Subaru Telescope before and after the earthquake
Daigo Tomono and members of Telescope Engineering Division
2007-03-23
Agenda
TimelineSubsystems affected– Az axis– IR secondary mirror– Primary mirror support?
Optical adjustments– M2 position– Pointing
Timeline - first shakeTimeline - first shake
500500
10001000
15001500
20002000
25002500
30003000
07:08:0007:08:00 07:09:0007:09:002006-10-15 HST2006-10-15 HST
FX1FX1FX2FX2FX3FX3
Forc
e (N
)Fo
rce
(N)
2007-03-23
Timeline07:08:00 HST– Oil bearing active– M1 felt the shake– DG started
07:20– UPS for OCS
workstations drained10:00-11:00– Power to telescope
control system (TCS) stopped
2007-03-23
Timeline12:00– First staffs arrived– Power for TCS
supplied by diesel generator
14:30– HELCO power
recovered16:00– Recovered network
connection
Timeline - gathering records
2007-03-23 Subaru Telescope (Tomono) 7
Physical recoveryOct 15– Heat exhaust systems– Az & El oil bearings– M1 cover– CsOpt M2– Instrument rotator
Oct 16– El axis– AG/SH cameras– Calibration units
Oct 17– El axis– ADC– M3– AG/SH prove– Dome flat source– Balancer
Oct 22– Az axis drive
Oct 24– 1st observation
Nov 2– IRM2
2007-03-23
Subsystems affected
Az axisIR secondary mirror– Sitting in the dome
Primary mirror support?
Main shutterObservation floor doorNsIR instruments
2007-03-23
Damage on Az axis
Copyright 2003 META Corporation Japan #150102
www.auto-met.com
Damage on Az axis
Telescope moved 1.2mm towards EES (20 deg to S from E)
500t
2007-03-23
Damage on Az axis
Center hub shiftedBroken grout
Damage on Az axis
Moved encoder tape following the telescope
Primary mirrorDamage on IR secondary mirror
Damage on IR secondary mirror
Photo by Satoru Negishi
2007-03-23
Damage on IR secondary mirror
Replaced the mechanical fuse
2007-03-23
Primary mirror support?
While tilting the telescope ...BIG SOUND heard
Force to fixed points?Released displacements with extracting actuators
-40000
0
4000
-2
-1
x(mm, opt+)y(mm, rear+)
Forc
e ch
ange
(N) FX1
FX2
FX3
2007-03-23 Subaru Telescope (Tomono) 17
Optical adjustments
Many configurations– 12.5 of 28 ready as of
March 2007– 3-4 hours for each
Adjustment of M2 position– Mechanical shift of
5mm at somewhere between M1 and M2
Pointing analysis– By the earth quake
• Az zero point: 72"• El zero point: 14"
– Long term drift• El zero point• EW misalignment of Az
axis
Adjustment of M2 position
Gradient of PSF on wide field instrumentsOffset M2 shadow
2007-03-23 19
Adjustment of M2 positionOff-axis SH test– Measures defocus
around the telescope field of view
Mechanical field of view
Best focal sphere
2007-03-23
Adjustment of M2 position
-5
0
5
-10 -5 0 5 10
Front -y(mm) -Rear
IR - x(mm) - Opt
Cs(IR)Cs(CsOpt+ADC)
Cs(CsOpt)NsIR(IR+ImR)
NsOpt(Opt+ADC)NsOpt(Opt+ADC+ImR Red)
NsOpt(CsOpt)NsOpt(CsOpt+ADC)
NsOpt(NsOpt+ImR Blue)NsOpt(NsOpt)
Fron
t -y(
mm
) -R
ear
Off-axis SH test– Measures defocus
around the telescope field of view
Detected shifts of M2 in relation with M1
2007-03-23 Subaru Telescope (Tomono) 21
Pointing analysis
75
60
45
30
10"
N
E
S
W
Example:– Nov 17– Prime focus
2007-03-23 22
Az zero point
0.31
0.315
0.32
0.325
0.33
0.335
0.34
0.345
0.35
0.355
2000 2001 2002 2003 2004 2005 2006 2007Year
A0:
Az
zero
poi
nt o
n C
s (d
eg)
2007-03-23 23
El zero point
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
0.022
0.024
0.026
2000 2001 2002 2003 2004 2005 2006 2007Year
A1:
El z
ero
poin
t on
Cs(
IR) (
deg)
2007-03-23 24
NS misalignment of Az axis
-0.007
-0.006
-0.005
-0.004
-0.003
-0.002
-0.001
0
0.001
2000 2001 2002 2003 2004 2005 2006 2007Year
A2:
NS
mis
alig
nmen
t of A
z ax
is o
n C
s (d
eg)
2007-03-23 25
EW misalignment of Az axis
-0.003
-0.0028
-0.0026
-0.0024
-0.0022
-0.002
-0.0018
-0.0016
-0.0014
-0.0012
-0.001
2000 2001 2002 2003 2004 2005 2006 2007Year
A3:
EW
mis
alig
nmen
t of A
z ax
is o
n C
s (d
eg)
2007-03-23 26
Non-perpendicularity: Az & El
-0.05
-0.04
-0.03
-0.02
-0.01
0
0.01
0.02
2000 2001 2002 2003 2004 2005 2006 2007Year
A4:
non
-per
pend
icul
arity
of A
z an
d E
l on
Cs
(deg
)
2007-03-23 27
Non-perpendicularity: El & optics
-0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
2000 2001 2002 2003 2004 2005 2006 2007Year
A5
on C
s(IR
) (de
g)N
on-p
erpe
ndic
ular
ity o
f El &
poi
ntin
g ax
es
2007-03-23 28
Tube flexure
-0.005
-0.0045
-0.004
-0.0035
-0.003
-0.0025
2000 2001 2002 2003 2004 2005 2006 2007Year
A6:
Tub
e fle
xure
on
Cs(
IR) (
deg)
2007-03-23 Subaru Telescope (Tomono) 29
Concerns
Power supply– Unknown cause of power failure to telescope
control system– Power failure protection not well tested
M2 shift– Where is the mechanical shift?
Summary
Physical damages– Az axis– IR secondary mirror
Optical parameters– Az zero point: 72"– El zero point: 14"– M2 shift of: 5 mm
Physical damages– Az axis– IR secondary mirror
Optical parameters– Az zero point: 72"– El zero point: 14"– M2 shift of: 5 mm