Discovery of a New Deeply Eclipsing SU UMa-Type Dwarf Nova, IY UMa (= TmzV85)

We discovered a new deeply eclipsing SU UMa-type dwarf nova, IY UMa, which experienced a superoutburst in 2000 January. Our monitoring revealed two distinct outbursts, which suggest a superoutburst interval of ~800 d, or its half, and an outburst amplitude of 5.4 mag. From time-series photometry during the superoutburst, we determined a superhump and orbital period of 0.07588 d and 0.0739132 d, respectively.Comment: 5 pages, 3 figures, accepted by PASJ lette

Photometric study of new southern SU UMa-type dwarf novae and candidates: V877 Ara, KK Tel and PU CMa

We photometrically observed three dwarf novae V877 Ara, KK Tel and PU CMa. We discovered undisputed presence of superhumps in V877 Ara and KK Tel, with mean periods of 0.08411(2) d and 0.08808(3) d, respectively. Both V877 Ara and KK Tel are confirmed to belong to long-period SU UMa-type dwarf novae. In V877 Ara, we found a large decrease of the superhump period (dot(P)/P = -14.5 +/- 2.1 x 10^(-5)). There is evidence that the period of KK Tel decreased at a similar or a more exceptional rate. Coupled with the past studies of superhump period changes, these findings suggest that a previously neglected diversity of phenomena is present in long-period SU UMa-type dwarf novae. The present discovery of a diversity in long-period SU UMa-type systems would become an additional step toward a full understanding the dwarf nova phenomenon. PU CMa is shown to be an excellent candidate for an SU UMa-type dwarf nova. We examined the outburst properties of these dwarf novae, and derived characteristic outburst recurrence times. Combined with the recently published measurement of the orbital period of PU CMa, we propose that PU CMa is the first object filling the gap between the extreme WZ Sge-type and ER UMa-type stars.Comment: 12 pages, 14 figures, accepted for publication in MNRA

'The language of the naked facts': Joseph Priestley on language and revealed religion

Joseph Priestley (1733-1804) is usually remembered for his experiments in natural philosophy and celebrated for his isolation of the gas we now call oxygen. However, Priestley had a wide range of interests and published extensively on education, history, politics, political philosophy, language, theology and religion. He dedicated his life to elucidating a coherent set of epistemological, metaphysical and theological principles which he believed explained the human mind, the natural world and the nature of God and revelation. Recent studies of Priestley have emphasised the difficulties that arise from isolating the various aspects of his thought and the fruitful outcome of uncovering the many connections between his diverse areas of study. With this in mind, the present dissertation aims to elucidate the relationship between two aspects of Priestley’s thought that have not previously been studied together. It examines his theory of language and argument alongside his work on theology and the evidences of revelation. Chapter One provides an overview of Priestley’s epistemology, focusing on his work on induction, judgment and assent. Chapter Two looks at Priestley’s analysis of the role of the passions in our assent to propositions and the progressive generation of the personality, while paying particular attention to the origins of figurative language. Chapter Three examines Priestley’s theory of language development including the relationship between figurative language and the extension of vocabulary and the close connection between language and culture. Chapter Four demonstrates that Priestley’s discussion of the evidences of revealed religion is structured around his theory of assent and judgment. It also explains how assent to revelation is essential for the generation and transcendence of the ‘self’. Chapter Five brings all the themes of the dissertation together in a discussion of Priestley’s rational theology and examines his analysis of figurative language in scripture

A New SU UMa-Type Dwarf Nova, QW Serpentis (= TmzV46)

We report on the results of the QW Ser campaign which has been continued from 2000 to 2003 by the VSNET collaboration team. Four long outbursts and many short ones were caught during this period. Our intensive photometric observations revealed superhumps with a period of 0.07700(4) d during all four superoutbursts, proving the SU UMa nature of this star. The recurrence cycles of the normal outbursts and the superoutbursts were measured to be $\sim$50 days and 240(30) days, respectively. The change rate of the superhump period was -5.8x10^{-5}. The distance and the X-ray luminosity in the range of 0.5-2.4 keV are estimated to be 380(60) pc and log L_x = 31.0 \pm 0.1 erg s^{-1}. These properties have typical values for an SU UMa-type dwarf nova with this superhump period.Comment: 9 pages, 12 figures, to appear in the VSNET special issue of PAS

