Robo-AO

First Science Workshop

May 20, 2010

The Demo PeriodR

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Robo-AO: Demo Period

Nicholas Law

The Demo Period

• 4 weeks on the Palomar 60”

• Q2 2011

• Mission: do lots of great science

What’s unique to Robo-AO?

• Large surveys

• High efficiency

• Continual availability

• Great sky coverage

• Visible-light & high speed imaging

Demo Period Goals

• Variety of science programs

• Extragalactic

• Transients

• Stars

• Planets

• ...

• Cover all Robo-AO unique capabilities

• Large surveys

• High efficiency

• Visible-light AO

• High NIR Strehl

• Resulting in great science... and a large group of papers

Survey Programs

Binarity survey

•all spectral types, companions down to brown dwarfs for most

•cover range of stellar parameter space with one instrument and one coherent survey

Monitoring

Trent Dupuy 2008, 2009

High availability programs

• The Palomar Transient Factory finds 1 transient candidate every ~10 minutes

• Many found near galactic nuclei - how do we separate them?

New Old Subtraction

5/17/2010 2Astronomy Tea Talk

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High-speed, high-resolution imaging

How much time is one month?

• Overheads

• 35-40 secs: telescope pointing & settling

• 20 secs: Centering on target & verification

• 10 secs: WFS calibration, wait for loop to close

• Assume:

• no science in first week

• 50% uptime

• 30% weather losses

• Conservatively ~60 hours, or 1800 targets at 2 mins per target

• However, we need about 5000 targets for contingency!

Types of demo programs

• Large, 1000 targets

• Need to be very exciting papers -- only 2-3 possible

• High-risk if incomplete

• Medium, 100-300 targets

• 10+ projects

• Lower risk

• Others

• eg. transient followup (equiv. to 4m in sensitivity...)

Demo period capabilities

• General AO imaging

• NIR & Visible [specific NIR camera TBD]

• Dithering, standard observation sequences, etc.

• Visible-light high-speed imaging

• Efficiency will improve throughout run

• Likely semi-robotic system

• Probably manual target lists to start with

• Maybe some simple scheduling by end of demo

Decision process

• Projects defined by September

• Robo-AO team will collaborate, provide data, and support for data reduction, in exchange for paper authorship

• Mini-TAC process within Robo-AO team

• Current science team:

• C. Baranec, R. Dekany, J. Johnson, M. Kasliwal, M. van Kerkwijk, S. Kulkarni, N. Law, T. Morton, E. Ofek, A. Ramaprakash, R. Riddle, S. Tendulkar

Robo-AO Robo-AO Astrometry (1)Astrometry (1)

Nicholas LawNicholas Law

Astrometric Performance Astrometric Performance LimitsLimits

Signal, noise, and image size (photon statistics):Signal, noise, and image size (photon statistics):

SystematicsSystematics

Focal plane distortionFocal plane distortion

Atmospheric refraction (inc. chromatic Atmospheric refraction (inc. chromatic effects)effects)

Changes in instrument / telescopeChanges in instrument / telescope

Atmospheric turbulenceAtmospheric turbulence

Astrometric Performance Astrometric Performance LimitsLimits

Focal plane distortionFocal plane distortion

Atmospheric refraction (inc. chromatic Atmospheric refraction (inc. chromatic effects)effects)

Changes in instrument / telescopeChanges in instrument / telescope

Atmospheric turbulenceAtmospheric turbulence

Detailed calibration using crowded fieldsDetailed calibration using crowded fields

Work in narrow bands in the near-IR: Work in narrow bands in the near-IR:

in a 30nm bandpass at 2.0in a 30nm bandpass at 2.0μμm refraction effects are < m refraction effects are < 5050μμasas

• Don’t do that! Robo-AO won’tDon’t do that! Robo-AO won’t

Complicated... but that’s what Robo-AO is forComplicated... but that’s what Robo-AO is for

Band SNR Compared to 1.5 m

SNR Compared to 4 m

FWHM (1” is typical)

Strehl

J 2.9X 0.4X 0.2” 50%

H 7.1X 0.98X 0.26” 70%

Robo-AO AstrometryRobo-AO Astrometry

Astrometric precision gains in FWHM & SNRAstrometric precision gains in FWHM & SNR

With careful experimental design, performance With careful experimental design, performance limited by atmospheric tip/tilt jitter (see Cameron limited by atmospheric tip/tilt jitter (see Cameron et al. 2009)et al. 2009)

Prediction of performance:Prediction of performance:

100-200uas precision in 10-30 minutes100-200uas precision in 10-30 minutes(depending on details of target & field)(depending on details of target & field)

Integration time / secondsIntegration time / seconds

2 milliarcsec2 milliarcsec

M-dwarf Planetary M-dwarf Planetary PopulationsPopulations

Only 16 planetary systems detected around M-dwarfs (<~0.6 solar Only 16 planetary systems detected around M-dwarfs (<~0.6 solar masses)masses)

Several hundred detected around solar-type starsSeveral hundred detected around solar-type stars

M-dwarfs are very M-dwarfs are very FAINT and red FAINT and red for RV searchesfor RV searches

Only the highest-mass M-dwarfs (<M3) have been probed with Only the highest-mass M-dwarfs (<M3) have been probed with radial velocity searchesradial velocity searches

Even so, some of the most interesting systems have been found Even so, some of the most interesting systems have been found around M-dwarfsaround M-dwarfs

Gl 581Gl 581

2 M2 MEarthEarth

16 M16 MEarthEarth

5 M5 MEarthEarth

7 M7 MEarthEarth

Mayor et al 2009 arXiv:0906.2780

MM-dwarf -dwarf AAstrometric strometric AOAO PPlanet lanet SSurveyurvey

Target M-dwarfs in galactic planeTarget M-dwarfs in galactic plane

Few hundred microarcsec precision per epochFew hundred microarcsec precision per epoch

Sensitive to Jupiter-mass planets in few-month Sensitive to Jupiter-mass planets in few-month orbitsorbits

Competitive with (future) ~10 m/s radial velocity Competitive with (future) ~10 m/s radial velocity surveys around mid M-dwarfs for few month orbitssurveys around mid M-dwarfs for few month orbits

Robo-AO: Binarity Survey

Nicholas Law

Multiplicity in solar neighborhood

5/17/2010 2Astronomy Tea Talk

• Various surveys

• Solar type stars:

• Duquennoy & Mayor (1991)

• More recent RV surveys

• Some AO BD surveys (eg. Gelino et al.)

• All 100-200 targets

• M-dwarfs

• Lots of ~50-target AO surveys

• RV surveys starting up for planet searches

• Other types have a similar patchwork of surveys

Robo-AO’s contribution

5/17/2010 2Astronomy Tea Talk

• 8 Target groups

• A, F, G, K, M0-3, M3-6, M6-9, L0+

• Sensitivity

• High-mass BD companions in ~120 secs (at large radii)

• Main sequence companions at most separations

• In visible, white dwarf companions reachable

• CPM confirmation in 1 month is conceivable

• Target numbers

• 150 targets per night

• Useful contribution in 5-8 nights @ 150 targets per target group

• Large, coherent, well-understood-bias survey