Embed Size (px)
Citation preview
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ast
rono
my
210
Sect
ion
1–M
WF
150
0-15
5013
4 A
stro
nom
y B
uild
ing
Thi
s C
lass
(L
ectu
re 1
3):
The
rmal
Rad
iatio
n
Nex
t Cla
ss:
Hou
r E
xam
#1
Mus
ic: T
he S
pace
Rac
e is
Ove
r –
Bill
y B
ragg
Exa
m #
1 on
Fri
day!
Thu
rsda
y R
evie
w S
essi
on
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Mid
term
#1
•1
hour
exa
m in
this
cla
ssro
om.
•It
will
cov
er m
ater
ial u
p to
, but
not
incl
udin
g,
Bla
ckbo
dy e
mis
sion
•W
ill c
onsi
st o
f a
few
sho
rt-a
nsw
ers,
1-2
sho
rt
essa
y, a
nd a
few
pro
blem
s +
ext
ra c
redi
t.
•Y
ou c
an b
ring
a n
orm
al-s
ized
she
et o
f pa
per
with
no
tes
on b
oth
side
s.
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Out
line
•D
oppl
er E
ffec
t
•T
eles
cope
s
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Dop
pler
Eff
ect
Tho
se o
f yo
u us
e to
rac
ing
even
ts li
ke th
e In
dy 5
00, o
r th
e so
und
of a
pol
ice
sire
n, a
re u
se to
the
Dop
pler
eff
ect.
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Dop
pler
Shi
ft
•T
he a
mou
nt o
f sh
ift i
n w
avel
engt
h de
pend
s on
the
rela
tive
velo
city
of
the
sour
ce a
nd th
e ob
serv
er
•B
y m
easu
ring
the
Dop
pler
shi
ft o
f th
e lig
ht w
e ob
serv
e, w
e ca
n st
udy
the
mot
ions
of
the
plan
ets
and
star
s•
The
Dop
pler
eff
ect i
s al
so u
sed
by m
oder
n st
orm
-tr
acki
ng r
adar
×=
−c
v sour
ceso
urce
sour
ceob
sλ
λλ
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
The
Dop
pler
Eff
ect
Sour
ce s
tand
ing
still
Sour
ce m
ovin
g to
rig
ht
The
eff
ect a
rise
s fr
om th
e re
lativ
e m
otio
n of
the
obse
rver
and
the
sour
ce o
f lig
ht, s
ound
, etc
. T
he w
aves
get
squ
ashe
d in
the
dire
ctio
n of
mot
ion
and
stre
tche
d in
the
oppo
site
dir
ectio
n.
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
We
need
tele
scop
es to
obs
erve
St
arlig
ht
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
58
Tel
esco
pes
& A
stro
nom
y
•T
he s
ingl
e m
ost i
mpo
rtan
t too
l to
astr
onom
ers
is th
e te
lesc
ope
–T
hey
colle
ct m
ore
light
than
the
eye
–A
llow
us
to s
ee h
eave
nly
obje
cts
mor
e cl
earl
y an
d to
gre
ater
dis
tanc
es
•A
stro
nom
ers
have
bee
n us
ing
tele
scop
es f
or
abou
t 400
yea
rs to
ex
plor
e th
e U
nive
rse
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
The
Ele
ctro
mag
netic
Spe
ctru
m
•E
lect
rom
agne
tic
wav
es c
an h
ave
wav
elen
gths
outs
ide
of
visi
ble
rang
e
•A
stro
nom
ical
obj
ects
us
ually
em
it lig
ht a
t m
any
wav
elen
gths
•N
eed
tele
scop
es w
hich
w
ork
at a
ll w
avel
engt
hs
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
510
Fun
ctio
ns o
f a
Tel
esco
pe•
Tel
esco
pe f
unct
ions
–C
olle
ct li
ght o
ver
a la
rge
area
–R
esol
ve im
age
onto
an
eyep
iece
or
a sc
ient
ific
inst
rum
ent
•E
xtra
ct m
axim
um p
ossi
ble
info
rmat
ion
–Fo
rm im
age
or ta
ke s
pect
rum
•C
an d
o th
is w
ith e
ither
lens
es
(ref
ract
ing)
or
mir
rors
(re
flec
ting)
•T
hree
pri
oriti
es (
in o
rder
)–
Gat
heri
ng li
ght
–A
ngul
ar r
esol
utio
n
–M
agni
fica
tion
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Lig
