New%20Solar%20Telescope%20in%20Big%20Bear%20Solar%20Observatory

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New Solar Telescope in Big Bear Solar Observatory

• Philip R. Goode
• Big Bear Solar Observatory
• Center for Solar-Terrestrial Research
• New Jersey Institute of Technology

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Motivations for NST

• Fundamental Scale of Solar Magnetism
• Solar magnetic field (bundled) fibers
• Flares and CMEs origins
• Satellite data a complement
• Space Weather
• Solar storms can damage space assets and
  terrestrial telecommunications/power grid
• Telescope Technology Challenges
• Off-axis Telescope
• Heat Control
• Adaptive Optics

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New Solar Telescope (NST)

• Collaborators
• UHawaii
• UArizona
• KASI/SNU

• Federal Funding
• NSF
• AFOSR
• NASA
• KoSF

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BBSO/NSTers
Roy Coulter
Nicolas Gorceix
Jeff Nenow
John Varsik
Sergey Shumko
Mark Vincent
Vlad Abramenko
Randy Fear
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BBSOers
Erika Norro
Vasyl Yurchyshyn
Valentyna Abramenko
Chang Liu
Alla Shumko
Mark Klebba
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Atmospheric Seeing

• Why BBSO Site?
• The character of the seeing at Big Bear differs
  markedly from the high altitude, volcanic island
  sites measured in the ATST site survey.
• The NST primary mirror, at 14 m, will be above
  the 8 m height of the detector system used to
  take these data.

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Big Bear Solar Observatory BBSO was built by
Caltech in 1969. The dome sits at the end of a
1000 ft. causeway on Big Bear Lakes north shore
at 6,750 foot elevation. Observatory was
transferred from Caltech to NJIT in July 1997.
The surrounding waters
of Big Bear
Lake reduce
ground level
convection,
and predominate
winds
bring smooth air flows

across the flat surface of
the lake providing superb conditions for solar
observing.
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Telescope
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Big Bear Solar Observatory New Solar Telescope
The New Solar Telescope Polarimeters and
SNU-FISS Spectrograph
Instrumentation Two instrument stations will be
used with the NST The coude lab provides
stable optical benches in a temperature
controlled environment. A spectrograph and 2
magnetographs are planned for the initial
observing campaigns. The coude will be fed by
the adaptive optics module allowing
diffraction-limited imaging at all wavelengths.
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NSTs Place Under the Sun

• NST Science
• High-resolution, high-cadence studies of solar
  flares
• Structure/evolution of magnetic fields in flaring
  active regions
• Dynamics of kGauss flux tubes
• Magneto-convection in sunspots
• Heating of the upper atmosphere
• Upgraded instrumentation (2nd generation)
• New (imaging) polarimeters (IR visible)
• Real-time image restoration
• Spectrograph - FISS
• Adaptive optics
• By 2008 Ready to solve many space weather
  problems
• SDO, STEREO and Solar-B in space (0.5 m
  telescope in space)
• 1.01.5 m telescopes in Europe (THEMIS, SST,
  GREGOR)
• No ATST before 2016

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NST BBSO/UH/KASSI/UA

• 1.6 m clear aperture (1.7m blank) being figured
  by Steward Mirror Lab
• Active optics (36 actuators in PM mirror cell) to
  control thermally induced variations airknifes,
  backside cooling
• Primary f/ 2.4, 4.4 m telescope length, lt20 nm
  surface quality, lt10 Å µroughness, and blank of
  Zerodur with CTE of (0.01.0) ? 10-7 per C
• Observable wavelengths 0.391.6 µm with AO and
  gt0.39 µm without AO
• FOV 180 in optical labs or 1/2 in prime focus
• Realtime telescope alignment
• Polarization, wavefront sensing and calibration
  optics immediately before M3
• Diffraction limit 0.06 _at_ 0.5 µm and 0.2 _at_ 1.56
  µm

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Primary Mirror
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Optical testing measuring aspheric surfaces

• Interferometers use light to measure to 1 nm
  surface errors, for spherical or flat surfaces
• We need to measure aspheric (non-spherical)
  surfaces
• CGH can change spherical wavefronts to aspheric,
  allowing the use of interferometers for measuring
  aspheric surfaces

Aspheric surface to be measured
aspherical wavefront
Spherical wavefront
Interferometer
CGH
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Optical test for NST mirror
50 cm mirror
10 cm CGH
15 cm lens
4D interferometer
10 µm alignment tolerances
1.7-m primary mirror Off-axis piece of f/0.7
parent
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Mirror Testing
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Test Tower
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PM Final Figuring
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Residual Figure Errors
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Active Optics

• The primary mirror is supported by 36 axial and 6
  tangential actuators. These force based servos
  will compensate for gravity and thermally induced
  errors in the mirror figure.
• A wavefront sensing system is being developed to
  control the active optics components.
• Realtime telescope alignment, fast tip/tilt and
  M1 figure control

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Primary Mirror (M1) Thermal Control

• Function Mitigate mirror seeing

seeing
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Big Bear Solar Observatory New Solar Telescope
Telescope Design
The NST is an off-axis section of 5.3 meter,
f0.73 Gregorian telescope. The result is an
f2.4, 1.6 meter system. The design offers an
unobstructed pupil allowing superior adaptive
optics performance and low scattered light. The
prime focus, where most of the solar radiation
must be reflected/absorbed, is accessible without
obstructing the light path. A small (3.5 mm)
field stop (UH) at prime focus limits the
radiation loads transmitted to the downstream
optics. Polarization optics before M3
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Adaptive Optics
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Adaptive Optics
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Big Bear Solar Observatory
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Optical Support Structure
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Dome Removal
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New Dome
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Old Telescope Removal
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Fly Away
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Fork and Spectrograph, etc.
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Empty Dome
Ala Saadeghvaziri
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New Pier
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New Pier
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Secondary Mirror(s)

• SM is Zerodur from Schott (plano-plano)
• Space Optics Research Lab has figured 0.5 m
  mirror on axis
• Cut into two concave elliptical SMs (140 and 145
  mm)
• lt20 nm surface quality and foci downstream at
  f1300 0.5 mm (if measured from on-axis mirror
  optical center) and f26482 10 mm
• Mirrors silver coated
• Mirrors in BBSO and were tested in UA Mirror Lab
  in Summer 2007

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Prime Focus
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Nasmyth Focus
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Telescope Control System
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Collaborate and Plan for SuccessFirst Light
Work

• High Order Adaptive Optics
• National Solar Observatory/KIS collaboration
• Nasmyth Teledyne Camera
• KASI Park, Young-Deuk
• FISS Installation/Operation
• SNU Chae, Jongchul
• VIM/IRIM
• NJIT - Park, Sung-Hong
• Far IR
• Boulder/Tucson/BB collaboration
• WFS, Polarization, etc.
• Your Project???

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Big Bear Solar Observatory New Solar Telescope
Timeline
Dome complete Mar. 2008 OSS Delivery May
2008 PM Delivery Apr 2008 Telescope
Installation May 2008 First Light - May
2008 Full operation Spring 2009