2,936 research outputs found

    Superthermal electron processes in the upper atmosphere of Uranus: Aurora and electroglow

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    Strong ultraviolet emissions from the upper atmosphere of Uranus suggest that both auroral and electroglow phenomena are of significant aeronomical consequences in the structure of the upper atmosphere. Combined modeling and data analysis were performed to determine the effect of electroglow and auroral phenomena on the global heat and atomic hydrogen budgets in the Uranus upper atmosphere. The results indicate that the auroral and electroglow heat sources are not adequate to explain the high exospheric temperature observed at Uranus, but that the atomic hydrogen supplied by these processes is more than sufficient to explain the observations. The various superthermal electron distributions modeled have significantly different efficiencies for the various processes such as UV emission, heating, ionization, and atomic hydrogen production, and produce quite different H2 band spectra. However, additional information on the UV spectra and global parameters is needed before modeling can be used to distinguish between the possible mechanisms for electroglow

    Winds of Planet Hosting Stars

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    The field of exoplanetary science is one of the most rapidly growing areas of astrophysical research. As more planets are discovered around other stars, new techniques have been developed that have allowed astronomers to begin to characterise them. Two of the most important factors in understanding the evolution of these planets, and potentially determining whether they are habitable, are the behaviour of the winds of the host star and the way in which they interact with the planet. The purpose of this project is to reconstruct the magnetic fields of planet hosting stars from spectropolarimetric observations, and to use these magnetic field maps to inform simulations of the stellar winds in those systems using the Block Adaptive Tree Solar-wind Roe Upwind Scheme (BATS-R-US) code. The BATS-R-US code was originally written to investigate the behaviour of the Solar wind, and so has been altered to be used in the context of other stellar systems. These simulations will give information about the velocity, pressure and density of the wind outward from the host star. They will also allow us to determine what influence the winds will have on the space weather environment of the planet. This paper presents the preliminary results of these simulations for the star τ\tau Bo\"otis, using a newly reconstructed magnetic field map based on previously published observations. These simulations show interesting structures in the wind velocity around the star, consistent with the complex topology of its magnetic field.Comment: 8 pages, 2 figures, accepted for publication in the peer-reviewed proceedings of the 14th Australian Space Research Conference, held at the University of South Australia, 29th September - 1st October 201

    Discovery of the magnetic field of the B1/B2V star \sigma Lupi

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    In our search for new magnetic massive stars we use the strongest indirect indicator of a magnetic field in B stars, which is periodic variability of UV stellar wind lines occurring in a velocity range symmetric around zero. Our aim is to obtain follow-up spectropolarimetry to search for a magnetic field in magnetic candidate stars. We quantify UV wind line variability, and analyse its time behaviour. The B1/B2V star sigma Lup emerged as a new magnetic candidate star. AAT spectropolarimetric measurements with SEMPOL were obtained. The stellar wind line variations of sigma Lup are similar to what is known in magnetic B stars, but no periodicity could be determined. We detected a longitudinal magnetic field with varying strength and amplitude of about 100 G with error bars of typically 20 G, which supports an oblique magnetic-rotator configuration. The equivalent width variations of the UV lines, the magnetic and the optical line variations are consistent with the well-known photometric period of 3.02 days, which we identify with the rotation period of the star. Additional observations with ESPaDOnS at CFHT strongly confirmed this discovery, and allowed to determine a precise magnetic period. Further analysis revealed that σ\sigma Lupi is a helium-strong star, with an enhanced nitrogen abundance and an underabundance of carbon, and has a spotted surface. We conclude that sigma Lup is a magnetic oblique rotator, and is a He-strong star. It is the 4th B star for which a magnetic field is discovered from studying only its wind variability. Like in the other magnetic B stars the wind emission originates in the magnetic equator, with maximum emission occurring when a magnetic pole points towards the Earth. The 3.02 d magnetic rotation period is consistent with the photometric period, with maximum light corresponding to maximum magnetic field. A full paper will be submitted to A&A.Comment: 4 pages, 5 figures, to appear in proceedings with AIP. Stellar polarimetry: From birth to death, Eds. Jennifer Hoffman, Barb Whitney, and Jon Bjorkma

