Discovery of a Binary Centaur

We have identified a binary companion to (42355) 2002 CR46 in our ongoing deep survey using the Hubble Space Telescope's High Resolution Camera. It is the first companion to be found around an object in a non-resonant orbit that crosses the orbits of giant planets. Objects in orbits of this kind, the Centaurs, have experienced repeated strong scattering with one or more giant planets and therefore the survival of binaries in this transient population has been in question. Monte Carlo simulations suggest, however, that binaries in (42355) 2002 CR46 -like heliocentric orbits have a high probability of survival for reasonable estimates of the binary's still-unknown system mass and separation. Because Centaurs are thought to be precursors to short period comets, the question of the existence of binary comets naturally arises; none has yet been definitively identified. The discovery of one binary in a sample of eight observed by HST suggests that binaries in this population may not be uncommon.Comment: 20 pages, 4 figures, 1 table accepted for publication in Icaru

Temporal change in maternal dietary intake during pregnancy and lactation between and within 2 pregnancy cohorts assembled in the United Kingdom

Background: The association between maternal and infant dietary exposures and risk of allergic disease development is an area of considerable scientific uncertainty. Objective: This study aims to compare dietary habits during pregnancy and lactation in two pre-birth cohorts from the same location approximately 10 years apart, a timeframe characterised by changes in government dietary advice. Methods: The FAIR cohort is an unselected birth cohort born between 2001-2002. The 3rd generation cohort was born between 2010-2018. Both cohorts were established on the Isle of Wight (UK) to investigate prevalence of allergic diseases. Nutrition and allergy data was collected prospectively from recruitment and throughout the infant’s early life. Here we present dietary data collected in the third trimester of pregnancy and at three months of age. Differences between cohorts were tested using t-tests, Wilcoxon rank sum tests, chi-squared and Fisher’s exact tests. Results: Data was available for 1331 participants (969 FAIR and 362 3rd generation). The proportion of mothers that reported excluding peanuts during pregnancy was significantly lower for the 3rd generation compared to the FAIR cohort (16.0% vs. 55.6%, p < 0.01). Cohort membership, primiparity, and maternal education were significantly associated with excluding peanuts during pregnancy (p < 0.01). The proportion of mothers who reported excluding any foods during breastfeeding was significantly lower for the 3rd generation compared to the FAIR cohort (22.8% vs. 43.4%, p < 0.01). Conclusion: Maternal exclusion of peanut during pregnancy was lower for mothers giving birth between 2012-2018, compared to mothers giving birth between 2001-2002

Overview of the New Horizons Science Payload

The New Horizons mission was launched on 2006 January 19, and the spacecraft is heading for a flyby encounter with the Pluto system in the summer of 2015. The challenges associated with sending a spacecraft to Pluto in less than 10 years and performing an ambitious suite of scientific investigations at such large heliocentric distances (> 32 AU) are formidable and required the development of lightweight, low power, and highly sensitive instruments. This paper provides an overview of the New Horizons science payload, which is comprised of seven instruments. Alice provides spatially resolved ultraviolet spectroscopy. The Ralph instrument has two components: the Multicolor Visible Imaging Camera (MVIC), which performs panchromatic and color imaging, and the Linear Etalon Imaging Spectral Array (LEISA), which provides near-infrared spectroscopic mapping capabilities. The Radio Experiment (REX) is a component of the New Horizons telecommunications system that provides both occultation and radiometry capabilities. The Long Range Reconnaissance Imager (LORRI) provides high sensitivity, high spatial resolution optical imaging capabilities. The Solar Wind at Pluto (SWAP) instrument measures the density and speed of solar wind particles. The Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) measures energetic protons and CNO ions. The Venetia Burney Student Dust Counter (VB-SDC) is used to record dust particle impacts during the cruise phases of the mission.Comment: 17 pages, 4 figures, 1 table; To appear in a special volume of Space Science Reviews on the New Horizons missio

Detection of a Satellite of the Trojan Asteroid (3548) Eurybates—A Lucy Mission Target

We describe the discovery of a satellite of the Trojan asteroid (3548) Eurybates in images obtained with the Hubble Space Telescope. The satellite was detected on three separate epochs, two in 2018 September and one in 2020 January. The satellite has a brightness in all three epochs consistent with an effective diameter of d₂ = 1.2 ± 0.4 km. The projected separation from Eurybates was s ~ 1700–2300 km and varied in position, consistent with a large range of possible orbits. Eurybates is a target of the Lucy Discovery mission and the early detection of a satellite provides an opportunity for a significant expansion of the scientific return from this encounter