Weak magnetic fields in white dwarfs and their direct progenitors?

We have carried out a re-analysis of polarimetric data of central stars of planetary nebulae, hot subdwarfs, and white dwarfs taken with FORS1 (FOcal Reducer and low dispersion Spectrograph) on the VLT (Very Large Telescope), and added a large number of new observations in order to increase the sample. A careful analysis of the observations using only one wavelength calibration for the polarimetrically analysed spectra and for all positions of the retarder plate of the spectrograph is crucial in order to avoid spurious signals. We find that the previous detections of magnetic fields in subdwarfs and central stars could not be confirmed while about 10% of the observed white dwarfs have magnetic fields at the kilogauss level.Comment: 6 pages, Proceedings of the 18th European White Dwarf Workshop, ASP Conference Serie

Exoplanet properties from Lick, Keck and AAT

Doppler-shift measurements with a remarkable precision of Δλ/λ=3×10-9, corresponding to velocities of 1 m s-1, have been made repeatedly of 2500 stars located within 300 light years. The observed gravitational perturbations of the stars have revealed 250 orbiting planets, with 27 that cross in front of the host star, blocking a fraction of the starlight to allow measurement of the planet's mass, radius and density. Two new discoveries are the first good analog of Jupiter (HD 154345b) and the first system of five planets (55 Cancri). The predominantly eccentric orbits of exoplanets probably result from planet planet gravitational interactions or angular momentum exchange by mean-motion resonances. The planet mass distribution ranges from ~15 MJUP to as low as ~5 MEarth and rises toward lower masses as dN/dM~M-1.1. The distribution with orbital distance, a, rises (in logarithmic intervals) as dN/d log a~a+0.4. Extrapolation and integration suggests that 19% of all Sun-like stars harbor a gas-giant planet within 20 AU, but there remains considerable incompleteness for large orbits. Beyond 20 AU, the occurrence of gas-giant planets may be less than a few per cent as protoplanetary disk material there has lower densities and is vulnerable to destruction. Jupiter-mass planets occur more commonly around more massive stars than low mass stars. The transit of the Neptune-mass planet, Gliese 436b, yields a density of 1.55 g cm-3 suggesting that its interior has an iron silicate core surrounded by an envelope of water ice and an outer H He shell. Planets with masses as low as five Earth-masses may be commonly composed of iron nickel, rock and water along with significant amounts of H and He, making the term 'super-Earth' misleading. The transiting planet HD147506b has high orbital eccentricity but no significant orbital inclination to the line of sight, presenting a puzzle about its history. Its orbit together with the mean motion resonances of 4 of the 22 multi-planet systems provides further evidence for the role of planet planet interactions in shaping planetary architectures

Cool Jupiters greatly outnumber their toasty siblings : Occurrence rates from the Anglo-Australian Planet Search

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Our understanding of planetary systems different to our own has grown dramatically in the past 30 yr. However, our efforts to ascertain the degree to which the Solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. On the basis of such surveys, one might consider our planetary system highly unusual - but the reality is that we are only now beginning to uncover the true picture. In this work, we use the full 18-yr archive of data from the Anglo-Australian Planet Search to examine the abundance of 'cool Jupiters' - analogues to the Solar system's giant planets, Jupiter and Saturn. We find that such planets are intrinsically far more common through the cosmos than their siblings, the hot Jupiters.We find that the occurrence rate of such 'cool Jupiters' is 6.73 +2.09 -1.13 per cent, almost an order of magnitude higher than the occurrence of hot Jupiters (at 0.84 +0.70 -0.20 per cent). We also find that the occurrence rate of giant planets is essentially constant beyond orbital distances of ~1 au. Our results reinforce the importance of legacy radial velocity surveys for the understanding of the Solar system's place in the cosmos.Peer reviewe

Eradication of Pseudomonas aeruginosa biofilms on cultured airway cells by a fosfomycin/tobramycin antibiotic combination

Chronic biofilm formation by Pseudomonas aeruginosa in cystic fibrosis (CF) lungs is a major cause of morbidity and mortality for patients with CF. To gain insights into effectiveness of novel anti-infective therapies, the inhibitory effects of fosfomycin, tobramycin, and a 4:1 (wt/wt) fosfomycin/tobramycin combination (FTI) on Pseudomonas aeruginosa biofilms grown on cultured human CF-derived airway cells (CFBE41o-) were investigated. In preformed biofilms treated for 16 h with antibiotics, P. aeruginosa CFU per mL were reduced 4 log10 units by both FTI and tobramycin at 256 mg L(-1) , while fosfomycin alone had no effect. Importantly, the FTI treatment contained five times less tobramycin than the tobramycin-alone treatment. Inhibition of initial biofilm formation was achieved at 64 mg L(-1) FTI and 16 mg L(-1) tobramycin. Fosfomycin (1024 mg L(-1)) did not inhibit biofilm formation. Cytotoxicity was also determined by measuring lactate dehydrogenase (LDH). Intriguingly, sub-inhibitory concentrations of FTI (16 mg L(-1)) and tobramycin (4 mg L(-1)) and high concentrations of fosfomycin (1024 mg L(-1)) prevented bacterially mediated airway cell toxicity without a corresponding reduction in CFU. Overall, it was observed that FTI and tobramycin demonstrated comparable activity on biofilm formation and disruption. Decreased administration of tobramycin upon treatment with FTI might lead to a decrease in negative side effects of aminoglycosides

