M 型矮星的閃焰活動以及極端太空天氣對於 TRAPPIST-1 行星系統的影響;M-Dwarf Flare Activity and Extreme Space Weather Effects on TRAPPIST-1 System

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/89192

Title:	M 型矮星的閃焰活動以及極端太空天氣對於 TRAPPIST-1 行星系統的影響;M-Dwarf Flare Activity and Extreme Space Weather Effects on TRAPPIST-1 System
Authors:	翁郁翔;Weng, Yu-Hsiang
Contributors:	天文研究所
Keywords:	紅矮星;系外行星;閃焰;適居性;Red dwarf;Exoplanets;Flares;Habitability
Date:	2022-08-31
Issue Date:	2022-10-04 11:00:48 (UTC+8)
Publisher:	國立中央大學
Abstract:	經由TESS任務提供的99顆M型矮星光變曲線，我們可以得知恆星的活躍程度。其中的33顆恆星表現出強烈的恆星磁活動。這些總計322個閃焰的能量大致上介於10^31~10^35 爾格。然後我們利用這些資料建造出閃焰能量頻率分佈圖(flare frequency distribution) 並且分析了他們自轉周期跟閃焰頻率的關係。這些閃焰能量頻率分佈圖可以用來評估系外行星的適居性。經過測試，TRAPPIST-1 這顆光譜型為M8紅矮星的日冕物質拋射(coronal mass ejection) 會以4.96%的機率打到他的附屬行星。另外，經由數值模擬我們知道在有磁場為75高斯的恆星上，能量小於6*10^32 爾格的閃焰會生成日冕雨並回到恆星表面，導致無法成功製造日冕物質拋射(Alvarado-Gómezet al., 2018)。 TRAPPIST-1 經由日冕物質拋射的質量損失在100億年間總計來到10^29 公克，把金星的條件應用在它的這些系外行星上(無磁場且大氣由二氧化碳構成)，這些日冕物質拋射會造成系外行星大氣質量在100億年間總損失介於10^19 ~ 10^23 公克。系外行星大氣經由穩定吹拂的恆星風影響，則會在100億年間損失總質量介於10^21 ~ 10^25 公克。利用行星大氣質量損失可以推斷系外行星的適居性。 ;The TESS mission has obtained a light curve of 99 M dwarfs that we can have a survey to figure out their activity. It was found that 33 stars in our sam- ple exhibited magnetic activity. In total, 322 flares are identified, and the flare energies are generally in the range of 10^31 ∼ 10^35 ergs. We construct these M- type star datasets’ flare frequency distribution (FFD) and analyze the relation be- tween rotation period and flare frequency. FFDs can tell us the star activity to as- sess the habitability of the exoplanets. We tested an M8 dwarf star TRAPPIST-1 and found that the probability of a flare-associated coronal mass ejection (CME) hit on the exoplanet is about 4.96%. Due to numerical simulation, flare energy lower than 6 ∗ 10^32 erg will form a coronal rain back to the star and can not be a CME successfully in a 75G magnetic field star (Alvarado-Gómez et al., 2018). TRAPPIST-1 total mass loss by CME can up to 10^29 g in 10 Gyr, so cause its ex- oplanets loss their atmosphere in the range 10^19 ∼ 10^23 in 10 Gyr totally which was applied Venus-like case (no magnetic field and only CO2 atmosphere) on it. Also, we found the total atmospheric mass loss by the steady stellar wind was in the range 10^21 ∼ 10^25 in 10 Gyr. These atmospheric m
Appears in Collections:	[Graduate Institute of Astronomy] Electronic Thesis & Dissertation

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