Precise radial velocities of giant stars IX. HD 59686 Ab: a massive circumstellar planet orbiting a giant star in a ~13.6 au eccentric binary system

Context: For over 12 yr, we have carried out a precise radial velocity survey of a sample of 373 G and K giant stars using the Hamilton \'Echelle Spectrograph at Lick Observatory. There are, among others, a number of multiple planetary systems in our sample as well as several planetary candidates in stellar binaries. Aims: We aim at detecting and characterizing substellar+stellar companions to the giant star HD 59686 A (HR 2877, HIP 36616). Methods: We obtained high precision radial velocity (RV) measurements of the star HD 59686 A. By fitting a Keplerian model to the periodic changes in the RVs, we can assess the nature of companions in the system. In order to discriminate between RV variations due to non-radial pulsation or stellar spots we used infrared RVs taken with the CRIRES spectrograph at the Very Large Telescope. Additionally, to further characterize the system, we obtain high-resolution images with LMIRCam at the Large Binocular Telescope. Results: We report the likely discovery of a giant planet with a mass of $m_{p}~\sin i=6.92_{-0.24}^{+0.18}~M_{Jup}$ orbiting at $a_{p}=1.0860_{-0.0007}^{+0.0006}$ au from the giant star HD 59686 A. Besides the planetary signal, we discover an eccentric ($e_{B}=0.729_{-0.003}^{+0.004}$) binary companion with a mass of $m_{B}~\sin i=0.5296_{-0.0008}^{+0.0011}~M_{Sun}$ orbiting at a semi-major axis of just $a_{B}=13.56_{-0.14}^{+0.18}$ au. Conclusions: The existence of the planet HD 59686 Ab in a tight eccentric binary system severely challenges standard giant planet formation theories and requires substantial improvements to such theories in tight binaries. Otherwise, alternative planet formation scenarios such as second generation planets or dynamical interactions in an early phase of the system's lifetime should be seriously considered in order to better understand the origin of this enigmatic planet.Comment: 14 pages, 11 figures, 2 tables. Accepted for publication in A&A. Updated version to match the published pape

BEAST detection of a brown dwarf and a low-mass stellar companion around the young bright B star HIP 81208

Recent observations from B-star Exoplanet Abundance Study (BEAST) have illustrated the existence of sub-stellar companions around very massive stars. In this paper, we present the detection of two lower mass companions to a relatively nearby ($148.7^{+1.5}_{-1.3}$ pc), young ($17^{+3}_{-4}$ Myr), bright (V=$6.632\pm0.006$ mag), $2.58\pm0.06~ M_{\odot}$ B9V star HIP 81208 residing in the Sco-Cen association, using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument at the Very Large Telescope (VLT) in Chile. Analysis of the photometry obtained gives mass estimates of $67^{+6}_{-7}~M_J$ for the inner companion and $0.135^{+0.010}_{-0.013}~M_{\odot}$ for the outer companion, indicating the former to be most likely a brown dwarf and the latter to be a low-mass star. The system is compact but unusual, as the orbital planes of the two companions are likely close to orthogonal. The preliminary orbital solutions we derived for the system indicate that the star and the two companions are likely in a Kozai resonance, rendering the system dynamically very interesting for future studies.Comment: 18 pages, 14 figures, 5 tables Accepted for publication in the 10. Planets and planetary systems section of A&

The B-Star Exoplanet Abundance Study: a co-moving 16-25 Mjup companion to the young binary system HIP 79098

Wide low-mass substellar companions are known to be very rare among low-mass stars, but appear to become increasingly common with increasing stellar mass. However, B-type stars, which are the most massive stars within ~150 pc of the Sun, have not yet been examined to the same extent as AFGKM-type stars in that regard. In order to address this issue, we launched the ongoing B-star Exoplanet Abundance Study (BEAST) to examine the frequency and properties of planets, brown dwarfs, and disks around B-type stars in the Scorpius-Centaurus (Sco-Cen) association; we also analyzed archival data of B-type stars in Sco-Cen. During this process, we identified a candidate substellar companion to the B9-type spectroscopic binary HIP 79098 AB, which we refer to as HIP 79098 (AB)b. The candidate had been previously reported in the literature, but was classified as a background contaminant on the basis of its peculiar colors. Here we demonstrate that the colors of HIP 79098 (AB)b are consistent with several recently discovered young and low-mass brown dwarfs, including other companions to stars in Sco-Cen. Furthermore, we show unambiguous common proper motion over a 15-year baseline, robustly identifying HIP 79098 (AB)b as a bona fide substellar circumbinary companion at a 345+/-6 AU projected separation to the B9-type stellar pair. With a model-dependent mass of 16-25 Mjup yielding a mass ratio of <1%, HIP 79098 (AB)b joins a growing number of substellar companions with planet-like mass ratios around massive stars. Our observations underline the importance of common proper motion analysis in the identification of physical companionship, and imply that additional companions could potentially remain hidden in the archives of purely photometric surveys.Comment: 9 pages, 6 figures, accepted for publication in A&