ht G
athe
ring
•T
op p
rior
ity s
ince
mos
t ce
lest
ial o
bjec
ts a
re d
im
•T
eles
cope
= “
light
buc
ket”
•K
ey: c
olle
ctin
g ar
ea
•H
uman
eye
–~5
mm
,
•Su
baru
tele
scop
e m
irro
r –
8.3
m
–3
mill
ion
times
the
area
of
your
eye
!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Tel
esco
pes
•A
tel
esco
peco
llect
s lig
ht•
The
larg
er th
e ap
ertu
re, t
he m
ore
light
can
be
colle
cted
in a
gi
ven
amou
nt o
f tim
e
Ape
rtur
e
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ang
ular
Res
olut
ion
•R
evea
l det
ails
of
obje
cts
•A
ngul
ar r
esol
utio
n:–
Mea
sure
s fi
nest
det
ail t
hat i
s no
t sm
eare
d ou
t
–S
mal
lest
ang
le f
or w
hich
two
star
s ar
en’t
sm
eare
d to
geth
er to
on
e •e.
g., h
uman
eye
res
olut
ion
= 1/
60th
of a
deg
ree
•H
ubbl
e Sp
ace
Tel
esco
pe
reso
lutio
n <
1/3
6,00
0thof
a d
egre
e
Low
res
olu
tion
imag
e
Hig
h re
solu
tion
imag
e
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Res
olve
Thi
s
•W
hat i
s th
e lim
itatio
n on
how
wel
l a
tele
scop
e ca
n re
solv
e ob
ject
s?–
The
siz
e of
the
tele
scop
e, s
illy
–T
he d
iffr
actio
n of
a te
lesc
ope
is θ
diff=
1.22
λ/D
•W
e w
ant t
he a
ngle
to b
e sm
all a
s po
ssib
le
•So
, aga
in w
e w
ant a
larg
e te
lesc
ope!
•T
he K
eck
10 m
eter
has
a θ
diff=
0.0
5 ar
csec
–B
ut, t
here
is a
noth
er li
mita
tion!
•T
he a
tmos
pher
e
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Tw
inkl
e, T
win
kle
Litt
le S
tar
•T
urbu
lenc
e in
the
atm
osph
ere
“jig
gles
” im
age
•W
e se
e it
as
sta
rs
“tw
inkl
ing”
•A
stro
nom
ers
use
the
term
se
eing
to d
escr
ibe
the
stea
dine
ss o
f th
e sk
y•
A g
ood
atm
osph
ere
will
al
low
θ∼
1ar
csec
.•
So f
or m
oder
n te
lesc
opes
, w
e ar
e lim
ited
by th
e at
mos
pher
e.ht
tp:/
/ant
wrp
.gsf
c.na
sa.g
ov/a
pod/
ap00
0725
.htm
l
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
•M
akes
the
obje
ct a
ppea
r la
rger
•U
sefu
l for
stu
dyin
g de
tail
•L
east
impo
rtan
t iss
ue–
If y
ou d
on’t
hav
e th
e ot
her
two,
this
is n
ot a
t all
rele
vant
–N
o go
od to
mag
nify
a
blur
ry im
age
•M
agni
fica
tion
is
f o
bs/f
eye∝
D
Mag
nifi
catio
n
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
In T
he E
nd S
ize
Doe
s M
atte
rs
•B
oth
light
col
lect
ing
and
reso
lutio
n im
prov
e as
the
diam
eter
of
the
scop
e –
its le
ns o
r m
irro
r –
incr
ease
s
•B
igge
r is
bet
ter!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Big
ger
Is B
ette
r!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Foc
usin
g
For
dist
ant o
bjec
ts: l
ight
ray
s ar
rive
in p
aral
lel
Tel
esco
pe jo
b:co
llect
ray
s ov
er la
rge
area
focu
s to
a p
oint
then
re-
stra
ight
en o
ver
smal
ler
area
: bri
ghte
r
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Tel
esco
pe T
ypes
•Opt
ical
(vi
sibl
e lig
ht)
•R
efra
ctin
g
•R
efle
ctin
g
•Rad
io, i
nfra
red,
ultr
avio
let
•R
efle
ctin
g
•X-r
ay
•R
efle
ctin
g (g
razi
ng in
cide
nce)
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ref
ract
ion
•L
ight
trav
els
mor
e sl
owly
in tr
ansp
aren
t mat
eria
ls th
an it
doe
s in
vac
uum
•W
hen
pass
ing
from
one
med
ium
to a
noth
er (
e.g.
