C. Executive Summary

Phil HinzPrincipal Investigator

Overall Compliance and Readiness

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0. The ORR performance requirements [12 zodi, 0.4 mJy, and 35 in-guide stars] are sufficient to meet the PLRA science objectives [inform future mission design and sensitivity >10 higher than state of the art]

Green

1.a LBTI demonstrates 12-zodi sensitivity (1, single star measurement, PLRA zodi model)Green

1.b In-guide plan (available nights) and assumptions (efficiencies and current capability) for SVP and HOSTS are documented and the science scope (<2 zodi uncertainty on median) are all consistent

Green

1.c Credible plans* documented to meet PLRA threshold performance requirements (6 zodi,0.3 mJy) by end of science validation phase with risk that is medium or lower Green

2. LBTI science data management planning and procedures meet all PLRA requirementsGreen

3. The necessary interferometer operations plans and procedures are complete, documented and in place, and under configuration management Green

4. The necessary pipeline processing algorithms, plans and procedures are complete, documented and in place, and under configuration management Green

5. The necessary staffing is in place and training has taken placeGreen

6. Project risks are documented and acceptable Green

7. During SVP, UA is ready to assume responsibility for LBTI operations and data delivery; and NExScI is ready to assume responsibility for archive Green

Overall ORR Compliance

• This presentation discusses the overall case for LBTI being ready to begin the HOSTS survey

• Relationship to ORR Success Criteria: Describes how the LBTI project satisfies the ORR performance requirements (item 1)

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1.a LBTI demonstrates 12-zodi sensitivity (1, single star measurement, PLRA zodi model)Green

1.b In-guide plan (available nights) and assumptions (efficiencies and current capability) for SVP and HOSTS are documented and the science scope (<2 zodi uncertainty on median) are all consistent

Green

1.c Credible plans* documented to meet PLRA threshold performance requirements (6 zodi, 0.3 mJy) by end of science validation phase with risk that is medium or lower Green

LBTI Mission Success Criteria

• Provide measurements of exozodi levels around nearby main sequence stars with sensitivity at least an order of magnitude higher than the current state of the art

• Provide measurements necessary to inform the design of a future NASA space mission to directly image and characterize exo-Earths around nearby main sequence stars.

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Observational Flow

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Calib

rate

d N

ull

0

n = 0.6 0.05%

LBTI fringe pattern (baseline, λ, HA)

z = 90 8 zodi

Zodi model(MIR brightness)

*

What Is 12-Zodi Sensitivity?

• The PLRA defines the sensitivity with respect to a solar twin at 10 pc– 1 zodi = 50 ppm at 11.1 µm wavelength

(luminosity-dependent)– Transmission of dust for LBTI baseline is 65% for this setup

– A solar twin at 10 pc is 2 Jy

Typical numbers used: 12 zodi = 400 ppm = 0.8 mJy

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“Sensitivity >10 State of the Art”

• Performance is currently 10–12 improved over KIN• Nulling self-calibration provides much of this improvement

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KIN (140 zodi, 1)

Threshold (6 zodi, 1)LBTI ORR (12 zodi)

Adapted from Roberge et al. 2012

Comparing KIN and LBTI Limits

KIN (8.5 µm) LBTI (11.1 µm)R1 Null uncertainty (ppm) 2000 400R2 1-zodi flux (ppm) 29 50R3 Interf. transmission 0.5 0.65

Zodi Limit (R1/R2/R3) 138 12

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“Provide Measurements to InformFuture Missions”

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Commissioning tests on the star β Leo detected a disk at the level of6000 ±500 ppmThis corresponds to a disk that is90 ±8 zodi

Commissioning tests on the star Eta Crv detected a bright disk(Defrere et al. 2015)Modeling indicates dust is at <1 AU

LBTI’s ability to inform future missions will be discussed quantitatively by B. Mennesson

ORR Success Criteria

• Demonstrate 12-zodi sensitivity• In-guide plan and assumptions for HOSTS are

all consistent with the science scope• Credible plans documented to meet the

threshold requirements by the end of science validation

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“Demonstrate 12-Zodi Sensitivity”

• Commissioning tests carried out in February 2015 demonstrated the ability to achieve a null uncertainty of 400 ppm

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Data analysis supports achieving a null uncertainty of 400 ppm in 3.5 hours

Observing sequence for β Leo demonstratesuncertainty of 500 ppm on science object

“HOSTS Plan Is Consistent with Science Scope” (1/2)

C-12 Typical Zodi Measurement Uncertainty per Star (1s)

• Uses star-dependent null uncertainty, including– Null floor = 350 ppm (irreducible, 400 ppm for 7 Jy star)– Photometric null error

• Uses best 32 stars from the HOSTS target list – Mean uncertainty is 10.3 zodi

Num

ber S

tars

Obs

erve

d

“HOSTS Plan Is Consistent withScience Scope” (2/2)

• The science team has– Published the final target list

(Weinberger et al. 2015)– Published the impact of the

instrument parameters on the observational analysis(Kennedy et al. 2015)

– Analyzed the impact of the survey on mission planning constraints (Mennesson, internal; also in Weinberger et al.)

• The Science Operations Plan details how the HOSTS survey will be carried out

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“Credible Plans to Meet Threshold” (1/2)

• During LBTI commissioning over the past year we have– Demonstrated routine AO operation with both apertures– Implemented phase stabilization– Reduced vibration inputs by nearly 3– Demonstrated accelerometer feed-forward improvements– Integrated auxiliary telemetry to improve the null stability– Demonstrated data acquisition suitable for nulling self-

calibrationThese implementations are sufficiently new that we can expect to continue to improve the performance of the system as we become more familiar with it

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“Credible Plans to Meet Threshold” (2/2)

• Specific tasks planned focus on four areas:– PWV mitigation– Vibration mitigation– Improved data acquisition

approaches– Improved photometric

sensitivity

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Compliance Matrix

PLRA Section

SuccessCriteria

March 2014

Now (ORR)

End of SVP

In-Guide Plan (FY17)

With Lien (FY18)

L0 4.3 A: 10 better 2.8 better 12 better 24 better 24 better 24 better

L0 4.3 B: Inform missions 6 zodi median

1.13 zodi median

0.51 zodi median

0.51 zodi median

0.50 zodi median

L1 4.1.2 C: 6 zodi, 1σ 54 zodi 12 zodi 6 zodi 6 zodi 6 zodi

L1 4.1.4 D: 50 stars in 4 yrs 1 3 18 35 50

L2 4.1.4 E: 0.3 mJy sens. 0.4 mJy 0.4 mJy 0.3 mJy 0.3 mJy 0.3 mJy

L2 4.1.4 F: 1.510-4 null stb 1800 ppm 400 ppm 150 ppm 150 ppm 150 ppm

L2 4.1.4 G: 30% efficiency 30% 32% 40% 40% 40%

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Red = not compliantBlue = compliant, assuming in-guide completionOrange = compliant with ORR criteria, but not PLRAGreen = compliant with PLRA