輔仁大學 太空物理 ( space physics )
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第一章 太陽 Chapter 1 The Sun. 輔仁大學 太空物理 ( Space Physics ). 大綱. 第 1.1 節 結構與能量 內部構造與能量傳播 第 1.2 節 太陽輻射 太陽光與太陽風 太陽風暴. 太空是什麼. Bow Shock. 1977 年. Termination Shock. Heliopause. Voysger 1 & 2 http://voyager.jpl.nasa.gov/. Heliosphere. 大氣 — 地球表面至地表 80 公里 太空 — 地球表面 50 公里到太陽系 ( 太陽風終極震波 ) - PowerPoint PPT PresentationTRANSCRIPT
第一章 太陽Chapter 1 The Sun
大綱 第 1.1 節 結構與能量
內部構造與能量傳播
第 1.2 節 太陽輻射太陽光與太陽風太陽風暴
太空是什麼
1977 年
Termination Shock
Heliopause
Heliosphere
Bow Shock
Voysger 1 & 2 http://voyager.jpl.nasa.gov/
大氣—地球表面至地表 80公里 太空—地球表面 50公里到太陽系 ( 太陽風終極震
波 )
天文—太陽、恆星、星系以至銀河科學—數學、生物、物理、化學與自然科學科技—電機、機械、土木…等工業技術
太空環境
太空科學
太空旅行 太空科技
更新:航海家 1,2 已接近日磁層頂
太陽的基本資料 年齡:快 50 億歲了 體重: 3.3×105個地球重
大小: 100 個地球半徑
密度: 1.4 g/cm3
重力: 2.7 ×102 m/s2
自轉週期:平均為 27 天
•地球重: 5.97×1027Kg
•地球半徑: 6400 Km
核 心 : 能量的來源 ( 核融合 )0.3R⊙, 1.5×107K
輻射層 : 先吸收再以輻射傳遞0.5R ⊙ , 5.0×105K
對流層 : 利用對流方式傳遞0.2R ⊙ , 6.6×105K
光球層 : 肉眼所看到的部份0.001R ⊙ , 5750K
彩球層 : 最薄的一層10000KM , 4500-500000K
日 冕 : 相當於太陽的大氣層>R ⊙ ,1.5×106K
The source of the Sun’s energy is nuclear fusionProton-proton cycle, four protons merges to one α-particle, the mass difference between the four protons and the α-particle corresponds to an energy of 4.3*10-12J or 26.2 MeV.
The first step: Two protons merge to a deuteron, emitting a positron and a neutrino.
The second step: A proton collides and merges with the deuteron, forming a 3He-nuclei under emission of a γ-quant.
The third step:Two 3He-nuclei collide, they merge to an α-particle, emitting two protons and a γ-quant .
The time scale of the proton-proton cycle basically is by the first step, half of the hydrogen initially present is converted into deuteron within 1010 year.
Although a photon travels with the speed of light, it needs about 100000 years to diffuse from the Sun’s core to its surface.
Wiki
不同波段下的太陽
EIT195 EIT284 EIT3041.5 million 2 million 80,000
MDI EIT1716000 1million
The Sun’s composition:
hydrogen 92% in terms of particle number or 72% in terms of masshelium 8%oxygen 0.06%carbon 0.03%the rest<0.01%.
The Sun radiates as a black body at about 6000 K.
The flux of visible solar energy varies very little and, however, the emissions at shorter wavelengths, the EUV and X-ray, vary by orders of magnitude depending on sunspot number and solar activity.
Differential rotation
Sunspot characteristics:
(i) Low temperature: 3900°K(ii) Intense magnetic field: 200gauss(iii) Pair (iv) Cycle~11.25 years
Wolf Sunspot number (Solar activity index, SSN,R)
Wolf number: R=k(10*g+f)f: number of individual spot g: number of groupk: comparison constant ~1 Solar min R~0 Solar max R~200
R12: 將 12 個月所觀測到的 R 值 ( 太陽黑子數 ) 相加起來除以 12R12=(0.5R-6 +R-5 +R-4 +R-3 +R-2 +R-1 +R0+R1+R2+R3+R4+R5 +0.5R6)/12
The 1st cycle: 1755~1766Now: 24th cycle, 2008.01.04 ~The Maunder Minimum: 1645~1715
不同波段的太陽黑子
近距離觀測太陽黑子
太陽的自轉—差動式自轉
太陽光譜
The solar windThe solar wind is a continuous flow of charged particle.Slow solar wind 250-400 km/s, 8ions/cm3 at 1AU, Streamer belt Strongly overexpending flux tubes.Fast solar wind 400-800 km/s, 3ions/cm3 at 1AU, Coronal hole
太陽活動強度不同之差異
tanθ=rω/Vsw
Solar index, F10.7: 以太陽表面所輻射出來之波長為 10.7cm(2800MHz) 的電磁波強度作為太陽活動強弱的參考。下圖為 F10.7 與太陽黑子數的比較。
The active Sun
Flare A flare is a burst of “light” (easily observed at red Hα
6563A) occurring in the chromosphere near a sunspot. Life time 3 min up to 2 hr.
Hα-flares are ranked in the size (importance, 1-4) and brilliance (f, n, b).
X-ray flares are classified by power flux level of 1-8A (C, M, X).
Radio burst Radio bursts are generally associated with flares
and originate from all levels of the solar atmosphere.
Class Peak (W/m2)between 1 and 8 Angstroms
B I < 10-6 C 10-6 < = I < 10-5 M 10-5 < = I < 10-4 X I > = 10-4
•X-RAY FLARE的強度區分如下表所示:
太陽黑子爆炸
太陽閃焰
日冕物質拋射
日冕物質拋射
太陽閃焰與日冕物質拋射
Exclusive views of Comet 96P/Machholz swinging past the Sun
Comet Hyakutake