    A protosolar nebula origin for the ices agglomerated by Comet 67P/Churyumov-Gerasimenko

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    The nature of the icy material accreted by comets during their formation in the outer regions of the protosolar nebula is a major open question in planetary science. Some scenarios of comet formation predict that these bodies agglomerated from crystalline ices condensed in the protosolar nebula. Concurrently, alternative scenarios suggest that comets accreted amorphous ice originating from the interstellar cloud or from the very distant regions of the protosolar nebula. On the basis of existing laboratory and modeling data, we find that the N2_2/CO and Ar/CO ratios measured in the coma of the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA instrument aboard the European Space Agency's Rosetta spacecraft match those predicted for gases trapped in clathrates. If these measurements are representative of the bulk N2_2/CO and Ar/CO ratios in 67P/Churyumov-Gerasimenko, it implies that the ices accreted by the comet formed in the nebula and do not originate from the interstellar medium, supporting the idea that the building blocks of outer solar system bodies have been formed from clathrates and possibly from pure crystalline ices. Moreover, because 67P/Churyumov-Gerasimenko is impoverished in Ar and N2_2, the volatile enrichments observed in Jupiter's atmosphere cannot be explained solely via the accretion of building blocks with similar compositions and require an additional delivery source. A potential source may be the accretion of gas from the nebula that has been progressively enriched in heavy elements due to photoevaporation.Comment: The Astrophysical Journal Letters, in pres

    The impact of LASPO on routes to justice

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    This research underlines the emotional, social, financial and mental health impacts for individuals who have attempted to resolve their legal problems without legal aid, following the implementation of the Legal Aid, Sentencing and Punishment of Offenders Act (LASPO) in 2013. LASPO introduced funding cuts to legal aid and narrowed the scope and financial eligibility criteria, with the result that fewer people could access legal advice and representation for problems in areas such as family, employment and welfare benefits law. We interviewed over 100 people in the Liverpool City Region, with problems in at least one of these areas of law, to understand how LASPO had affected their options for resolving those issues. We also interviewed a number of advice providers and legal aid practitioners, and analysed national data from Citizens Advice. Many participants reported significant financial deprivation as a result of trying but not being able to resolve their legal issues. Some were unable to afford food, adequate housing or other essentials. A lack of preventive legal help led to delays in resolution, which often made problems worse. There was also evidence that costs were passed to other parts of the public sector, including an increased reliance on welfare benefits as a result of unresolved employment issues. Family law • The high cost of legal fees is a key barrier to justice. Some participants who paid for legal advice or representation reported going into debt as a result. • People’s inability to pay for expert or specialist evidence without legal aid may have led to courts making decisions on the basis of insufficient information. • Cuts to legal aid have had a negative impact on children’s lives, especially in relation to child contact cases. Employment law • The main barriers to justice are the high cost of legal representation, the difficulty of navigating the tribunal process without support and a low level of knowledge about employment rights. • Many participants reported that the costs of bringing their claims to tribunal were disproportionate to the value of the claims. This deterred them from bringing claims and made it harder to find a solicitor willing to take their case. • Participants had fewer options for accessing third-sector specialist advice and representation. Those participants who went to tribunal had to represent themselves as a result, and in general they lacked the skills or experience to do this competently. Welfare benefits law • LASPO has significantly reduced the capacity of voluntary sector organisations to provide welfare law advice. There is almost no specialist advice left to provide support to appeal benefits decisions. • The removal of welfare benefits law from the scope of legal aid has exacerbated the impact of recent welfare reforms, which is likely to have affected disabled people disproportionately. Most participants tried multiple routes to resolve a single issue: attempting to resolve problems on their own, trying to access free advice and taking steps to get paid advice or representation before courts or tribunals. But without legal aid, almost all the participants struggled to solve their problems

    Do divorcing couples become happier by breaking up?

