Observing Very Young Stars with GPI Quinn Konopacky, Bruce Macintosh, Marshall Perrin, Jenny Patience, et al.

Stars younger than the primary GPI sample (<10 Myr) represent an interesting population for planet detection with GPI. Star forming regions > 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

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

Using various catalogs, a plausible target list was generated. Requirement that I < 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

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

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

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

Contrast curves and the GPI DST are used to determine what mass of planets are detectable. HR 8799b+c Fomalhaut b For I < 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

Example of I=9.0 source with DST shows relative ease of detection of HR 8799b-like object. Used properties of R Cr Aus Star with I~9, H~7.1, Spectral Type = F5 Possibly visible in individual 30 second exposure Single 30 second exposure

For I~11, magnitude cutoff approximated with DST. Same level of SNR on companion source ~1-2 mags brighter than I=9 case Mass limit assuming hot start ~2-3 MJup for these fainter guide stars Single 30 second exposure

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

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

Summary and Possible Proposal Thoughts Sufficient very young (age < 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 UT1+FORS1