Progress of LiJET and transit search with Lijiang 2.4m telescope
Jinming Bai ( 白金明 )[email protected]
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!
Top Related