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Directly imaged substellar companions with well-constrained ages and masses serve as vital empirical benchmarks for planet formation and evolution models. Potential benchmark companions can be identified from astrometric accelerations of their host stars. We use Gaia DR3 and Hipparcos astrometry to identify 166 northern hemisphere stars with astrometric accelerations consistent with a substellar companion between 0 .″ 5 and 1″. For this accelerating sample we identify young stars using Apache Point Observatory/ARCES spectra and TESS light curves. From spectroscopic screening of the sample, we measure ages for 24 stars with detectable amounts of lithium, place lower age limits on 135 stars with lithium nondetections, and measure ages from RHK′ for 34 stars. A total of 129 stars have TESS light curves, from which we measure ages for 20 stars with rotation rates <15 days, and we identify three eclipsing binaries. We present median ages and confidence intervals of age posteriors for the entire sample and discuss how the overall age distribution of our sample compares to a uniform star formation rate in the solar neighborhood. We identify 47 stars with median ages <2 Gyr, 31 stars with median ages <1 Gyr, and 14 stars with median ages <0.5 Gyr, making them high-priority targets for direct imaging follow-up.

Walter M.Miller, Jr., was one of the twentieth century's leading science fiction writers, a two-time Hugo Award winner and author of the classic novels A Canticle for Leibowitz and Saint Leibowitz and the Wild Horse Woman.This comprehensive literary guide provides more than 1,500 alphabetically arranged entries on Miller's life and body of work.

This book is written for anyone who has been inspired by the idea of Team-Based Learning (TBL) through his or her reading, a workshop, or a colleague's enthusiasm, and then asks the inevitable question: how do I start?Written by five authors who use TBL in their teaching and who are internationally recognized as mentors and trainers of faculty making the switch to TBL, the book also presents the tips and insights of 46 faculty members from around the world who have adopted this teaching method.TBL is a uniquely powerful form of small group learning. It harnesses the power of teams and social learning with accountability structures and instructional sequences. This book provides the guidance, from first principles to examples of practice, together with concrete advice, suggestions, and tips to help you succeed in the TBL classroom. This book will help you understand what TBL is and why it is so powerful. You will find what you need to plan, build, implement, and use TBL effectively. This book will appeal to both the novice and the expert TBL teacher.

We present new spatially resolved astrometry and photometry of the CD –27°11535 system, a member of the β Pictoris moving group consisting of two resolved K-type stars on a ∼20 yr orbit. We fit an orbit to relative astrometry measured from NIRC2, GPI, and archival NaCo images, in addition to literature measurements. However, the total mass inferred from this orbit is significantly discrepant from that inferred from stellar evolutionary models using the luminosity of the two stars. We explore two hypotheses that could explain this discrepant mass sum: a discrepant parallax measurement from Gaia due to variability, and the presence of an additional unresolved companion to one of the two components. We find that the ∼20 yr orbit could not bias the parallax measurement, but that variability of the components could produce a large-amplitude astrometric motion, an effect that cannot be quantified exactly without the individual Gaia measurements. The discrepancy could also be explained by an additional star in the system. We jointly fit the astrometric and photometric measurements of the system to test different binary and triple architectures for the system. Depending on the set of evolutionary models used, we find an improved goodness of fit for a triple system architecture that includes a low-mass (M = 0.177 ± 0.055 M ⊙) companion to the primary star. Further studies of this system will be required in order to resolve this discrepancy, either by refining the parallax measurement with a more complex treatment of variability-induced astrometric motion or by detecting a third companion.

HD 143811 AB is the host star to the directly imaged planet HD 143811 AB b, which was recently discovered using data from the Gemini Planet Imager and Keck NIRC2. A member of the Sco-Cen star-forming region with an age of 13 ± 4 Myr, HD 143811 AB is somewhat rare among hosts of directly imaged planets, as it is a close stellar binary, with an ∼18-day period. Accurate values for the orbital and stellar parameters of this binary are needed to understand the formation and evolutionary history of the planet in orbit. We utilize archival high-resolution spectroscopy from FEROS on the MPG/ESO 2.2 m telescope to fit the orbit of the binary, and we combine with unresolved photometry to derive the basic stellar properties of the system. From the orbit, we derive precise values of orbital period of 18.59090 ± 0.00007 days and mass ratio of 0.886 ± 0.003. When combined with stellar evolutionary models, we find masses of both components of MA=1.30−0.05+0.03 M⊙ and MB=1.15−0.04+0.03 M⊙. While the current data are consistent with the planet and stellar orbits being coplanar, the 3D orientations of both systems are currently poorly constrained, with additional observations required to more rigorously test for coplanarity.