air
to w
ater
),
light
is b
ent (
refr
acte
d)
air
wat
er
I
R
R<
Iif
spee
d of
ligh
t in
low
er m
ediu
m is
sm
alle
r th
an in
upp
er
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ref
ract
ion
by
pla
tes
vs. b
y le
nse
s
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Fo
cusi
ng
by
len
ses
Lens
axi
s
Foc
al p
oint
Foc
al p
lane
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
A r
efra
ctin
g te
lesc
ope
uses
at
leas
t tw
o le
nses
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ref
ract
ing
Tel
esco
pes:
Len
ses
•U
se L
ense
s–
Cur
ved
glas
s
–L
ight
ben
t to
focu
s
•Pr
oble
ms:
–
Len
ses
focu
s co
lors
diff
eren
tly
–Sa
g •L
arge
lens
dis
tort
ed a
s it
hang
s
•L
imits
lens
siz
e
–L
imite
d w
avel
engt
hs
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
The
Lar
gest
Ref
ract
or
•A
t Yer
kes
Obs
erva
tory
nea
r C
hica
go
•40
inch
dia
met
er le
ns, 6
3½ f
eet l
ong!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Tel
esco
pe
mo
un
ts
Alti
tude
-azi
mut
h (a
lt-az
imut
h)E
quat
oria
l
Mor
ehea
d P
lane
tariu
mF
eb 1
6, 2
005
Ast
rono
my
210
Spri
ng 2
005
Ref
lect
ion
Sm
oo
th s
urf
ace
Ang
le o
f inc
iden
ce I
= A
ngle
of r
efle
ctio
n R
Ro
ug
h s
urf
ace
IR
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Foc
usin
g by
mir
rors
Mirr
or a
xis
Foc
al p
oint
Foc
al p
lane
Sp
her
ical
ab
erra
tio
nO
ccur
s w
hen
sect
ion
of a
sph
ere
is u
sed
inst
ead
of a
par
abol
oid
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ref
lect
ing
Tel
esco
pes
•U
se M
irro
rs–
Sag
not a
pro
blem
–su
ppor
t the
m
irro
r fr
om b
elow
–Pa
rabo
lic
mir
ror
give
s go
od f
ocus
•T
oday
, all
larg
e pr
ofes
sion
al
tele
scop
es a
re r
efle
ctor
s
Hu
bb
le T
eles
cop
e M
irro
r (2
.4 m
)
Kec
k T
eles
cop
e M
irro
r(1
0m)
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ref
lect
ing
tel
esco
pe
des
ign
s
New
toni
an
Cas
segr
ain
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
The
Lar
gest
Ref
lect
or
•K
eck
Obs
erva
tory
on
Mau
na K
ea in
Haw
ai’i
•T
win
10-
met
er r
efle
ctin
g te
lesc
opes
•C
ompl
eted
199
3 &
199
6
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Gem
ini T
eles
cope
s
•T
win
tele
scop
es•
One
in H
awai
i, on
e in
Chi
le•
8-m
eter
mir
rors
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Kitt
Pea
k, A
rizo
na
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Cer
ro-T
elol
oIn
tera
mer
ican
Obs
erva
tory
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Ast
rono
my
as a
Hob
by
•D
id y
ou k
now
you
can
see
a g
alax
y 2½
m
illio
n lig
ht-
year
s aw
ay
with
you
r un
aide
d ey
es?
•O
r th
at y
ou
can
see
crat
ers
on
the
Moo
n w
ith
bino
cula
rs?
