[P-AE17] 系外惑星

[PAE17-P03] A search for auroral radio emission from β Pictoris b

*潮平 雄太¹、藤井 友香²、北 元³、木村 智樹⁴、寺田 由佳^5,6、高橋 慶太郎^1,2 (1.熊本大学、2.国立天文台、3.東北工業大学、4.東京理科大学、5.中央研究院天文及天文物理研究所、6.国立台湾大学)

キーワード：系外惑星、オーロラ電波、β Pictoris b

Magnetized exoplanets can be the source of the auroral radio emission, and observing this emission from planets potentially enables us to constrain planetary magnetic field strength. Although close-in planets have been expected to drive intense emission through the interaction with the host star wind and have been targets in many previous observations, no clear detection has been reported yet. Meanwhile, long-orbit planets could also emit strong auroral radio emissions via a mechanism similar to that of Jovian radio emission, namely magnetosphere-ionosphere coupling, if the planet has strong magnetic field, fast rotation and plasma sources.

In this work, we searched for the signal from β Pictoris b using upgrade Giant Metrewave Radio Telescope (uGMRT). Observation of this target was motivated by its large mass and high luminosity, which may lead to strong magnetic field, as well as the reported fast rotation (~8 hours) and the approximately edge-on orbital geometry. Assuming β Pictoris b has plasma sources such as satellites in the magnetosphere, it could have strong auroral radio emission. The observations were carried out for 8 hours in total in band 3 centered at 400 MHz (250-500MHz). We detected no signal and set 3σ upper limits of 0.18 mJy. We will discuss the constraints on the parameters obtained from this upper limit.