YunNan One Meter Infrared Solar Tower

Jun Lin

Why is YNST?

After Solar-B launch, what can we do by using of ground-based telescope ?

Detailed chromosphere diagnostics

Special magnetic field observations (IR, hyperfine-structure of atoms)

Higher angle resolution

----- B. W. Lites ( at THEMIS user meeting )

What is YNST?

• An optical system of 1-meter aperture: resolution < 0.3 arcsec (200 km), vacuum tube, AO

• Symmetric structure for accurate measurement of magnetic field:

Gregorian telescope, 10-4 polarization analyzer, I, Q, U, V

• Focal instrument of high resolution: Filter-based image Fabry-Perot filter, magnetograph, high spectral resolution

• Multi-wavelength observations: Multi-wavelength spectrograph, Near-Infrared detectors • High accuracy tracking and pointing system: Auto guiding system, correlating tracker

YNST’s Spectral Range

• The Sun will be observed within the range from 3,000 to 25,000 Å.

• This range spans the spectrum from UV to near IR.

• Information includes those of the photosphere, the chromosphere, and the corona.

• Spectral lines include both magnetic field and plasma flow sensitive ones.

Location of the FUXIAN LAKE

Fuxian lake

Look at the Fuxian Lake from Space

General Information of Fuxian Lake & Cape Eagel

• The distance from Kunming City: 60 km

• Altitude: 1712 m

• Longitude: 102°57'11"

• Latitude: 24°34'47"

• Maximum Width: 11.5 km

• Maximum Length: 31.5 km

• Maximum Depth: 155.0 m

• Surface Area: 211.0 km2

• Number of Clear Days/year: > 275

• Average Wind Speed: < 6 m/s

• Water Integration : 11mm (average over a year)

• Average r0: 12.3 cm (average over a year), 11.5 cm ( median of a

year)

Observatory Site Looking from Distance

N

ES

W

YNST

Internal and External Structures of the Building for YNST

YNST’s Optical System

Parameters for Each Component(F/45.9 Modified Gregorian System)

• Window glass: H = 65 mm, D = 1,200 mm

• M1 : D = 980 mm, F/2.45 (paraboloid)

• M2 : D = 257.8 mm, F/9 (ellipse,-0.327)

• M3 : D = 234.3 mm, F/45.9 (ellipse,-0.453)

• M4 : 43.4 mm × 65 mm (flat)

• Exit pupil: D = 152 mm M5

• View field: 3 arcmin

• Alt-azimuth mount, friction transmission

Spectrograph and Other Instruments

Multi-wavelength spectrograph

Other instruments

H 6563

CaII 8542

HeI 10830

To adaptive lab

Parameters for Spectrometer

Grating constant: 1200 g/mm; Blaze angle: 36 °48'; Incident angle: 33.5Collimating concave mirror f = 6000 mm Focusing concave mirror f = 5000 mm

Lines Orders Wavelength(Å) Diffraction Angle(°) Linear Dispersion(Å/mm)HeD3 1 5878 8.81 1.647 H 1 6563 13.63 1.620 CaII 1 8542 29.18 1.455 (Filter-based image, absence in ONSET)HeI 1 10830 48.39 1.107FeXIII ? 10746+10798 ? ?H 2 3646 18.85 1.577K+H 2 3934+3968 23.08 1.533H 2 4861 37.93 1.315D1, 2 2 5885 59.13 0.855G-band ? 4300~4310 ? ?Fe I ? 6301.5+6302.5 ? ?

Spectral Lines of Interest (Ph+Ch)

• FeI (6301.5+6302.5): Photospheric line sensitive to magnetic field.

• H: Traditional line used to observe flares.• CaII (8542): Chromospheric line sensitive to magneti

c field.• HeI (10830): Good for observations of the filament

magnetic field.

YNST’s Scientific Goals & Tasks

• Observational data of high resolutions in both time and space for magnetic field of fine structures.

• Properties of tiny fibrils, or flux tubes of kilo-gauss magnetic field.

• Coupling of magnetic field and mass motions, and energy transportation from the photosphere to the corona.

• Conducting multi-wavelength observations and data analyses; providing forefront observational data and opportunities to the research communities.