Vbvastr 001

Page 52

7.2

Òåìïåðàòóðà ÿäðà çâåçäû

7.2.1

Ýíåðãèÿ ÷åðíîãî èçëó÷åíèÿ

Ýíåðãèÿ ÷åðíîãî èçëó÷åíèÿ â ÿäðå E? (br) =

π2 kT? 15

kT? ~c

3

(7.14)

V? .

Ýíåðãèÿ ÷åðíîãî èçëó÷åíèÿ â àòìîñôåðå Z

R0

Ea (br) = 4π R?

π2 kT? 15

kT? ~c

3

R? r

16

r2 dr =

3 π2 kT? 13 15

kT? ~c

3 V? .

(7.15)

Ïîëíàÿ ýíåðãèÿ ÷åðíîãî èçëó÷åíèÿ 16 π 2 E(br) = E? (br) + Ea (br) = kT? 13 15 7.2.2

3

kT? ~c

π2 V? = 1.23 kT? 15

kT? ~c

3

V? . (7.16)

Ïîëíàÿ ýíåðãèÿ çâåçäû

 ñîîòâåòñòâèè ñ (7.3) ïîëíàÿ ýíåðãèÿ çâåçäû (7.17)

E star = −E kinetic + E(br),

òî åñòü E star = −

15 16 π 2 kT? N? + kT? 7 13 15

kT? ~c

3 V? .

(7.18)

Óñòîé÷èâîå ñîñòîÿíèå çâåçäû îïðåäåëÿåòñÿ ìèíèìóìîì åå ýíåðãèè

dE star dT?

= 0,

(7.19)

N=const,V=const

÷òî ñîîòâåòñòâóåò óñëîâèþ −

64π 2 15 N? + 7 13 · 15

kT? ~c

3 V? = 0,

(7.20)

èç êîòîðîãî ñ ó÷åòîì (4.18) îïðåäåëÿåì ðàâíîâåñíóþ òåìïåðàòóðó ÿäðà T? =

25 · 13 28π 4

1/3

~c kaB

51

Z ≈ Z · 2.13 · 107 K.

(7.21)


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