We present a statistical analysis of the first 300 stars observed by the Gemini Planet Imager Exoplanet Survey. This subsample includes six detected planets and three brown dwarfs; from these detections and our contrast curves we infer the underlying distributions of substellar companions with respect to their mass, semimajor axis, and host

2 Wang et al. The HR 8799 system uniquely harbors four young super-Jupiters whose orbits can provide insights into the system's dynamical history and constrain the masses of the planets themselves. Using the Gemini Planet Imager (GPI), we obtained down to one milliarcsecond precision on the astrometry of these planets. We assessed four-planet orbit models with different levels of constraints and found that assuming the planets are near 1:2:4:8 period commensurabilities, or are coplanar, does not worsen the fit. We added the prior that the planets must have been stable for the age of the system (40 Myr) by running orbit configurations from our posteriors through N -body simulations and varying the masses of the planets. We found that only assuming the planets are both coplanar and near 1:2:4:8 period commensurabilities produces dynamically stable orbits in large quantities. Our posterior of stable coplanar orbits tightly constrains the planets' orbits, and we discuss implications for the outermost planet b shaping the debris disk. A four-planet resonance lock is not necessary for stability up to now. However, planet pairs d and e, and c and d, are each likely locked in two-body resonances for stability if their component masses are above 6 M Jup and 7 M Jup , respectively. Combining the dynamical and luminosity constraints on the masses using hot-start evolutionary models and a system age of 42 ± 5 Myr, we found the mass of planet b to be 5.8 ± 0.5 M Jup , and the masses of planets c, d, and e to be 7.2 +0.6 −0.7 M Jup each.

Citation for published item:uonopkyD uinn wF nd meuD tulien nd huh¢ eneD qsprd nd pilippzzoD toseph gF nd qiorl qodfreyD ige eF nd wroisD ghristin nd xielsenD iri vF nd ueyoD vurent nd (kovD omn F nd ieD imily vF nd ngD tson tF nd emmonsD F wrk nd fileyD ness F nd frmnD rvis F nd fulgerD tonn nd fruzzoneD estin nd ghiloteD te'rey uF nd gottenD r nd hwsonD eekh sF nd he osD oert tF nd hoyonD en¡ e nd ispositoD homs wF nd pitzgerldD wihel F nd polletteD utherine fF nd qoodsellD tephen nd qrhmD tmes F nd qreenumD elexndr F nd rionD sle nd rungD viEei nd sngrhmD trik nd ulsD ul nd vfreni ereD hvid nd vrkinD tmes iF nd wintoshD frue eF nd wireD t¡ er¢ ome nd wrhisD prnk nd wrleyD wrk F nd wtthewsD frend gF nd wethevD tnimir nd willrEflnherD wxwell eF nd yppenheimerD ee nd lmerD hvid F nd tieneD tenny nd errinD wrshll hF nd oyneerD vis eF nd jnD ehijith nd ntkyr¤ oD predrik F nd vrnskyD hmitry nd hneiderD edm gF nd ivrmkrishnnD ennd nd ongD snseok nd oummerD emi nd homsD ndrine nd lleD tF uent nd rdEhuongD uimerly nd iktorowizD lone tF nd ol'D huyler qF @PHITA 9hisovery of sustellr ompnion to the nery deris disk host r PSTPF9D estrophysil journl lettersFD VPW @IAF vRF Further information on publisher's website: Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. ABSTRACTWe present the discovery of a brown dwarf companion to the debris disk host star HR 2562. This object, discovered with the Gemini Planet Imager (GPI), has a projected separation of 20.3±0.3 au (    0. 618 0. 004) from the star. With the high astrometric precision afforded by GPI, we have confirmed, to more than 5σ, the common proper motion of HR 2562B with the star, with only a month-long time baseline between observations. Spectral data in the J-, H-, and K-bands show a morphological similarity to L/T transition objects. We assign a spectral type of L7±3 to HR 2562Band derive a luminosity of log(, corresponding to a mass of 30±15 M Jup from evolutionary models at an estimated age of the system of 300-900 Myr. Although the uncertainty in the age of the host star is significant, the spectra and photometry exhibit several indications of youth for HR 2562B. The source has a position angle that is consistent with an orbit in the same plane as the debris disk recently resolved with Herschel. Additionally, it appears to be interior to the debris disk. Though the extent of the inner hole is currently too uncertain to place limits on the mass of HR 2562B, future observations of the disk with higher spatial resolution may be able to provide m...

We present L'-band imaging of the PDS 70 planetary system with Keck/NIRC2 using the new infrared pyramid wave front sensor. We detected both PDS 70 b and c in our images, as well as the front rim of the circumstellar disk. After subtracting off a model of the disk, we measured the astrometry and photometry of both planets. Placing priors based on the dynamics of the system, we estimated PDS 70 b to have a semimajor axis of-+ 20 4 3 au and PDS 70 c to have a semimajor axis of-+ 34 6 12 au (95% credible interval). We fit the spectral energy distribution (SED) of both planets. For PDS 70 b, we were able to place better constraints on the red half of its SED than previous studies and inferred the radius of the photosphere to be 2-3R Jup. The SED of PDS 70 c is less well constrained, with a range of total luminosities spanning an order of magnitude. With our inferred radii and luminosities, we used evolutionary models of accreting protoplanets to derive a mass of PDS 70 b between 2 and 4 M Jup and a mean mass accretion rate between 3×10 −7 and 8×10 −7 M Jup /yr. For PDS 70 c, we computed a mass between 1 and 3 M Jup and mean mass accretion rate between 1×10 −7 and 5×10 −7 M Jup /yr. The mass accretion rates imply dust accretion timescales short enough to hide strong molecular absorption features in both planets' SEDs. Unified Astronomy Thesaurus concepts: Exoplanet formation (492); Exoplanet atmospheres (487); Orbit determination (1175); Exoplanet dynamics (490); Coronagraphic imaging (313);