The HD 93963 A transiting system: A 1.04d super-Earth and a 3.65 d sub-Neptune discovered by TESS and CHEOPS

peer reviewe

Two warm Neptunes transiting HIP 9618 revealed by TESS and Cheops

peer reviewedHIP 9618 (HD 12572, TOI-1471, TIC 306263608) is a bright (G = 9.0 mag) solar analogue. TESS photometry revealed the star to have two candidate planets with radii of 3.9 ± 0.044 R (HIP 9618 b) and 3.343 ± 0.039 R (HIP 9618 c). While the 20.77291 d period of HIP 9618 b was measured unambiguously, HIP 9618 c showed only two transits separated by a 680-d gap in the time series, leaving many possibilities for the period. To solve this issue, CHEOPS performed targeted photometry of period aliases to attempt to recover the true period of planet c, and successfully determined the true period to be 52.56349 d. High-resolution spectroscopy with HARPS-N, SOPHIE, and CAFE revealed a mass of 10.0 ± 3.1M for HIP 9618 b, which, according to our interior structure models, corresponds to a 6.8 ± 1.4 per cent gas fraction. HIP 9618 c appears to have a lower mass than HIP 9618 b, with a 3-sigma upper limit of 50 d, opening the door for the atmospheric characterization of warm (Teq < 750 K) sub-Neptunes

The Personal Exploration Rover: Educational

assessment of a robotic exhibit for informal learning venue

The Personal Exploration Rover: The Ground-up Design, Deployment and Educational Evaluation of an Educational Robot for Unmediated Informal Learning Sites

Robotics brings together learning across mechanism, computation and interaction using the compelling model of real-time interaction with a physically instantiated intelligent device. The project described here is the third stage of the Personal Rover Project, which aims to produce technology, curriculum and evaluation techniques for use with after-school, out-of-school and informal learning environments mediated by robotics. Our most recent work has resulted in the Personal Exploration Rover (PER), whose goal is to create and evaluate a robot interaction that will educate members of the general public in an informal learning environment and capitalize on the current enthusiasm and excitement produced by NASA&apos;s Mars Exploration Rovers (MERs). We have two specific goals of teaching about the role of rovers as tools for scientific exploration and teaching about the importance of robot autonomy. To this effect we have designed an interactive, robotic museum exhibit which has been deployed at six locations across the United States. Here we describe the robot hardware and software designed for this task, the exhibits developed, and the results of formal evaluation of the exhibits &apos; educational impact on museum visitors

Impact of eastern dwarf mistletoe (Arceuthobium pusillum) on host white spruce (Picea glauca) development, growth and performance across multiple scales

Infection by eastern dwarf mistletoe (Arceuthobium pusillum) modifies needle and branch morphology and hastens white spruce (Picea glauca) mortality. We examined potential causal mechanisms and assessed the impacts of infection-induced alterations to host development and performance across scales ranging from needle hormone contents to bole expansion. Needles on infected branches (IBs) possessed higher total cytokinin (CK) and lower abscisic acid contents than needles on uninfected branches (UBs). IBs exhibited greater xylem growth than same-aged UBs, which is consistent with the promotive effect of CKs on vascular differentiation and organ sink strength. Elevated CK content may also explain the dense secondary and tertiary branching observed at the site of infection, i.e. the formation of ‘witches’ brooms’ with significantly lower light capture efficiencies. Observed hormone perturbations were consistent with higher rates of transpiration, lower water use efficiencies (WUEs) and more negative needle carbon isotope ratios observed for IBs. Observed reductions in needle size allowed IBs to compensate for reduced hydraulic conductivity. Severe infections resulted in dramatically decreased diameter growth of the bole. It seems likely that the modifications to host hormone contents by eastern dwarf mistletoe infection led white spruce trees to dedicate a disproportionate fraction of their photoassimilate and other resources to self-shaded branches with low WUE. This would have decreased the potential for fixed carbon accumulation, generating a decline in the whole-tree resource pool. As mistletoe infections grew in size and the number of IBs increased, this burden was manifested as increasingly greater reductions in bole growth