jian ge, university of florida

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Jian Ge, University of Florida

A Global Network for Planet Detection and Asteroseismology Study using Extremely high

Precision Extrasolar Planet Tracker Instruments

UF team members: Bo Zhao, John Groot, Liang Chang, Xiaoke Wan, Frank Varosi, Scott Powell, Kevin Hanna, Peng Jiang, Scott Fleming, Brian Lee, Rohan Pais, Ji Wang, Liming Dou, Jian Liu, Erin Costello, Adriana Delgado-Navarro, Sandeep Reddy Bollampally, Troy Bosman, Sid Schofield, Bo Ma, & Hali Jakeman

EXPERT Network International Members: T. Wang (China team leader), J.L. Zhou, W.M. Yuan, H.Y. Zhou, J.M. Bai, Y.F., Fan., S.H. Gu, & E. Martin (Spanish team leader)

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Strategy for Building a Global Doppler Network

• Take advantage of retiring 2 meter telescopes and convert them into semi-dedicated telescope network for long term surveys• Develop 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•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 asteroseismology, only target V<5 stars and ~1 min exposures

Key: new technology Doppler instruments

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USA

EXPERT, Sept. 09

Spain

SET, 11?China

LiJET, June, 10

Global Extremely High Precision Exoplanet Tracker Network

•Offer continuous high precision radial velocity measurements for V<8 FGK stars with 0.5-1 m/s Doppler precision in 30 min •Follow up planet candidates from SDSS-III MARVELS planet survey•Compact and low cost design (~$750K per instrument including hardware and labor; cost may be further reduced for smaller telescopes)

Australia ?

Hawaii ? Chile ?

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High Precision RV Mode

Fiber inputMichelson Interferometer

Prism Echelle

4kx4k CCD

Collimator-cameraSlit Output 1

Output 2

• A combination of a fixed-delay interferometer with a high throughput cross-dispersed echelle spectrograph with R=18,000 •A simultaneous wavelength coverage of 0.39-0.70 m•0.5-1 m/s in 30 min for V< 8 solar type stars with 2 m telescopes

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Fixed-delay Interferometer Doppler Principle

dm

c

ddm

2

d/2 /2

m m-1

Incoming beam

Mirror 1

Mirror 2 image

Fringe order and delay relationship:

Fringe shift caused by wavelength change:

2

d

cm

d

c

Doppler shift and phase shift relationship:

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DFDI principle

Stellar Stellar spectrumspectrum

x combx comb

ET spectrumET spectrum

Credits: Julian van Eyken

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Direct Cross-dispersed Echelle Mode

Fiber input

Prism Echelle

4kx4k CCD

Collimator-cameraSlit

• The cross-dispersed echelle spectroscopy mode with R=27,000 and a simultaneous wavelength coverage of 0.39-1.0 m

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Photon limited RV precision in 30 min exposures with EXPERT

Magnitude RV precision

V=6 0.4 m/s

V=7 0.6 m/s

V=8 1.0 m/s

Primary targets for EXPERT network

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Detection of Earth-like short period planets with 1 m/s Doppler precision

•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

•Need good orbital phase coverage to eliminate other noises

Credit: S. Kane

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Opt-mechanical layout of EXPERT

EchellePrism

Collimator/camera

4kx4k CCD camera

InterferometerInput fiber feed

•The thermal enclosure dimension: 69" x 45" x 39.9".•Temperature and pressure controlled•Goals to reach ~2mpsi, ~4 mK and <10 m/s drift over 1 week

Thermal enclosure

Pressure controlled chamber

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EXPERT hardware setup at Kitt Peak 2.1m in Sept. 2009

EXPERT inside a 2.1m Coude room

EXPERT control chassis

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EXPERT inside a Thermally Controlled Chamber at Kitt Peak in Sept. 2009

ChamberThermal enclosure

Echelle

Prism Collimator/Camera 4kx4k CCD

Interferometer

RV input fiber

DEM input fiber

Pressure sensor

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Solar Spectra on the Detector with EXPERT

Order 52, 0.39 m

Order 29, 0.70 m

Order 29, 0.70 m

Order 52, 0.39 m

Output 2

Output 1

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Early RV measurement results with EXPERT

