Detecting planets around early-type stars with high-resolution infrared spectroscopy

Research Project

Project/Area Number	16K13784
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Astronomy
Research Institution	Tokyo Institute of Technology
Principal Investigator	Sato Bunei 東京工業大学, 理学院, 准教授 (40397823)
Project Period (FY)	2016-04-01 – 2020-03-31
Project Status	Completed (Fiscal Year 2019)
Budget Amount *help	¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000) Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000) Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords	太陽系外惑星 / 光学赤外線天文学 / 早期型星 / 高分散分光
Outline of Final Research Achievements	We have developed a method to detect exoplanets around early-type stars, which are normally difficult to detect with conventional techniques. While there are almost no spectral lines in stellar spectra of early-type stars that are available for measurements of stellar radial velocities, this in turn would make it easier to detect planetary spectra that are embedded into observed spectra of planet-harboring stars. We performed numerical simulation to test validity of this method using mock data. We found that we can detect planetary signal around early-type stars in M-band of mid-infrared wavelength range if telluric lines can be clearly removed from observed spectra with high-resolution spectroscopic observations. This method will be useful to detect and characterize planets around early-type stars with extremely large telescopes in future.
Academic Significance and Societal Importance of the Research Achievements	本研究は、従来困難であった早期型星周りの惑星系を発見・確認するための新たな方法論の一つを提示するものであり、系外惑星研究において新たな分野を切り拓く可能性を秘めている。特に、惑星のトランジットが観測されていないくても適用できるため、従来発見できなかった惑星の発見が可能になるという点で有用である。系外惑星は社会的にも関心の高い研究分野であり、新たな知見を社会に還元できるという意義がある。