The echelle spectrograph of 1.78m telescope in Gaomeigu

Jiang Shi YangNAOCCAS

The 1.78m Telescope

• It is a high angular resolution telescope with adaptive optics so that can keep the image size smaller than 0.1"

• It has several coude rooms with focal ratio of 200

• It is an alta-azimuth type telescope•

The old Echelle spectrograph of 216 • 216 Coude F/45, 2.12"/mm

• R2 echelle 128mm256mm , beam size 90 mm • Double beam: blue 79l/mm; red 31.6l/mm• Blue 330-580nm, 39-67, total 28 orders• Camera f = 237, 640, 2500mm;• CCD 2p= 48, R=12,000, 44,000, 170,000, • Slit width (SW) =2.66",0.99",0.25"• Cross Dispersion UBK7 prism • Red 520-1100nm; 60-95, total 36 orders • Camera f = 190, 550, 2500mm, CCD 2p= 48 • R=9,620, 37,812, 170,000, ZF3 cross dispersion• SW=3.3",1.15",0.25"• Overall light efficiency 0.02/0.03 for f=(640/550)mm camera. 1

k1k CCD partial cover

Old Echelle spectrograph of 2.16330-1100nm, R:10000-100000

图 1　 216 折轴分光仪光路平面图

216 Coude Echelle spectrograph, Before Slit

SONG echelle spectrograph• Telescope 1m, F/15, 13.75"/mm• R4 beam size 75mm, 31.6l/mm• CCD 2p=0.027mm, R 100,000,

SW = 1.3"• Wavelength range 400-680nm, • Prism cross dispersion, • CCD 2k by 2k 13.5, partial

cover

Move ESp from 216 to 178• 1. Change F/200 to F/45, 2.575"/mm• 2. Change dichroic from 550nm to 680nm• 3. Re-coating all the optics• 4. Renew the 2 echelles to 31.6l/mm, • Blue 400-700nm, order 80-140, 61 orders• Camera f=237,640,2500mm, CCD2p=20• R=39,836, 106,045, 458,114, Ion cell• SW=1.35",0.50", 0.125" , 2k2k 10 CCD • Red 680-1000nm, order 56-83, 28 orders• Camera f=190,550,2500mm, CCD2p=20• R=31594, 91715, 458114• SW=1.68",0.58",0.125", 1k4k 10 CCD

In and out• Need 500,000 RMB• Need 2k2k 10 CCD for blue arm &

1k4k 10 CCD for red arm• Blue RV, Red spectra simultaneously• R=100,000, CCD 2p = 20, SW=0.5", if no

adaptive optics, slit efficiency only 40% • Real gain to SONG: 1.7820.4=1.3• With adaptive optics, the gain is 3.17

Only use 1 beam• Take away the dichroic filter• Only use the red arm: 400-1000nm, 56-140, 85

orders, Ion cell• Camera f=190,550,2500mm, CCD2p=18• Reciprocal Dis. =1.598, 0.552, 0.12nm/mm• R=35,104, 101,895, 509,010• SW=1.51",0.52", 0.113"• M=56, =18nm, need 11.3/32.5mm CCD to c

over the whole range for f=190/550 camer• 2k4k 9 CCD, STL11000MC1, $8795

In & Out• Need 200,000RMB • Need 2k4k 9 CCD, Such as STL-11000M

or U16 (a little too large on one way) or MEGAPLUS ES 1100, QE <0.5

• R=100,000, CCD 2p = 18, SW=0.52", if no adaptive optics, slit efficiency only 42%

• Real gain to SONG: 1.7820.42=1.33• With adaptive optics, the gain is 3.17

Main Research fields• 1. Spectroscopic research for bright sta

rs• 2. Stellar Asterosismology• 3. Extra-solar planets • 4. Doppler imaging• 5. Spectral line profile• 6. Chemical contents of stars• 7. Metal poor stars

Thank you