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
You
r F
irst
Ste
ps…
•R
ead
–T
he n
ight
sky
is b
eaut
iful
to
beho
ld, b
ut a
stro
nom
y is
a
lear
ning
hobb
y–
You
can
fin
d go
od g
uide
s to
th
e ni
ght s
ky a
t you
r lo
cal
libr
ary
or b
ooks
tore
–G
et a
cop
y of
Sky
& T
eles
cope
from
the
libra
ry•
Off
ers
a bi
g ev
enin
g-sk
y m
ap f
or b
egin
ners
•Pr
actic
al o
bser
ving
tips
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Lea
rn T
he S
ky
•L
earn
the
sky
wit
h th
e na
ked
eye
–D
ownl
oad
star
cha
rts
from
Sky
& T
eles
cope
–B
uy a
pla
nisp
here
from
a b
ooks
tore
–G
ener
ate
sky
char
ts w
ith th
e St
arry
Nig
ht
soft
war
e th
at
cam
e w
ith y
our
text
book
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Star
t With
Bin
ocul
ars
•B
inoc
ular
s ar
e an
idea
l fi
rst t
eles
cope
–W
ide
fiel
d of
vie
w, m
akin
g it
easy
to f
ind
your
way
ar
ound
–R
elat
ivel
y in
expe
nsiv
e–
Wid
ely
avai
labl
e–
Eas
y to
car
ry a
nd s
tore
–A
llow
you
to e
asily
see
luna
r cr
ater
s, J
upite
r’s
moo
ns,
and
the
brig
hter
sta
r cl
uste
rs, g
alax
ies,
and
neb
ulae
–T
he la
rger
the
fron
t len
ses
are
the
bette
r
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Seek
Out
Oth
ers
•T
here
are
two
amat
eur
astr
onom
y cl
ubs
here
–U
nive
rsity
of
Illin
ois
Ast
rono
mic
al S
ocie
ty–
Cha
mpa
ign-
Urb
ana
Ast
rono
mic
al S
ocie
ty
•A
ttend
sta
r pa
rtie
s w
here
you
can
mee
t m
embe
rs a
nd d
iscu
ss a
stro
nom
y–
Try
out
dif
fere
nt ty
pes
of te
lesc
opes
–G
et a
dvic
e
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
You
r O
wn
Tel
esco
pe
•W
hen
you’
re r
eady
, its
tim
e fo
r yo
ur o
wn
tele
scop
e•
Don
’t s
kim
p on
qua
lity
, you
’ll
regr
et it
late
r•
Wha
t do
you
wan
t?–
Solid
, ste
ady,
sm
ooth
ly w
orki
ng
mou
nt
–H
igh
qual
ity o
ptic
s–
Lar
ge a
pert
ure
–bu
t not
too
larg
e,
you
have
to c
arry
it!
–T
he b
est t
eles
cope
for
you
is th
e on
e yo
u'll
use
mos
t!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Rel
ax a
nd H
ave
Fun
!
•T
his
is th
e m
ost i
mpo
rtan
t ste
p!•
Tak
e pl
easu
re in
wha
teve
r yo
ur
eyes
, bin
ocul
ars,
or
tele
scop
e ca
n sh
ow y
ou•
The
mor
e yo
u lo
ok, t
he m
ore
you
will
see
, and
the
mor
e yo
u w
ill b
ecom
e at
hom
e in
the
nigh
t sky
•Se
t you
r ow
n pa
ce, a
nd r
evel
in
the
beau
ty a
nd m
yste
ry o
f ou
r am
azin
g un
iver
se!
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Lig
ht P
ollu
tion
•A
noth
er p
robl
em
for
astr
onom
ers
is
light
pol
lutio
n
•C
ity li
ghts
rai
se
the
“bac
kgro
und
light
” le
vel
•M
akes
it m
ore
diff
icul
t to
colle
ct
light
fro
m s
tars
Tucs
on, 1
959
Tucs
on, 1
989
Feb
16,
200
5A
stro
nom
y 21
0 Sp
ring
200
5
Tw
inkl
ing
& L
ight
Pol
lutio
n
How
do
we
com
bat t
hese
pro
blem
s?ht
tp:/
/ant
wrp
.gsf
c.na
sa.g
ov/a
pod/
ap00
0725
.htm
l
Tucs
on, 1
959
Tucs
on, 1
989
