Now showing items 1-15 of 15

    • Detection of an increasing orbital period in the subdwarf B eclipsing system NSVS 14256825 

      Kilkenny, David; Koen, Chris (Oxford University Press, 2012)
      New timings of eclipses made in 2010 and 2011 are presented for the hot subdwarf B (sdB) eclipsing binary NSVS 14256825. Composed of an sdB star and a much cooler companion, with a period near 0.1104 days, this system ...
    • EC 10246-2707: a new eclipsing sdB + M dwarf binary⋆ 

      Barlow, B.N.; Kilkenny, David; Drechsel, H.; Dunlap, B.H. (OUP, 2013)
      We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Similar to other HW Vir-type binaries, the ...
    • The Edinburgh-Cape Blue Object Survey - III. Zone 2; galactic latitudes -30? > b > -40? 

      Kilkenny, David; Koen, Chris; Hambly, N.; MacGillivray, H.; Stobie, R. S.; O’Donoghue, D. (Oxford University Press, 2013)
      The Edinburgh–Cape Blue Object Survey seeks to identify point sources with an ultraviolet excess. Results for zone 2 of the survey are presented here, covering that part of the South Galactic Cap between 30◦ and 40◦ from ...
    • Further observations of Hipparcos red stars and standards for UBV(RI)C photometry 

      Kilkenny, David; Koen, Chris; van Wyk, F.; Marang, F.; Cooper, D. (Oxford University Press, 2007)
      We present homogeneous and standardized UBV(RI)C JHK photometry for over 100 M stars selected from an earlier paper on the basis of apparent photometric constancy. L photometry has been obtained for stars brighter than ...
    • HE 0230−4323 revisited: a new rapidly pulsating sdB star 

      Kilkenny, David; Koen, Chris; Worters, H. (Oxford University Press, 2010)
      HE 0230−4323 is a hot sdB star in a binary system. An earlier work demonstrated that the light curve of the system shows a strong (∼4 per cent) reflection effect and also appears to exhibit photometric variations of the ...
    • Hot subdwarf stars in close-up view IV. Helium abundances and the 3He isotopic anomaly of subdwarf B stars 

      Geier, S.; Edelmann, H.; Kilkenny, David; O'Donoghue, D.; Marsh, T.R.; Copperwheat, C. (EDP Sciences, 2013)
      Atmospheric parameters and helium abundances of 44 bright subdwarf B stars have been determined. More than half of our sample consists of newly discovered stars from the Edinburgh Cape survey. We showed that effective ...
    • Improved SAAO–2MASS photometry transformations 

      Koen, Chris; Marang, F.; Kilkenny, David; Jacobs, C. (Oxford University Press, 2007)
      Near-infrared photometry of 599 stars is used to calculate transformations from the South African Astronomical Observatory (SAAO) JHK system to the Two-Micron All-Sky Survey (2MASS) JHKS system. Both several-term formal ...
    • Long-term eclipse timing of white dwarf binaries: an observational hint of a magnetic mechanism at work 

      Bours, M.C.P.; Kilkenny, David (Oxford University Press, 2016)
      We present a long-term programme for timing the eclipses of white dwarfs in close binaries to measure apparent and/or real variations in their orbital periods. Our programme includes 67 close binaries, both detached and ...
    • The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again 

      Tisserand, P.; Clayton, G.; Kilkenny, David; Welch, D. L.; Wyrzykowsk, L.; Pilecki, B. (EDP Sciences, 2013)
      CONTEXT: R Coronae Borealis stars( RCBs) are rare, hydrogen-deficient, carbon rich super giant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found ...
    • Periodic variations in the O-C diagrams of five pulsation frequencies of the DB white dwarf EC 20058-5234 

      Dalessio, J.; Sullivan, D. J.; Kilkenny, David; Provencal, J. L.; Shipman, H. L.; Sullivan, T.; Fraga, L.; Sefako, R. (American Physical Society, 2013)
      Variations in the pulsation arrival time of five independent pulsation frequencies of the DB white dwarf EC 20058−5234 individually imitate the effects of reflex motion induced by a planet or companion but are inconsistent ...
    • A search for p-mode pulsations in white dwarf stars using the Berkeley Visible Imaging Tube detector 

      Kilkenny, David; Welsh, B.Y.; Koen, Chris; Gulbis, A.A.S.; Kotze, M.M. (Oxford University Press, 2014)
      We present high-speed photometry (resolution 0.1 s) obtained during the commissioning of the Berkely Visible Imaging Tube system on the Southern African Large Telescope (SALT). The observations were an attempt to search ...
    • Short-period pulsating hot-subdwarf stars observed by TESS: I. Southern ecliptic hemisphere 

      Baran, Andrzej S.; van Grootel, Valérie; Kilkenny, David (EDP Sciences, 2023)
      We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere ...
    • Two new pulsating hot subdwarf stars from the Edinburgh-Cape survey 

      Kilkenny, David; O'Donoghue, D.; Crause, L.; Engelbrecht, C.; Hambly, N.; MacGillivray, H. (Oxford University Press, 2009)
      We report the discovery of very rapid pulsations in two hot subdwarf stars from the Edinburgh- Cape blue object survey. The short periods, small amplitudes and multiperiodicity establish these stars as members of the ...
    • Two new variable sdB stars, HE 0218−3437 and LB 1516 

      Koen, Chris; Kilkenny, David; Pretorius, M.L.; Frew, D.J. (Oxford University Press, 2010)
      We present photometry which shows that two known hot subdwarf stars, HE 0218−3437 and LB 1516, are variable. LB 1516 exhibits several frequencies in the range 12–25 cycles d−1 (periods of about 1–2 h) with amplitudes ...
    • UBV(RI)C JHK observations of Hipparcos-selected nearby stars 

      Koen, Chris; Kilkenny, David; van Wyk, F.; Marang, F. (Oxford University Press, 2010)
      We present homogeneous, standardized UBV(RI)C photometry for over 700 nearby stars selected on the basis of Hipparcos parallaxes. Additionally, we list JHK photometry for about half of these stars, as well as L photometry ...