Observing Very Young Stars with GPI

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Observing Very Young Stars with GPI

• Quinn Konopacky, Bruce Macintosh, Marshall
  Perrin,
• Jenny Patience,
• et al.

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Stars younger than the primary GPI sample (lt10
Myr) represent an interesting population for
planet detection with GPI.

• Star forming regions gt 100 pc away -
  non-ideal GPI targets
• Scientific payoff of planet detection great
• Would reveal planets early in evolution
• Allow for potential comparisons to models of
  planet formation at interesting ages

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The brightest stars in young star forming regions
are potentially accessible with GPI.

• Will not represent statistically complete sample,
  but physical properties of young planets
  interesting individually
• Age spreads of young clusters often smaller than
  typical GPI target
• Might expect bright, young stars to be analogous
  to systems like HR 8799 and Fomalhaut

2MASS image of young (2 Myr) A5 star R Coronae
Australis
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Using various catalogs, a plausible target list
was generated.

• Requirement that I lt 11
• Initial list culled from Herbig Bell (1988)
  catalog
• Supplemented with more recent catalogs
  identifying additional members of southern star
  forming regions

R Coronae Australis Region
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Over 100 targets identified in 7 regions.

• Average distance 150 pc
• I-band magnitudes between 7 and 11
• Interesting regions of separation space are
  probable
• 50 known binary fraction in sample

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Over 100 targets identified in 7 regions.

• Average distance 150 pc
• I-band magnitudes between 7 and 11
• Interesting regions of separation space are
  probable
• 50 known binary fraction in sample

Fomalhaut b
HR 8799b
Neptune
HR 8799d
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Sample sources have a range of properties.

• Both cTTS and wTTS
• Range of spectral types
• Bump at K-type likely due to unresolved binarity
  or misidentification
• Some transition disk candidates

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Contrast curves and the GPI DST are used to
determine what mass of planets are detectable.
Fomalhaut b
HR 8799bc

• For I lt 9 magnitude cases, hot start models
• For star like R Cr Aus (d 130 pc), possible to
  detect planets as small as 1 MJ assuming
• All undetectable with cold start model

I 9 Distance 130 pc Age 3 Myr
Hot Start Models, Fortney et al. 2008
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Example of I9.0 source with DST shows relative
ease of detection of HR 8799b-like object.

• Used properties of R Cr Aus Star with I9, H7.1,
  Spectral Type F5
• Possibly visible in individual 30 second exposure

Single 30 second exposure
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For I11, magnitude cutoff approximated with DST.

• Same level of SNR on companion source 1-2 mags
  brighter than I9 case
• Mass limit assuming hot start 2-3 MJup for these
  fainter guide stars

Single 30 second exposure
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Other interesting science can be addressed with
this sample.

• Young stellar disks
• Can investigate transition disk phenomenon

Espaillat et al. 2007
Simulated observation of Herbig Ae star HD
141569, courtesy of Marshall Perrin
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Other interesting science can be addressed with
this sample.

• Large mass ratio binaries
• Essentially unprobed by multiplicity surveys
• Discovery can constrain star formation scenarios
  and brown dwarf formation scenarios

Bate 2009
Hinkley et al. 2010
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Summary and Possible Proposal Thoughts

• Sufficient very young (age lt 10 Myr) are
  observable with GPI to make for interesting
  sample
• Proposal should be separate from main campaign
• Combine with 5-20 Myr sample for more targets?
• Thoughts/suggestions welcomed!

Chamaeleon I Complex European Southern
Observatory/VLT UT1FORS1