1. 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

2. Big Bear Solar Observatory 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 III VI IV V

3. Big Bear Solar Observatory 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

4. Big Bear Solar Observatory 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

5. Big Bear Solar Observatory 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

6. Big Bear Solar Observatory III. Adaptive Optics (AO76)

7. Big Bear Solar Observatory 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

8. Big Bear Solar Observatory 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

9. Big Bear Solar Observatory 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)  NaD 2 (588.9 ± 0.15 nm )  Cadence: < 15 s Courtesy : C. Denker and A. Verdoni

10. Big Bear Solar Observatory 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 : 1.4×10 5  60 ” Scanning cadence : 60 sec.  Dual-band spectra using dual CCD cameras  Echelle grating with order-selecting filters