2.4m Telescope Group

Yunnan Observatory of CAS

Status of LiJET Project &

The Coude Echelle Spectrograph for the Lijang 1.8m Telescope

China-Japan Collaboration Project Meeting @Xinglong

Chang, Liang 常 亮

Yunnan Astronomical Observatory

雲南天文台

changliang@ynao.ac.cn

2.4m Telescope Group

Yunnan Observatory of CAS

1. LiJiang Extremely High Precision ExtraSolar Planet Tracker

1 ） LIJET Project collaborators: China: USTC, YNAO, NJU USA: UFL Supported by Chinese Academy of Science and National Science Foundation of China, University

of Florida, and National Science Foundation of USA and also participating institutions including YNAO, USTC, and NJU.

2 ） Our Design Goals:* Use low-cost, compact, robust, low maintenance, but high precision and throughput Doppler instruments

* Target bright F,G,K dwarfs (V<8) with slow rotation for detection of super Earth mass planets, including habitable ones

* Integrate at least 15 min to minimize RV noises from stellar oscillations for low mass planet detection

2.4m Telescope Group

Yunnan Observatory of CAS

* A nearly perfect match of ~15 min exposure time requirements and photon noise limit offered by a 2 meter telescope for 0.5-1 m/s

• For astro-seismology, only target V<5 stars and ~1 min exposures

* Target faint solar type stars up to V~12 for moderate-high Doppler precision measurements

• Offer continuous high precision radial velocity measurements for V<8 F,G,K stars with 0.5-1 m/s Doppler precision in 30 min or less

• Follow up planet candidates from SDSS-III MARVELS planet survey

• Observe other science targets provided by the consortium members

* Network resources will be available to the entire consortium members

2.4m Telescope Group

Yunnan Observatory of CAS

3 ） . Summary of optical characteristics

Telescope Lijiang 2.4m, F/8

Fiber Input Focal Ratio F/4

Fiber Output Focal Ratio F/4

Slit Size 72um

Main disperser R2 Echelle, 63deg blaze, 87 l/mm

Cross disperser PBM2Y prism, 45 deg apex angle

Collimated beam size 85mm

Detector 4096 x 4096 CCD, 15 micron pixels

Spectra Range RVM: 390nm-690nm; DEM: 390nm-1000nm

Spectra Resolution RVM: R=18000, DEM: R=27000

Fiber core diameter RVM: 105um; DEM: 50um

2.4m Telescope Group

Yunnan Observatory of CAS

5

LiJET inside

LiJET setup in the UF lab

2.4m Telescope Group

Yunnan Observatory of CAS

LIJET telescope interface including a fiber feeding system, a fiber tip guiding and a calibration fiber light source. The calibration light was fed from the calibration lamps on the calibration bench inside the instrument control chassis

2.4m Telescope Group

Yunnan Observatory of CAS

4 ) LiJET Status

☺ LiJET already be packed in UF, will ship to China for commissioning in December or Next January （ It depends on China Customs ）☺ LiJET RMS RV errors are close to the required values, <1.5m/s for bright calibration sources in UF lab now.☺ We already built a instrument room for LiJET in 2.4m telescope basement. It’s a temperature and humidity stable room, temperature design goal is ±0.5 ,it have reached ±0.2 precision in 3 mo℃ ℃nths. And humidity is controlled in 40%-60%.☺ We have prepared all tools and spare parts for LiJET set up for commissioning.

2.4m Telescope Group

Yunnan Observatory of CAS

***Commissioning Plan, Instrument Testing and Early Science***

☺ ~6 months of commissioning (weather and instrument unpredicted nature and past EXPERT experience), one run/month, ~15 nights/run;

☺ First run with three weeks, 1st week, hardware installation, 2nd week integration with the telescope, 3rd week trial observations;

☺ Results to meet proposal requirements;

☺ Short (<14 days) and long term (~1 yr) RMS precision;

☺ Commissioning targets (≥2 RV stable starts, ≥2 RV known planets (one with short period and one with > 1 month period);

☺ Early Science: No promise of any science results, but demonstrate its science capability;

☺ Commissioning science targets: In Aug. 12th, 2010, the LiJET Project Collaborators discussed detailed commissioning science targets at Hefei City; It includes ~1 m/s science, ~3‐5 m/s science within 6 months and other science targets and plan.

2.4m Telescope Group

Yunnan Observatory of CAS

2. The Coude Echelle Spectrograph for the Lijang 1.8mTelescope

1)1.8m Telescope optical System

•Cassegrain system

•Primary Mirror: Paraboloid, Clear Aperture:1760mm Focal Ratio: F/1.5

•Two Secondary Mirrors: Hyperboloid

•Coude Focus : F/# = 89

•Nesmyth Focus: F/# = 12

•FOV: Nasmyth:18’×18’, Coude:±1.5’

2.4m Telescope Group

Yunnan Observatory of CAS

Alt-Azimuth Mounting

The Mass:25000kg

The Hight ： 7.2m

2.4m Telescope Group

Yunnan Observatory of CAS

2.4m Telescope Group

Yunnan Observatory of CAS

2.4m Telescope Group

Yunnan Observatory of CAS

2 ） 1.8m Telescope Reducer Design

Design Description ： * From F/89 to F/45

* FOV: 3’

* Spectra Range:330nm-1100nm

Blue Region: 331.17nm-577.42nm, Central wavelength 402.13nm

Red Region 562.98nm-1103.39nm, Central wavelength 703.73nm

Clear Aperture: 149.03 mm

2.4m Telescope Group

Yunnan Observatory of CAS

2.4m Telescope Group

Yunnan Observatory of CAS

Telescope Lijiang 1.8m, F/89 Lijiang 1.8m, F/89

Input Focal Ratio F/45 F/45

Main disperser R2 echelle grating

79 gr/mm

R2 echelle grating

31/.6 gr/mm

Cross disperser 60 degree UBK7 prism. 60 degree ZF3 prism.

Spectra Range 330-580nm 580-1100nm

Spectra Resolution 8200

37000

170000

12000

44000

170000

WHEN ?????

2.4m Telescope Group

Yunnan Observatory of CAS

THE END

THANKS