Translation, Adaptation and Validation of the Coronary Revascularization Outcome Questionnaire (CROQ) into Greek

Date of Acceptance: 31/05/2015Evaluating the impact of coronary revascularization on patients’ health related quality of life with a patient-based and disease-specific tool is important for drawing conclusions about treatment and outcomes. This study reports on the translation, adaptation and psychometric evaluation of a Greek version of the Coronary Revascularization Outcome Questionnaire (CROQ-Gr)Peer reviewe

Swift observations of the X-ray and UV evolution of V2491 Cyg (Nova Cyg 2008 No. 2)

We present extensive, high-density Swift observations of V2491 Cyg (Nova Cyg 2008 No. 2). Observing the X-ray emission from only one day after the nova discovery, the source is followed through the initial brightening, the Super-Soft Source phase and back to the pre-outburst flux level. The evolution of the spectrum throughout the outburst is demonstrated. The UV and X-ray light-curves follow very different paths, although changes occur in them around the same times, indicating a link between the bands. Flickering in the late-time X-ray data indicates the resumption of accretion. We show that if the white dwarf is magnetic, it would be among the most magnetic known; the lack of a periodic signal in our later data argues against a magnetic white dwarf, however. We also discuss the possibility that V2491 Cyg is a recurrent nova, providing recurrence timescale estimates.Comment: 12 pages, 8 figure (2 in colour), accepted for publication in MNRA

Dwarf novae in the Hamburg quasar survey : rarer than expected

Aims. We report the discovery of five new dwarf novae that were spectroscopically identified in the Hamburg Quasar Survey (HQS),and discuss the properties of the sample of new dwarf novae from the HQS. Methods. Follow-up time-resolved spectroscopy and photometry have been obtained to characterise the new systems. Results. The orbital periods determined from analyses of the radial velocity variations and/or orbital photometric variability are Porb 105.1min or Porb 109.9min for HS 0417+7445, Porb = 114.3 ± 2.7min for HS 1016+3412, Porb = 92.66 ± 0.17 min for HS 1340+1524, Porb = 272.317 ± 0.001 min for HS 1857+7127, and Porb = 258.02 ± 0.56 min for HS 2214+2845. HS 1857+7127 is found to be partially eclipsing. In HS 2214+2845 the secondary star of spectral type M3 ± 1 is clearly detected, and we estimate the distance to the system to be d = 390 ± 40 pc. We recorded one superoutburst of HS 0417+7445, identifying the system as a SUUMatype dwarf nova. HS 1016+3412 and HS 1340+1524 have rare outbursts, and their subtype is yet undetermined. HS 1857+7127 frequently varies in brightness and may be a ZCam-type dwarf nova. HS 2214+2845 is a UGem-type dwarf nova with a most likely cycle length of 71 d. Conclusions. To date, 14 new dwarf novae have been identified in the HQS. The ratio of short-period (3 h)systems of this sample is 1.3, much smaller compared to the ratio of 2.7 found for all known dwarf novae. The HQS dwarf novae display typically infrequent or low-amplitude outburst activity, underlining the strength of spectroscopic selection in identifying new CVs independently of their variability. The spectroscopic properties of short-period CVs in the HQS, newly identified and previously known, suggest that most, or possibly all of them are still evolving towards the minimum period. Their total number agrees with the predictions of population models within an order of magnitude. However, the bulk of all CVs is predicted to have evolved past the minimum period, and those systems remain unidentified. This suggests that those post-bounce systems have markedly weaker Hβ emission lines compared to the average known short-period CVs, and undergo no or extremely rare outbursts