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    Divorce is a leap in the dark. The paper investigates whether people who split up actually become happier. Using the British Household Panel Survey, we can observe an individual's level of psychological well-being in the years before and after divorce. Our results show that divorcing couples reap psychological gains from the dissolution of their marriages. Men and women benefit equally. The paper also studies the effects of bereavement, of having dependant children and of remarriage. We measure well-being by using general health questionnaire and life satisfaction scores

    Note and Comment

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    Power of the US Supreme Court to Enforce Judgments Against States - In the year 1460, when the perogatives of sovereignty or at least of the Crown were asserted in England much more vigorously than they are today, the Counseill of the right high and mighty Prynce Richard Duc of York, brought into the Parliament Chambre a writyng conteignyng the clayme and title of the right, that the seid Duc pretended unto the Corones of Englond and of Fraunce, and Lordship of Trelond, and the same writyng delyvered to the Right Reverent Fader in God George Bishop of Excestre, Chaunceller of Englond, desiryng hym that the same writyng myght be opened to the Lordes Spirituelx and Temporelx assembled in this present Parlement, and that the seid Duc myght have brief and expedient answere thereof. Whereupon the lords, apparently embarrassed by this extraordinary manifestation of confidence in them, declared that the said writyng shuld be radde and herd, not to be answered without the Kyngs commaundement, for so moche as the mater is so high, and of soo grete wyght and poyse.\u27 Vhen four days later the petition was again urgently presented therupon incontynent all the seid Lordes Spirituelx and Temporelx went to the Kyngs high presence, and therunto opened and declared the seid mater, by the mouth of his said Chaunceller of Englond. The King was graciously pleased to command the lords that they should serche for to fynde in asmuch as in them was, all such thyngs as myght be objecte and leyde ayenst the cleyme and title of the seid Duc. And though the King\u27s command could scarcely be regarded as indicating a judicial inquiry, the lords in their extremity sent for the Kyngs Justices into the Parlement Chambre, to have their avis and Counsell in this behalf, * * * * sadly to take avisament therin, and to serche and fynde all such objections as myght be leyde ayenst the same, in fortefying of the Kynges right. Duke of York\u27s Claim to the Crown, 5 Rot. ParI., 375, I Wambaugh\u27s Cas. Const. Law, I

    Outdoor learning spaces: the case of forest school

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    © 2017 The Author. Area published by John Wiley & Sons Ltd on behalf of Royal Geographical Society (with the Institute of British Geographers). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.This paper contributes to the growing body of research concerning use of outdoor spaces by educators, and the increased use of informal and outdoor learning spaces when teaching primary school children. The research takes the example of forest school, a form of regular and repeated outdoor learning increasingly common in primary schools. This research focuses on how the learning space at forest school shapes the experience of children and forest school leaders as they engage in learning outside the classroom. The learning space is considered as a physical space, and also in a more metaphorical way as a space where different behaviours are permitted, and a space set apart from the national curriculum. Through semi-structured interviews with members of the community of practice of forest school leaders, the paper seeks to determine the significance of being outdoors on the forest school experience. How does this learning space differ from the classroom environment? What aspects of the forest school learning space support pupils’ experiences? How does the outdoor learning space affect teaching, and the dynamics of learning while at forest school? The research shows that the outdoor space provides new opportunities for children and teachers to interact and learn, and revealed how forest school leaders and children co-create a learning environment in which the boundaries between classroom and outdoor learning, teacher and pupil, are renegotiated to stimulate teaching and learning. Forest school practitioners see forest school as a separate learning space that is removed from the physical constraints of the classroom and pedagogical constraints of the national curriculum to provide a more flexible and responsive learning environment.Peer reviewe
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