We present confirmation of HD 143811 AB b, a substellar companion to spectroscopic binary HD 143811 AB through direct imaging with the Gemini Planet Imager (GPI) and Keck NIRC2. HD 143811 AB was observed as a part of the GPI Exoplanet Survey in 2016 and 2019 and is a member of the Sco-Cen star formation region. The exoplanet is detected ∼430 mas from the host star by GPI. With two GPI epochs and one from Keck/NIRC2 in 2022, we confirm through common proper motion analysis that the object is bound to its host star. We derive an orbit with a semimajor axis of 64−14+32 au and eccentricity 0.23−0.16+0.24 . Spectral analysis of the GPI H-band spectrum and NIRC2 L′ photometry provides additional proof that this object is a substellar companion. We compare the spectrum of HD 143811 AB b to PHOENIX stellar models and Exo-Radioactive-Convective Equilibrium Model (REM) exoplanet atmosphere models and find that Exo-REM models provide the best fits to the data. From the Exo-REM models, we derive an effective temperature of 1042−132+178 K for the planet and translate the derived luminosity of the planet to a mass of 5.6 ± 1.1 MJup assuming hot-start evolutionary models. HD 143811 AB b is the first directly imaged planet around a binary that is not on an ultrawide orbit. Future characterization of this object will shed light on the formation of planets around binary star systems.

This is a study examining the interaction between certain doctoral student engagement indicators (peer, institution, curriculum, faculty, spirituality) and student satisfaction. The scope is to understand if student sense of community is a significant moderator to this interaction in order to address the issue of student attrition. It is important to understand these interactions and the influence of sense of community so that institutions of higher education better analyze student commitment. The outcomes of this study may be used as a means to design and implement engagement strategies that are effective in student retention and completion. Doctoral students were invited through email to participate in a Likert survey comprised of multiple scales measuring the key engagement indicators along with sense of community and student satisfaction. The quantitative results show that engagement is a predictor of satisfaction and, in some cases, is significantly moderated by sense of community. This study supports contemporary research conclusions suggesting that both student engagement and academic communities are paramount to student satisfaction which will ultimately lead to higher rates of retention. Recommendations for future research include determining how online students will be better served through engaging academic communities and strategies designed to enhance the engagement experiences.

(abridged) Expanding the sample of directly imaged companions to nearby, young stars that are amenable to detailed astrometric and spectroscopic studies is critical for the continued development and validation of theories of their evolution and atmospheric processes. The recent release of the ıt Gaia astrometric catalogue allows us to efficiently search for these elusive companions by targeting those stars that exhibit the astrometric reflex motion induced by an orbiting companion. The nearby (27 pc), young (24 Myr) star AF Leporis (AF Lep) was targeted because of its astrometric acceleration, consistent with a wide-orbit planetary companion detectable with high-contrast imaging. We used the SPHERE instrument on the VLT to search for faint substellar companions in the immediate vicinity of AF Lep. We used observations of a nearby star interleaved with those of AF Lep to efficiently subtract the residual point spread function. This provided sensitivity to faint planetary-mass companions within 1 arcsec (\\(\\)30 au) of the star. We detected the companion AF Lep b at a separation of 339 mas (9 au), within the inner edge of its unresolved debris disk. The measured \\(K\\)-band contrast and the age of the star yield a model-dependent mass of 4 and 6 \\(M_ Jup\\), consistent with the mass derived from an orbital fit of \\(4.3_-1.2^+2.9\\) \\(M_ Jup\\). The near-infrared SED of the planet is consistent with an object at the L--T spectral type transition, but under-luminous with respect to field-gravity objects. AF Lep b joins a growing number of substellar companions imaged around stars in the young \\(\\) Pic moving group. With a mass of between 3 and 7 \\(M_ Jup\\), it occupies a gap in this isochronal sequence between the hotter, more massive companions like PZ~Tel~B and \\(\\)~Pic~b, and the cooler 51~Eri~b, which is sufficiently cool for methane to form within its photosphere.

We present confirmation of HD 143811 AB b, a substellar companion to spectroscopic binary HD 143811 AB through direct imaging with the Gemini Planet Imager (GPI) and Keck NIRC2. HD 143811 AB was observed as a part of the Gemini Planet Imager Exoplanet Survey (GPIES) in 2016 and 2019 and is a member of the Sco-Cen star formation region. The exoplanet is detected \\( 430\\) mas from the host star by GPI. With two GPI epochs and one from Keck/NIRC2 in 2022, we confirm through common proper motion analysis that the object is bound to its host star. We derive an orbit with a semi-major axis of \\(64 ^+32_-14\\) au and eccentricity \\(0.23 ^+0.24_-0.16\\). Spectral analysis of the GPI \\(H\\)-band spectrum and NIRC2 L' photometry provides additional proof that this object is a substellar companion. We compare the spectrum of HD 143811 AB b to PHOENIX stellar models and Exo-REM exoplanet atmosphere models and find that Exo-REM models provide the best fits to the data. From the Exo-REM models, we derive an effective temperature of \\(1042^+178_-132\\) K for the planet and translate the derived luminosity of the planet to a mass of \\(5.6 1.1~M_Jup\\) assuming hot-start evolutionary models. HD 143811 AB b is the first directly imaged planet around a binary that is not on an ultra-wide orbit. Future characterization of this object will shed light on the formation of planets around binary star systems.