big bear solar observatory nst main features all reflecting, off-axis gregory optical configuration...

Big Bear Solar Observatory

NST Main Features All reflecting, off-axis Gregory

optical configuration PM: 1.6 m clear aperture with f/2.4 Figuring PM to 16 nm rms Effective focal length: 83.2 m (F/52

at Gregorian focus) FOV: 3' in prime focus Wavelength range from 380 nm to

1.7 µm in Coudé lab with AO PM active thermally controlled Integrated active optics (ao) and

adaptive optics (AO) Quasi-static telescope alignment Diffraction limited: 0.06″@ 500 nm

and 0.2″@ 1.56 m with AO WFS, polarization and calibration

optics immediately before M3 Facility-class instruments


NST Scientific Instruments Nasmyth Focus Instruments

I. Nasmyth focus broad band filtergraphs

Gregorian Focus Instruments

II. Cryogenic infrared spectrograph (CIRS)

Coudé Lab Instruments

III. Adaptive optics (AO)IV. Infrared imaging

magnetograph (IRIM)V. Visible imaging

magnetograph (VIM)VI. Fast imaging solar

spectrograph (FISS)

I

II

IIIVI

IV V


I. Nasmyth Focus Filtergraph First-light scientific instrument Serves as scientific analysis and

engineering feedback Nasmyth prime focus Local correlation tracker (tip/tilt) FOV: 70″by 70″(square) Visible photometry

PCO camera 2K by 2K TiO 705.7 nm BF, FWHM 10 Å G-band 430.5 nm BF, FWHM 5.0 Å H Lyot NF, FWHM 0.25 Å Ca II K 393.3 nm NF

Near infrared photometry Rockwell camera 1K by 1K 1.6 m BF, FWHM 25 Å (deep layer) 2.23 m BF (cold clouds) 1.083 m NF (corona hole)

I


First-light Scientific

Observations

Courtesy : F. Wőger and KISIP v.6

TiO 705.7 nm, FWHM 10 Å quiet sun H, FWHM 0.25 Å blue wing


III. Adaptive Optics (AO) AO-76 which was used for BBSO

65 cm telescope, is a collaboration with NSO (T. Rimmele)

Shack Hartmann WFS with 76 sub-apertures (AO-76)

Xinetics Deformable Mirror with 97 actuators

High speed Baja camera with a frame rate of 2500 frame/s

Bitware Hammerhead Boards with 40 digital signal processors (DSPs)

Closed-loop Bandwidth: 120 Hz Strehl ratio: 0.7 in the NIR under

median BBSO seeing


III. Adaptive Optics (AO76)


III. Adaptive Optics System

What’s Next ? AO-76 transition from BBSO 65 cm to NST AO-76 installation, calibration and optimization AO-76 routine operation for NIR and visible observation

Strehl ratio: 0.7 in the NIR under median BBSO seeing

AO-308 system development in collaboration with NSO Wave front sensor design, upgrade control system, matrix

reconstruction Streho ratio: 0.8 in the NIR under median BBSO seeing Strehl ratio: 0.35 in the visible under median BBSO seeing

AO-308 installation, calibration and optimization AO-308 routine operation for NIR and visible observation MCAO development in collaboration with NSO and

KIS Courtesy : T. Rimmele

AO-76

AO-308

VIS NIR

VIS NIR


IV. IR Imaging Magnetograph NIR Fabry-Pérot etalon plus Lyot

filter and interference filter Wavelength coverage: 1 – 1.7 m Band pass: 10 pm Telecentric optical configuration Field of view: 75” by 75” Available spectral lines:

Fe I 15648.5 Ǻ Fe I 15652.9 Ǻ

Polarimeter: rotating wave plate ahead of M3

Spectrometric cadence: < 15 s Polarimetric cadence: < 2 min


V. Visible Imaging Spectrometer Single Fabry-Pérot etalon plus

narrow band interference filter Spectrometer before NST AO-308

installation Wavelength coverage: 550 – 700 nm Band pass: 7.2 pm Telecentric optical configuration Field of view: 45” by 45” Available spectral lines:

H(656.3 ± 0.15 nm ) Fe I (630.2 ± 0.15 nm) NaD2 (588.9 ± 0.15 nm )

Cadence: < 15 s

Courtesy : C. Denker and A. Verdoni


VI. FISS FISS – Fast Imaging Solar

Spectrograph A collaboration between BBSO and

Korean Solar Community Focus on fine structures of

chromosphere: filaments, spicules, mottles, jets microflares …

Slit-scan imaging spectrograph Quasi-Littrow configuration Spectral resolution : 1.4×105

60 ” Scanning cadence : 60 sec. Dual-band spectra using dual CCD

cameras Echelle grating with order-selecting

filters

big bear solar observatory nst main features all reflecting, off-axis gregory optical configuration...

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