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Öğe A multiwavelength study of CC Eridani(2004) Slee, O.B.; Budding, E.; Carter, B.D.; Mengel, M.W.; Waite, I.; Donati, J.-F.Radio and optical observations from December 2001 and January 2002 of the active RS CVn-like binary CC Eri are presented. The star was monitored at 4.80 and 8.64 GHz over 3 × 12 h allocations with the Australia Telescope Compact Array on 28 to 30 December 2001. The Anglo-Australian Telescope was used for simultaneous optical spectropolarimetry during a 0.5 h period on 30 December. Data from four nights of broadband photometry gathered around the same period are also included in this present multiwavelength study. The low levels of radio emission were circularly polarised at ~20% with slightly positive spectral indices of ?0.26. Two flare-like increases were observed on successive nights with steep positive spectral indices and no detectable polarisation. Cross-correlation analysis of the 4.80 and 8.64 GHz intensities over the stronger flare showed that the higher frequency emission preceded that at the lower frequency by ?5 min, a result consistent with the propagation of a hydromagnetic disturbance outwards through the corona. On the same night, a significant cross-correlation in the 'quiescent' emission indicates the presence of micro-flaring, although its low intensity does not permit the evaluation of a time delay. The emission parameters on the three nights are compatible with a gyrosyncrotron mechanism, in which the radio source becomes optically thick during strong flaring. We develop a simple model, which is based on assuming that the number of radiating electrons is a given function of the magnetic field in the source region, and derive feasible values for the field, source radius, and number of emitting electrons, which are not strongly dependent on the field modelling function or the aspect ratio of the source. Spectropolarimetry demonstrates the presence of a strong surface magnetic field. Optical photometry, covering a sufficient amount of the orbit, indicates a maculation region of significant size (?14° radius). The results help develop a three-dimensional picture of a large stellar magnetically active region and encourage more detailed follow-up multiwavelength studies of this and similar stars. © Astronomical Society of Australia 2004.Öğe A multiwavelength study of the M dwarf binary YY Geminorum(Oxford Univ Press, 2015) Butler, C. J.; Erkan, N.; Budding, E.; Doyle, J. G.; Foing, B.; Bromage, G. E.; Kellett, B. J.We review the results of the 1988 multiwavelength campaign on the late-type eclipsing binary YY Geminorum. Observations include: broad-band optical and near-infrared photometry, simultaneous optical and ultraviolet (IUE) spectroscopy, X-ray (Ginga) and radio (VLA) data. From models fitted to the optical light curves, fundamental physical parameters have been determined together with evidence for transient maculations (spots) located near quadrature longitudes and intermediate latitudes. Eclipses were observed at optical, ultraviolet and radio wavelengths. Significant drops in 6 cm radio emission near the phases of both primary and secondary eclipse indicate relatively compact radio emitting volumes that may lie between the binary components. IUE observations during secondary eclipse are indicative of a uniform chromosphere saturated with Mg II emission and an extended volume of Ly alpha emission. Profile fitting of high-dispersion Ha spectra confirms the chromospheric saturation and indicates significant Ha opacity to heights of a few per cent of the photospheric radius. There is evidence for an enhanced Ha emission region visible near phase 0.25-0.35 which may be associated with a large spot on the primary and with two small optical flares which were also observed at other wavelengths: one in microwave radiation and the other in X-rays. For both flares, L-X/L-opt is consistent with energy release in closed magnetic structures.