We report the discovery of a substellar companion around the intermediate- mass giant HD 175679. Precise radial velocity data of the star from the Xinglong Station and the Okayama Astrophysical Observatory revealed a ...We report the discovery of a substellar companion around the intermediate- mass giant HD 175679. Precise radial velocity data of the star from the Xinglong Station and the Okayama Astrophysical Observatory revealed a Keplerian velocity variation with an orbital period of 1366.8±5.7 d, a semiamplitude of 380.2±3.2 m s-1 and an eccentricity of 0.378± 0.008. Adopting a stellar mass of 2.7± 0.3 M, we obtain that the minimum mass of the HD 175679 b is 37.3± 2.8 M and the semimajor axis is 3.36±0.12 AU. This discovery is the second brown dwarf companion candidate from a joint planet-search program between China and Japan.展开更多
This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are al...This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are also summarized.Multiple assessment and navigation teams worked closely to provide reliable navigation solutions with a short solution delivery cycle.Although the uncertainty of the Ryugu’s ephemeris was considerable before Hayabusa2’s arrival,a combination of radiometric-optical hybrid navigation and a stochastic-constrained optimum guidance method was able to achieve an accuracy of less than 100 m and 1 cm/s,and the arrival was precisely timed.展开更多
This paper describes an extendable graphical framework,aflak,which provides a visualization and provenance management environment for the analysis of multi-spectral astronomical datasets.Via its node editor interface,...This paper describes an extendable graphical framework,aflak,which provides a visualization and provenance management environment for the analysis of multi-spectral astronomical datasets.Via its node editor interface,aflak allows the astronomer to compose transforms on input datasets queryable from public astronomical data repositories,then to export the results of the analysis as Flexible Image Transport System(FITS)files,in a manner such that the full provenance of the output data be preserved and reviewable,and that the exported file be usable by other common astronomical analysis software.FITS is the standard of data interchange in astronomy.By embedding aflak’s provenance data into FITS files,we both achieve interoperability with existing software and full reproducibility of the process by which astronomers make discoveries.展开更多
The discovery of a planetary companion to the intermediate-mass late-type giant star HD173416 from precise Doppler surveys of G and K giants at Xinglong station and Okayama Astrophysical Observatory （OAO） is present...The discovery of a planetary companion to the intermediate-mass late-type giant star HD173416 from precise Doppler surveys of G and K giants at Xinglong station and Okayama Astrophysical Observatory （OAO） is presented in this letter. The planet has a minimum mass of 2.7 MJ, an eccentricity of 0.21, a semimajor axis of 1.16 AU and an orbital period of 324 days.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 10821061 and 10803010)the Japan Society for the Promotion of Science under grant 08032011-000184 in the framework of the Joint Research Project between China and Japan
文摘We report the discovery of a substellar companion around the intermediate- mass giant HD 175679. Precise radial velocity data of the star from the Xinglong Station and the Okayama Astrophysical Observatory revealed a Keplerian velocity variation with an orbital period of 1366.8±5.7 d, a semiamplitude of 380.2±3.2 m s-1 and an eccentricity of 0.378± 0.008. Adopting a stellar mass of 2.7± 0.3 M, we obtain that the minimum mass of the HD 175679 b is 37.3± 2.8 M and the semimajor axis is 3.36±0.12 AU. This discovery is the second brown dwarf companion candidate from a joint planet-search program between China and Japan.
基金JSPS KAKENHI Grant No.18H01628 also supported this work.
文摘This paper describes the guidance and navigation technique used by Hayabusa2 for the asteroid rendezvous operation to reach Ryugu.The operation results,including the achieved guidance and navigation performance,are also summarized.Multiple assessment and navigation teams worked closely to provide reliable navigation solutions with a short solution delivery cycle.Although the uncertainty of the Ryugu’s ephemeris was considerable before Hayabusa2’s arrival,a combination of radiometric-optical hybrid navigation and a stochastic-constrained optimum guidance method was able to achieve an accuracy of less than 100 m and 1 cm/s,and the arrival was precisely timed.
基金JSPS KAKENHI(Japan)Grant Numbers 17K00173 and 17H00737.
文摘This paper describes an extendable graphical framework,aflak,which provides a visualization and provenance management environment for the analysis of multi-spectral astronomical datasets.Via its node editor interface,aflak allows the astronomer to compose transforms on input datasets queryable from public astronomical data repositories,then to export the results of the analysis as Flexible Image Transport System(FITS)files,in a manner such that the full provenance of the output data be preserved and reviewable,and that the exported file be usable by other common astronomical analysis software.FITS is the standard of data interchange in astronomy.By embedding aflak’s provenance data into FITS files,we both achieve interoperability with existing software and full reproducibility of the process by which astronomers make discoveries.
基金funded by the NSFC under grants 10803010 and 10521001Grants-in-Aid for Scientific Research (B) No.17340056 (H.A.)the Joint program on Search for Extra-solar planets between China and Japan (2008–2010) from the Japan Society for the Promotion of Science.
文摘The discovery of a planetary companion to the intermediate-mass late-type giant star HD173416 from precise Doppler surveys of G and K giants at Xinglong station and Okayama Astrophysical Observatory （OAO） is presented in this letter. The planet has a minimum mass of 2.7 MJ, an eccentricity of 0.21, a semimajor axis of 1.16 AU and an orbital period of 324 days.