Photon error =1.3m/s with 12

orders combined Photon error =1.2m/s with

12 orders combined

Photon error =4.7m/s

with 9 orders combined

Observations with Iodine absorption Observations with sky

Observations with 51 Peg

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Order 20, 1.0 m

Order 52, 0.39 m

Cross-dispersed echelle spectra of NSV 860 (K2 EB, V=8.7) in Jan. 10

R=27,000

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RV Drifts vs. Pressure and Temperature variation with EXPERT in Oct. 2009

•Need to control pressure and temperature to reach higher RV stability

RV vs Pressure

RV

Pressure RV vs Temperature

RV

Temperature

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EXPERT Instrument Temperature Monitoring in Dec. 2009

•Instrument temperature varies within 10 mK over 5 days

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EXPERT Instrument RV Monitoring in Mar. 2010

RV vs temperature in 4 days

50 m/s12 mk

RV vs pressure in 4 days

100 mpsi

RMS=1.4m/s with Iodine calibration

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LiJET hardware setup at the UF lab in Jan. 2010

LiJET inside a 2.1m Coude room

LiJET setup in the UF lab

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LiJET Instrument Temperature Monitoring in Mar. 2010

15 mK

3mpsi

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Exoplanet Tracker Network Plan

Future plan•Looking for more partners to complete 6 network instrument development and implementation•Raising federal, state and private funds for operating the network•Combining with up-coming space transit missions for bright stars to detect and characterize habitable rocky planets

Primary science targets•V<8 FGK main sequence stars with slow rotation and low activities for super Earth mass planet detection and characterization•Followup of MARVELS planet and brown dwarf candidates to confirm and characterize new giant planets and find additional planet companions•A few very bright solar type stars (V<5) for asteroseismology study

Science operation •Science operation with EXPERT at Kitt Peak in April 2010•Science operation with LiJET at Lijiang, China in September 2010•Complete the Spanish Exoplanet Tracker (SET) in early 2011 pending on remaining fund raising and telescope negotiation

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The Multi-object Optical Doppler instrument at SDSS in Sept 08

MARVELS Plugging Plate

MARVELS Fibers

MARVELS-I inside an air condition room

InstrumentCalibration box

Control box

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MARVELS RV drift

• RV drift is about 20 m/s over ~3 days

• Temperature change is about 5 mK over ~3days.

20 m/s

5 mK

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Discoveries of Two Brown Dwarfs by MARVELS

A new brown dwarf with 20 Jupiter masses and 5.9 day period

A new brown dwarf with 50 Jupiter masses and 5.8day period

Lee et al. 2010, ApJ submitted Fleming et al. 2010, submitted

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Planet Candidates by MARVELS

V=9.2, Teff=4866K, logg=3.5P=80.2days, Msini=1.9MJ V=11.3, Teff=5606K,

logg=3.8, P=33.5days, Msini=6.5MJ

V=8.4, P=109.4days, Msini=2.0MJ

V=9.4, Teff=5889K, logg=4.1, P=13.3days, Msini=1.0MJ

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V=8.4, P=23.8days, Msini=2.9MJ

Planet Candidates by MARVELS

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Summary

We acknowledge support from NSF, W.M. Keck Foundation, NASA, Sloan Foundation, SDSS-III program, DoD, NSFC, UCF-UF SRI, & UF

• EXPERT delivers ~14% total detection efficiency from the telescope to the detector under typical seeing condition (1.5 arcsec at the KPNO 2.1m), operating in 0.39-0.7 um•Pressure control to within 2 mpsi over ~1 wk•Temperature control to within 10mK over ~1wk, goal to reach 2-4mK•RV drift within 50 m/s over a few days, goal to reach <10m/s long term goal• Reach ~1 m/s with iodine bracketing calibration for 1 hour integration, goal to reach 0.5 m/s with the ThAr or white light interferometer comb calibration over 0.39-0.7 um•Science operation with EXPERT in April 2010, with LiJET in September 2010, and more later•EXPERT direct echelle, covering 0.39-1.0 um with R=27,000, can reach ~3 m/s for mid-late M dwarfs for a J=7 M dwarf in 10 min planet survey with M dwarfs

jian ge, university of florida

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