Exercice 1 : Détection de naines brunes. Exercice 2 : Influence de la

f T
f=σT 4
R F = 4πR2σT 4Fb/F?=R2
bT4 b
R2
?T4 ?
Fb/F?= 6.110−5
Θ = 1.22λ/D Θλ D
s= 1.22dλ/D s = 1.5
m=−2.5 log{10−0.4m1+ 10−0.4m2}
B−V=−2.5 log{10−0.4B1+ 10−0.4B2}+ 2.5 log{10−0.4V1+ 10−0.4V2}=−2.5 log{10−0.4B1+10−0.4B2
10−0.4V1+10−0.4V2}
V=−0.05 B−V= 0.00
V= 0.41 B−V= 0.03
∼1012M
∼1011M
∼109−1010M
∼108−109M
Sν∼
Sν∝ν−0.8
νG< ν0∆v/c = ∆ν/ν0
∆v/c = ∆λ/λ0
νG= 1.4156707 ∆v= 634
Θ = 1.22λ/D = 8.40ΩA=πΘ2/4 ln 2 Aeff =λ2/ΩA= 5929m2
1
2SAeff =kT S = 2.3
V=−2.5 log F+c V −V0=−2.5 log F
F0V0= 0
F
F0=N N0
N=N010−0.4V= 1000 ×1000 ×1×π4002×10−0.4×20 = 5026 √N= 70