0.083.18_{-0.07}^{+0.08}. The planetary system is composed of three giant planets in a compact configuration: The planets have minimum masses of Mbsini=0.310.04+0.03MJM_{\rm{b}}\sin i = 0.31_{-0.04}^{+0.03} M_{\rm{J}}, Mcsini=0.300.05+0.04MJM_{\rm{c}}\sin i = 0.30_{-0.05}^{+0.04} M_{\rm{J}}, and Mdsini=0.450.06+0.04MJM_{\rm{d}}\sin i = 0.45_{-0.06}^{+0.04} M_{\rm{J}}, and orbital periods of Pb=286.60.7+2.4 dP_{\rm{b}}=286.6_{-0.7}^{+2.4}\ \rm{d}, Pc=484.33.5+5.5 dP_{\rm{c}}=484.3_{-3.5}^{+5.5}\ \rm{d}, and $P_{\rm{d}}=836.4_{-8.4}^{+8.4}\ \rm{d},respectively,whicharederivedfromatripleKeplerianorbitalfittothreesetsofradialvelocitydata.Theratiooforbitalperiodsarecloseto, respectively, which are derived from a triple Keplerian orbital fit to three sets of radial velocity data. The ratio of orbital periods are close to P_{\rm{d}}:P_{\rm{c}}:P_{\rm{b}} \sim 21:12:7,whichmeanstheperiodratiosbetweenneighboringplanetsarebothlowerthan, which means the period ratios between neighboring planets are both lower than 2:1.Thedynamicalstabilityanalysisrevealsthattheplanetsshouldhavenearcircularorbits.Thesystemcouldremainstableover1Gyr,initializedfromcoplanarorbits,loweccentricities(. The dynamical stability analysis reveals that the planets should have near-circular orbits. The system could remain stable over 1 Gyr, initialized from co-planar orbits, low eccentricities (e=0.05),andplanetmassesequaltotheminimummassderivedfromthebestfitcircularorbitfitting.Besides,theplanetsarenotlikelyinmeanmotionresonance.HD184010systemisunique:itisthefirstsystemdiscoveredtohaveahighlyevolvedstar(), and planet masses equal to the minimum mass derived from the best-fit circular orbit fitting. Besides, the planets are not likely in mean motion resonance. HD 184010 system is unique: it is the first system discovered to have a highly evolved star (\log g < 3.5cgs)andmorethantwogiantplanetsallwithintermediateorbitalperiods( cgs) and more than two giant planets all with intermediate orbital periods (10^2\ \rm{d} < P < 10^3\ \rm{d}$).Comment: 20 pages, 5 figures, Published in PAS

    VHF data transmission experiments using MBC equipment conducted during the period from JARE-43 to JARE-45

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    In order to study the ability of meteor burst communications (MBC) as a new medium of data collection networks in Antarctica, we have performed a series of VHF data transmission experiments. In the experiment during the period of JARE-43 (the 43rd Japanese Antarctic Research Expedition), a remote station at Zhongshan Station sent data packets to a master station at Syowa Station using a commercial MBC system. Together with meteor burst propagations, non-meteoric propagations were frequently observed during local nighttime. We found that they worked effectively for packet transmissions and greatly increased the data throughput. Overall data throughput obtained by this experiment was 0.63bps. In JARE-44, we added another remote station at Dome Fuji Station. Since the transmitted power from the master unit was split into two directions, data throughput from Zhongshan Station was reduced to 0.36bps. That from Dome Fuji Station was only 0.13bps. For the experiment in JARE-45, we replaced the commercial MBC system with a RANDOM (RAdio Network for Data Over Meteor) system developed by the authors. The experiment is being conducted between Syowa and Zhongshan Stations. The estimated data throughput during the period from April 1st, 2004 to August 31st, 2004 was 2.9bps

    A double planetary system around the evolved intermediate-mass star HD 4732

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    We report the detection of a double planetary system orbiting around the evolved intermediate-mass star HD 4732 from precise Doppler measurements at Okayama Astrophysical Observatory and Australian Astronomical Observatory. The star is a K0 subgiant with a mass of 1.7 M⊙ and solar metallicity. The planetary system is composed of two giant planets with minimum mass of m sin i = 2.4 MJ, orbital period of 360.2 days and 2732 days, and eccentricity of 0.13 and 0.23, respectively. Based on dynamical stability analysis for the system, we set the upper limit on the mass of the planets to be about 28 MJ (i greater than 5°) in the case of coplanar prograde configuration

    A pair of giant planets around the evolved intermediate-mass star hd 47366: multiple circular orbits or a mutually retrograde configuration

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    We report the detection of a double planetary system around the evolved intermediate-mass star HD 47366 from precise radial-velocity measurements at the Okayama Astrophysical Observatory, Xinglong Station, and Australian Astronomical Observatory. The star is a K1 giant with a mass of 1.81 ± 0.13 Me, a radius of 7.30 ± 0.33 Re, and solar metallicity. The planetary system is composed of two giant planets with minimum masses of 1.75 +0.20 to -0.17 MJ and 1.86 +0.16 to -0.15 MJ, orbital periods of 363.3 +2.5 to -2.4 days and 684.7 +5.0 to -4.9 days and eccentricities of 0.089 +0.079 to -0.060 and 0.278 +0.067 to -0.094, respectively, which are derived by a double Keplerian orbital fit to the radial-velocity data. The system adds to the population of multi-giant-planet systems with relatively small orbital separations, which are preferentially found around evolved intermediate-mass stars. Dynamical stability analysis for the system revealed, however, that the best-fit orbits are unstable in the case of a prograde configuration. The system could be stable if the planets were in 2:1 mean-motion resonance, but this is less likely, considering the observed period ratio and eccentricity. A present possible scenario for the system is that both of the planets have nearly circular orbits, namely the eccentricity of the outer planet is less than ∼0.15, which is just within 1.4σ of the best-fit value, or the planets are in a mutually retrograde configuration with a mutual orbital inclination larger than 160°
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