Telescope Projects at Steward
Observatory
Work in Progress
Astronomical Society of New York
Union College
Saturday, 24 October 2009
Peter Wehinger
Steward Observatory
University of Arizona
Casting a 6.5-m Mirror for San Pedro Martir
Steward Observatory Mirror Lab
A World Class Site: San Pedro Martir
Baja California, Mexico
Peter Wehinger
Hexagonal
Columns
of
Al2SiO5
Honeycomb
Structure
Light-weight
Spun-cast
Casting in
Progress –
26 Aug 2009
SPM 6.5-m
Mirror
The Principals
UNAM
INAOE
UC Berkeley
UC Santa Cruz
U Arizona
San Pedro Martir
A World Class Site
Peter Wehinger
Steward Observatory
SOML Casting Event – 6.5-m Mirror
26 August 2009
Baja California and the Sonoran Desert
San Diego
~ 600 km
Ensenada
380 km
SPM
Tucson
Road to San Pedro Martir
SPM Obs
Meling Ranch
Airfield
60 km
Pico del
Diablo
Climatic & Seeing Conditions
Clear Sky Statistics
• Photometric
~ 63% (Tapia et al)
• Satellite Imaging ~ 73% (Erasmus et al.)
• Spectroscopic
~ 81% (Tapia et al.)
Seeing Statistics
•
Median Seeing
~ 0.48 arc sec
•
Mean Seeing
~ 0.57 arc sec (FWHM)
•
25th Percentile
~ 0.37 arc sec
NIGHT SKY IN THE DESERT
N
Lick
Lowell
LA
PHX
LBT
TUC
Palomar
San Pedro
Martir
Kitt
Peak
MMT
HER
SPM Sky brightness B ~ 22.3
San Diego
N
Yuma
Tijuana
Ensenada
San Felipe
SPM
Sky Brightness at
San Pedro Martir
Darker than
B ~ 22.3 mag/sec2
300 km
300 km
Intensity (erg/s/cm2/A)
Night Sky Spectrum on San Pedro Martir
l (A)
Remarks about SPM Night Sky
• Integrated Light of Night Airglow Green Line [OI] 5577
visible to ~10-15 deg above horizon
• Arcturus – steady, no scintillation (twinkling)
• Naked-eye limit at least ~ 7th magnitude
• 10-12 of brightest galaxies in Virgo Cluster - visible
• SPM has darkest night sky – Compared with other sites
Arizona, Chile, Hawaii, Himalayas
Possible Air Field at Vallecitos ~ 5-6 km from telescopes
2425 m
2 km
2434 m
LBT
LARGE BINOCULAR
TELESCOPE
Site: Mt Graham, Arizona
Two 8.4-m f/1.1 Mirrors
Steward
Observatory
Mirror Lab
Casting Bay
6.5-m
8.4-m
8.4-m
LBT Edge-to-Edge ~ 22.4 m, Equivalent Circular Aperture ~ 11.8 m
30 m
NGC 6946 with 8.2-m Subaru
NGC 6946 with 8.4-m LBT
GMT
GIANT MAGELLAN TELESCOPE
Site: Las Campanas, Chile
GMT
• seven 8.4-m Mirrors
• 21.5-m Circular Aperture
• 25.5-m Edge to Edge
Graphics by Todd Mason
GMT Partners as of Oct 2009 • Carnegie Institution of Washington
• University of Texas at Austin
• Texas A & M University
• University of Arizona
• Australian National University
• Astronomy Australia Ltd.
• Harvard University
• Smithsonian Institution
• Korea Astronomy & Space Institute
+ 1-2 others considering joining
Mirror Lab Founder, Roger Angel
inspects 8.4-m mirror for GMT
GMT-1– polishing at ~ ±0.5 m, 16 Oct
2009
Final figure will be ±10-20
nm,
400x smoother
When GMT is completed
in ~ 10-12 years
• What will be found…?
• Remember Hale & Wickliffe Rose
• Again there will be many surprises..!
Three Planets
b, c, & d
Imaged around
Star HR 8799
Light from central
star is suppressed
Discovery
Announced
14 Nov 2008
Gemini 8.2 m
Phil Hinz et al. Steward Observatory
LSST
LARGE SYNOPTIC SURVEY
TELESCOPE
Site: Cerro Pachon, Chile
Founding Partners (2003)
• University of Arizona
• Research Corporation
• University of Washington
• NOAO
• + 18 other institutions
(as of 2008)
Large Synoptic Survey Telescope
3.4 m
Secondary
64 cm
Focal Plane
Field
Flattener
LSST
Optical
Layout
Tertiary
f/0.8
6.28m
4.96 m
Primary
f/1.25
8.36 m
Design: L. Seppala, LLNL
Filters
Large Synoptic Survey Telescope
Project Overview & Goals
• 10-sec exposures ~ 24 mag.
• 3.5 Gpix/image – 10 sq. deg
• 30-40 Terabytes per night
• Entire sky surveyed in 4 nights
• Search for Near-Earth Objects
• Survey the Kuiper Belt
• Probe dark matter
• Many Surprises
• Serendipitous Discoveries
LSST
8.4-m Primary Mirror
22 October 2008
Lifting off oven floor
Weight ~ 52 tons
Glass ~ 26 tons
LSST
8.4-m Primary Mirror
22 October 2008
During move from oven
to holding ring
Weight ~ 103,000 lbs
Glass ~ 52,000 lbs
Ground-Layer Adaptive Optics
Recent Results on MMT
Planet found
around the
Nearby star
b Pictoris
ESO 8.1-m
Telescope
The MMT multi-laser GLAO system
Laser type
2 x doubled YAG (15 W each)
Wavelength
532 nm
Pulse rep rate
5.2 kHz
Average power
30 W
Launch location
Behind secondary mirror
Number of beacons
5, arranged like a pentagon
Enclosed field of view 2 arc minutes
Beacon type
Rayleigh scattering
Range gate
20-29 km, dynamic
MMT results: M3
110”
Open loop, Ks filter, seeing 0.70”
Logarithmic scale
MMT results: M3
110”
Closed loop GLAO, Ks filter, seeing 0.30”
Logarithmic scale
NGC 2770 – First Light Binocular Image with LBT
Gamma-Ray Burst
Supernova
11 Jan 2007
Optical Images of X-ray Nova XTE J1550-564
Magellan 1 6.5-m Telescope (Baade)
Las Campanas Observatory
VLT UT1 8-m Telescope
& FORS 1: ESO
1
Paul Groot, Harvard-Smithsonian
Center for Astrophysics
Jerome Orosz, University of Utrecht