Detection of Planetary and Stellar Companions to Neighboring Stars via a Combination of Radial Velocity and Direct Imaging Techniques

13 pages, 6 figures, 4 tables, accepted for publication in the Astronomical Journal (submitted 25 Feb 2019; accepted 28 April 2019). Machine readable tables and Posteriors from the RadVel fits are available here: http://stephenkane.net/rvfits.tarThe sensitivities of radial velocity (RV) surveys for exoplanet detection are extending to increasingly longer orbital periods, where companions with periods of several years are now being regularly discovered. Companions with orbital periods that exceed the duration of the survey manifest in the data as an incomplete orbit or linear trend, a feature that can either present as the sole detectable companion to the host star, or as an additional signal overlain on the signatures of previously discovered companion(s). A diagnostic that can confirm or constrain scenarios in which the trend is caused by an unseen stellar rather than planetary companion is the use of high-contrast imaging observations. Here, we present RV data from the Anglo-Australian Planet Search (AAPS) for 20 stars that show evidence of orbiting companions. Of these, six companions have resolved orbits, with three that lie in the planetary regime. Two of these (HD 92987b and HD 221420b) are new discoveries. Follow-up observations using the Differential Speckle Survey Instrument (DSSI) on the Gemini South telescope revealed that 5 of the 20 monitored companions are likely stellar in nature. We use the sensitivity of the AAPS and DSSI data to place constraints on the mass of the companions for the remaining systems. Our analysis shows that a planetary-mass companion provides the most likely self-consistent explanation of the data for many of the remaining systems.Peer reviewedFinal Accepted Versio

Uninterested youth? Young people's attitudes towards party politics in Britain

Following the outcome of the 2001 and 2005 General Elections, when the numbers of abstainers outweighed the numbers of Labour voters on both occasions, much attention has focused upon the state of British democracy and how to enthuse the electorate, especially young people. While the government is exploring ways to make the whole process of voting easier, it may be failing to tackle the real problem - that youth appear to find the business of politics uninviting and irrelevant. This paper examines data derived from a nationwide survey of over 700 young people in order to shed light on what lies at the heart of young people's apparent disengagement from formal politics in Britain - political apathy or a sense of political alienation. The findings reveal that they support the democratic process, but are sceptical of the way the British political system is organised and led, and are turned off by politicians and the political parties. However, there is no uniform youth orientation to politics, and the data indicate that views differ according to social class, educational history, and also gender. However both ethnicity and region of the country in which young people live seem to have little influence in structuring political attitudes and behaviour

Time-series Spectroscopy of Pulsating sdB stars III: Line Indices of PG1605+072

We present the detection and analysis of line index variations in the pulsating sdB star PG 1605+072. We have found a strong dependence of line index amplitude on Balmer line order, with high-order Balmer line amplitudes up to 10 times larger than H-beta. Using a simple model, we have found that the line index may not only be dependent on temperature, as is usually assumed for oscillating stars, but also on surface gravity. This information will provide another set of observables that can be used for mode identification of sdBs.Comment: 8 pages, 9 figures, to appear in MNRAS. A high resolution version of Figure 3 can be found at http://www.sternwarte.uni-erlangen.de/~ai25/MC852-fig3.ep

European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for colorectal neuroendocrine tumours.

This ENETS guidance paper, developed by a multidisciplinary working group, provides an update on the previous colorectal guidance paper in a different format. Guided by key clinical questions practical advice on the diagnosis and management of neuroendocrine tumours (NET) of the caecum, colon, and rectum is provided. Although covered in one guidance paper colorectal NET comprises a heterogeneous group of neoplasms. The most common rectal NET are often small G1 tumours that can be treated by adequate endoscopic resection techniques. Evidence from prospective clinical trials on the treatment of metastatic colorectal NET is limited and discussion of patients in experienced multidisciplinary tumour boards strongly recommended. Neuroendocrine carcinomas (NEC) and mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) are discussed in a separate guidance paper

The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa

We introduce the Pan-Pacific Planet Search, a survey of 170 metal-rich Southern hemisphere subgiants using the 3.9m Anglo-Australian Telescope. We report the first discovery from this program, a giant planet orbiting 7 CMa (HD 47205) with a period of 763+/-17 days, eccentricity e=0.14+/-0.06, and m sin i=2.6+/-0.6 M_jup. The host star is a K giant with a mass of 1.5+/-0.3 M_sun and metallicity [Fe/H]=0.21+/-0.10. The mass and period of 7 CMa b are typical of planets which have been found to orbit intermediate-mass stars (M*>1.3 M_sun). Hipparcos photometry shows this star to be stable to 0.0004 mag on the radial-velocity period, giving confidence that this signal can be attributed to reflex motion caused by an orbiting planet.Comment: Accepted for publication in Ap