Differential Production of Nitric Oxide and Hydrogen Peroxide among <i>Drosophila melanogaster</i>, <i>Apis mellifera</i>, and <i>Mamestra brassicae</i> Immune-Activated Hemocytes after Exposure to Imidacloprid and Amitraz

Invertebrates have a diverse immune system that responds differently to stressors such as pesticides and pathogens, which leads to different degrees of susceptibility. Honeybees are facing a phenomenon called colony collapse disorder which is attributed to several factors including pesticides and pathogens. We applied an in vitro approach to assess the response of immune-activated hemocytes from Apis mellifera, Drosophila melanogaster and Mamestra brassicae after exposure to imidacloprid and amitraz. Hemocytes were exposed to the pesticides in single and co-exposures using zymosan A for immune activation. We measured the effect of these exposures on cell viability, nitric oxide (NO) production from 15 to 120 min and on extracellular hydrogen peroxide (H2O2) production after 3 h to assess potential alterations in the oxidative response. Our results indicate that NO and H2O2 production is more altered in honeybee hemocytes compared to D. melanogaster and M. brassicae cell lines. There is also a differential production at different time points after pesticide exposure between these insect species as contrasting effects were evident with the oxidative responses in hemocytes. The results imply that imidacloprid and amitraz act differently on the immune response among insect orders and may render honeybee colonies more susceptible to infection and pests

Actions to reduce the impact of construction products on indoor air: outcomes of the European project Healthy Air

The European project - HealthyAir is a network project involving six institutions in Europe on actions and activities that address the effects of construction products on indoor air. Different ways to improve indoor air quality were reviewed, ranging from source control to education of occupants on how to manage the built environment to achieve healthy and acceptable indoor air. Through literature study, organised workshops with scientific experts and building professionals as well as via interviews with three stakeholder groups: producers of construction products, architects and housing corporations; requirements for information, guidance and actions to improve indoor air quality were identified. These requirements formed the basis of a possible approach to improve indoor air quality: education and awareness, regulations and policies and further research and development

Procalcitonin to reduce exposure to antibiotics and individualise treatment in hospitalised old patients with pneumonia: a randomised study

International audienceBackground: Treating pneumonia in old patients remains challenging for clinicians. Moreover, bacterial antimicrobial resistance is a major public health threat.Objective: The PROPAGE study evaluated the interest of a strategy using serial measurements of procalcitonin (PCT) to reduce the duration of antibiotic therapy in old patients with pneumonia.Methods: PROPAGE took place from Dec.-2013 to Jun.-2016 in eight French geriatric units. It was a prospective, comparative, randomised, open-label study involving old patients (≥ 80 years) who had initiated antibiotic treatment for pneumonia in the previous 48 h. PCT was monitored in all patients and two decision-making PCT-based algorithms guided antibiotic therapy in patients from the PCT group.Results: 107 patients were randomised (PCT, n = 50; Control, n = 57). Antibiotic therapy exposure was reduced in the PCT group as compared to the Control group (median duration of antibiotic therapy, 8 vs. 10 days [rank-test, p = 0.001]; antibiotic persistence rates on Days 6 and 8, 54% and 44% vs. 91% and 72%) and no significant difference was found in recovery rate (84% vs. 89.5%; Pearson Chi² test, p = 0.402).Conclusion: Although, the superiority of the strategy was not tested using a composite criterion combining antibiotic therapy duration and recovery rate was not tested due to the small sample size, the present study showed that monitoring associated with PCT-guided algorithm could help shorten antibiotic treatment duration in the very old patients without detrimental effects. Measuring PCT levels between Day 4 and Day 6 could be helpful when making the decision regarding antibiotic discontinuation.Trial registration: NCT02173613. This study was first registered on 25/06/2014

BEAST detection of a brown dwarf and a low-mass stellar companion around the young bright B star HIP 81208

Recent observations by the B-star Exoplanet Abundance Study (BEAST) illustrate the existence of substellar companions around very massive stars. Here, we present the detection of two lower mass companions to a relatively nearby (148.7₋₁.₃⁺¹.⁵ pc), young (17₋₄⁺³ Myr), bright (V = 6.632 ± 0.006 mag), 2.58 ± 0.06 MʘB9V star HIP 81208 residing in the Sco-Cen association using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument at the Very Large Telescope (VLT) in Chile. Our analysis of the photometry obtained gives mass estimates of 67₋₇⁺⁶ MJ for the inner companion and 0.135₋₀.₀₁₃⁺⁰.⁰¹⁰ Mʘ for the outer companion, indicating that the former is most likely a brown dwarf and the latter a low-mass star. The system is compact but unusual, as the orbital planes of the two companions are likely close to orthogonal. The preliminary orbital solutions we derive for the system indicate that the star and the two companions are likely in a Kozai resonance, rendering the system dynamically very interesting for future studies.ISSN:0004-6361ISSN:1432-074