Transcript Progress of LiJET and Transit Search with Lijiang 2.4m Telescope

Progress of LiJET and transit search
with Lijiang 2.4m telescope
Jinming Bai (白金明)
[email protected]
Yunnan Observatory
2009-10-7
LiJET: Lijiang Exoplanet Tracker
using Doppler dispersed fix-delay
interferometer technique
by:
Florida University (Jian Ge’ group), USA
Yunnan Observatory, CAS, China
Nanjing University, China
at: the 2.4m telescope in Lijiang
The LiJET Project
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In late 2006, got supports from China and USA (1:1):
NFSC, NSF, W.M. Keck Foundation, UCF-UF SRI
program and UF
In 2007, hardware and software design started, 4
young engineers from YNAO and USTC went to
Florida University joining Jian Ge’s group
In 2008, design finished, start producing
Major Tasks and Schedule
Schematic Layout for an ET Instrument
Fringes
Telescope
Fibers
HET
Fiber
Iodine Cell
Dispersed Fringes
Medium resolution spectrograph
R=5000-10,000
Detector
Erskine & Ge (2000), Ge et al. (2002), Ge (2002)
Optical Design of RV Mode
Prism
4kx4k CCD
Slit
Collimator-camera
Output 1
Output 2
Fiber input
Monolithic Interferometer
Spectral resolution R~18,000 in 0.39-0.70 m
Echelle
Final Mechanical Layout of LiJET
4kx4k CCD
camera
Input fiber
feed
Prism
Interferometer
Collimator/camera
Echelle
A Monolithic Interferometer for LiJET
Assembled interferometer
•Field and thermal compensation
•RV thermal drift ~ 0.5m/s/mK
LiJET inside an Airtight Chamber in a Thermal Enclosure
Thermal
enclosure
Vacuum
chamber
Air legs
• The thermal enclosure dimension: 69" x 45" x 39.9“
• Thermal stability, ~1 mK over a short time and ~3mK over a long time
Echelle spectrograph
Assembled
instrument
in UF lab
Vacuum Chamber
Prism
Collimator
Thermal enclosure
The LiJET Room in the dome of 2.4m
Pipeline and Analysis Software
Modifying existing
developing
FRANCIS
FRinge Analysis Code for Interferometric Spectroscopy
Statistical analysis
Package
Optimal scheduling
Markov Chain Monte
Calo (MCMC )
long-term velocity
drifting correction
Star parameter
extraction
LiJET Design Parameters
Name
RV Mode
Fiber core diameter
Fiber input focal ratio
Image size on sky (arcsec)
Fiber output focal ratio
Collimator beam diameter
Camera focal ratio
Wavelength coverage
Main disperser
Cross-disperser
Resolution elements
Spectral resolution
CCD detector
72 m
f/4
1.55
f/4
80 mm
f/4
390-700 nm
87 l/mm R2 echelle
45 degree PBM2Y prism
4.8 pixels
18,000
4kx4k with 15 m pixels
LiJET design throughput
Telescope
81%(primary and secondary)
Fiber feed
60%
Interferometer
66%(double output including
lenses and folders)
Slit
95%
Collimator
94% (4 lenses and 6 surfaces)
Echelle efficiency
75%
Camera
85% (8 lenses, 14 surfaces)
Total throughput
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
RV precision for different type stars and
with different rotation velocity
Peng, Fleming et al. 2009
Transiting planet candidates follow-up
with LiJET
 Candidates are from:
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MARVELS (Multi-object APO Radial-Velocity Exoplanet
Large-area Survey)
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SuperWASP (Super Wide Angle Search for Planets)
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YFOSC and Mosaic CCD camera transits search in open clusters at
2.4m telescope
 Main aim:
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To confirm planet detection and discover new planets
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To detect low mass (a few Earth masses) exoplanets around nearby
planet-hosting bright stars with V<8
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To find systems with more than one giant planets
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To determine planet parameters for planet candidates being
‘significantly’ detected in the MARVELS but not well determined orbit
parameter
Detect super-earth planets around bright stars
constraining planet
formation theory
habitable planet search
LiJET sensitivity for V<8 stars
Signature of ice line and type
I migration
Schilaufman Ida & Lin 2009
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
Summary
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The designed precision of LiJET is sub m/s，
can discover earth-like planets and multiplanet system of bright stars
Planet Candidates of LiJET are from
MARVELS and SuperWASP to
determine the orbit parameters of planets
 search multi-planet systems
 earth-like planets in late type stars
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Thank You!