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

2019 Fiscal Year Final Research Report

• 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
• 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.

Free Research Field

太陽系外惑星

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。