Progress of LiJET and transit search with Lijiang 2.4m telescope

Jinming Bai ( 白金明 )baijinming@mail.ynao.ac.cn

Yunnan Observatory

2009-10-7

LiJET:LiJET: Lijiang Exoplanet TrackerLijiang Exoplanet Trackerusingusing Doppler dispersed fix-delay interferometer technique

by:by:

Florida University (Jian Ge’ group), USAFlorida University (Jian Ge’ group), USA

Yunnan Observatory, CAS, ChinaYunnan Observatory, CAS, China

Nanjing University, ChinaNanjing University, China

at: the 2.4m telescope in Lijiangat: the 2.4m telescope in Lijiang

In late 2006, got supports from China and USA (1:1): In late 2006, got supports from China and USA (1:1): NFSC, NSF, W.M. Keck Foundation, UCF-UF SRI pNFSC, NSF, W.M. Keck Foundation, UCF-UF SRI program and UFrogram and UF

In 2007, hardware and software design started, 4 youIn 2007, hardware and software design started, 4 young engineers from YNAO and USTC went to Florida ng engineers from YNAO and USTC went to Florida University joining Jian Ge’s groupUniversity joining Jian Ge’s group

In 2008, design finished, start producingIn 2008, design finished, start producing

The LiJET ProjectThe LiJET Project

Major Tasks and Schedule

Schematic Layout for an ET Instrument

HET Fiber

Fringes

Dispersed Fringes

Iodine Cell Fibers

Telescope

Detector

Erskine & Ge (2000), Ge et al. (2002), Ge (2002)

Medium resolution spectrograph R=5000-10,000

Optical Design of RV Mode

Fiber input Monolithic Interferometer

Prism Echelle

4kx4k CCD

Collimator-cameraSlit

Output 1

Output 2

Spectral resolution R~18,000 in 0.39-0.70 m

Final Mechanical Layout of LiJET

EchellePrism

Collimator/camera

4kx4k CCD camera

InterferometerInput fiber feed

A Monolithic Interferometer for LiJET

•Field and thermal compensation•RV thermal drift ~ 0.5m/s/mK

Assembled interferometer

LiJET inside an Airtight Chamber in a Thermal Enclosure

Air legs

Thermal enclosure

Vacuum chamber

• The thermal enclosure dimension: 69" x 45" x 39.9“• Thermal stability, ~1 mK over a short time and ~3mK over a long time

Vacuum Chamber Thermal enclosure

Echelle spectrograph

Prism

CollimatorAssembled instrument in UF lab

The LiJET Room in the dome of 2.4mThe LiJET Room in the dome of 2.4m

Pipeline and Analysis Pipeline and Analysis SoftwareSoftware

FRANCIS FRinge Analysis Code for Interferometric Spectroscopy

Statistical analysis Package

Optimal scheduling

long-term velocity drifting correction

Star parameterextraction

Modifying existing

developing

Markov Chain Monte Calo (MCMC )

LiJET Design Parameters     

Name RV Mode

Fiber core diameter 72 m Fiber input focal ratio f/4 Image size on sky (arcsec) 1.55 Fiber output focal ratio f/4 Collimator beam diameter 80 mm Camera focal ratio f/4 Wavelength coverage 390-700 nm Main disperser 87 l/mm R2 echelle Cross-disperser 45 degree PBM2Y prism Resolution elements 4.8 pixels Spectral resolution 18,000 CCD detector 4kx4k with 15 m pixels

LiJET design throughputLiJET design throughput

TelescopeTelescope 81%(primary and 81%(primary and secondary) secondary)

Fiber feedFiber feed 60%60%

InterferometerInterferometer 66%(double output 66%(double output including lenses and including lenses and folders)folders)

SlitSlit 95%95%

CollimatorCollimator 94% (4 lenses and 6 94% (4 lenses and 6 surfaces)surfaces)

Echelle efficiencyEchelle efficiency 75%75%

CameraCamera 85% (8 lenses, 14 85% (8 lenses, 14 surfaces) surfaces)

Total throughputTotal throughput 18% 18%

Photon limited RV precision of 15 min exposures with LiJET at Lijiang 2.4m telescope

Magnitude RV precision

V=6 0.4 m/s

V=7 0.6 m/s

V=8 1.0 m/s

V=9 1.6 m/s

V=10 2.5 m/s

Peng, Fleming et al. 2009

RV precision for different type stars and with different rotation velocity

Transiting planet candidates follow-up with LiJET

Candidates are from: MARVELS (Multi-object APO Radial-Velocity Exoplanet

Large-area Survey) SuperWASP (Super Wide Angle Search for Planets) YFOSC and Mosaic CCD camera transits search in open clusters at 2.4

m telescope

Main aim: To confirm planet detection and discover new planets To detect low mass (a few Earth masses) exoplanets around nearby pla

net-hosting bright stars with V<8 To find systems with more than one giant planetsTo find systems with more than one giant planets To determine planet parameters for planet candidates being ‘significaTo determine planet parameters for planet candidates being ‘significa

ntly’ detected in the MARVELS but not well determined orbit parametntly’ detected in the MARVELS but not well determined orbit parameterer

Detect super-earth planets around Detect super-earth planets around bright starsbright stars

constraining planet formation theory

habitable planet search

Signature of ice line and type I migration

Schilaufman Ida & Lin 2009

LiJET sensitivity for V<8 stars

Detection of Earth-like short period planets with intensive LiJET observations

• 2 Earth mass planet, 2.2 day period around a solar type star, K= 1m/s

= 1m/s, 60 measurements, clear detection with 0.1% FAP

SummarySummary

The designed precision of LiJET is sub m/sThe designed precision of LiJET is sub m/s ，， can discover earth-like planets and multi-pcan discover earth-like planets and multi-planet system of bright starslanet system of bright stars

Planet Candidates of LiJET are from MARPlanet Candidates of LiJET are from MARVELS and VELS and SuperWASP to to determine the orbit parameters of planetsdetermine the orbit parameters of planets search multi-planet systemssearch multi-planet systems earth-like planets in late type starsearth-like planets in late type stars

Thank You!Thank You!