Öğe Absolute parameters of young stars - II. V831 Centauri(Oxford Univ Press, 2010) Budding, E.; Erdem, A.; Inlek, G.; Demircan, O.Literature photometry and new high-resolution spectroscopy of V831 Cen are presented and analysed. Light and radial velocity curve fittings confirm the central pair of this young multiple system to be close to contact. Absolute parameters are found as follows: M-1 = 4.08 +/- 0.07 M-circle dot, M-2 = 3.35 +/- 0.06 M-circle dot, R-1 = 2.38 +/- 0.03 R-circle dot, R-2 = 2.25 +/- 0.03 R-circle dot, T-1 = 13 000 +/- 300 K, T-2 = 11 800 +/- 300 K; distance of 110 +/- 10 pc and age of similar to 20 +/- 5 Myr. Detailed examination of the spectrograms indicates the third component (V831 Cen B) to be an Ap star. The orbit of the third star about the close binary is analysed using historic astrometric measurements. This allows an estimate of the third star's mass to be about 2.5 M-circle dot, but this is sensitive to the adopted distance and inclination values. It is, however, confirmed by the measured radial velocity of the third star. To some extent, such analysis can also be applied to the fourth star (V831 Cen C). The derived properties can be checked against the system's membership of the Scorpius-Centaurus OB2 association.Öğe Absolute parameters of young stars: GG Lup and ?1 Sco(Oxford Univ Press, 2015) Budding, E.; Butland, R.; Blackford, M.New high-resolution spectroscopy and BVR photometry, together with literature data, on the Gould's Belt close binary systems GG Lup and mu(1) Sco are presented and analysed. In the case of GG Lup, light and radial velocity curve fittings confirm a near-main-sequence picture of a pair of close stars. Absolute parameters are found, to within a fewper cent, thus: M-1 = 4.16 +/- 0.12, M-2 = 2.64 +/- 0.12 (M-circle dot); R-1 = 2.42 +/- 0.05, R-2 = 1.79 +/- 0.04 (R-circle dot); T-1 similar to 13 000, T-2 similar to 10 600 (K); photometric distance similar to 160 (pc). The high eccentricity and relatively short period (105 yr) of apsidal revolution may be related to an apparent 'slow B-type pulsator' oscillation. Disturbances of the outer envelope of at least one of the components then compromise comparisons to standard evolutionary models, at least regarding the age of the system. A rate of apsidal advance is derived, which allows a check on the mean internal structure constant (k(2)) over bar +/- 0.0058 +/- 0.0004. This is in agreement with values recently derived for young stars of solar composition and mass similar to 3 M-circle dot. For mu(1) Sco, we agree with previous authors that the secondary component is considerably oversized for its mass, implying binary (interactive) stellar evolution, probably of the ` Case A' type. The primary appears relatively little affected by this evolution, however. Its parameters show consistency with a star of its derived mass at age about 13 Myr, consistent with the star's membership of the Sco-Cen OB2 Association. The absolute parameters are as follows: M-1 = 8.3 +/- 1.0, M-2 = 4.6 +/- 1.0 (M circle dot); R-1 = 3.9 +/- 0.3, R-2 = 4.6 +/- 0.4 (R-circle dot); T-1 +/- 24 000, T-2 +/- 17 000 (K); photometric distance similar to 135 (pc).Öğe Absolute parameters of young stars: HX Velorum(Oxford Univ Press, 2019) Blackford, M. G.; Erdem, A.; Surgit, D.; Ozkardes, B.; Budding, E.; Butland, R.; Demircan, O.We present combined photometric and spectroscopic analyses of the southern multiple star HX Vel. High-resolution spectra of this system were taken at the University of Canterbury Mt. John Observatory in the years 2009-2015. Absolute parameters for HX Vel tend to confirm its young and near-main-sequence nature. We specify the main adopted parameters of the (non-eclipsing) close binary as follows: M-1 = 8.5 +/- 1.7, M-2 = 5.4 +/- 1.2, R-1 = 5.0 +/- 0.3, R-2 = 3.1 +/- 0.2, (circle dot); T-1 25 000 +/- 1300, T-2 20 000 +/- 2500 (K); systemic M-V -4.2 +/- 0.2. These parameters are sensitive to the low inclination, where we find a small disparity between the photometrically optimal 28 +/- 2 degrees and an adopted value of 26 degrees that gives better consistency with main-sequence stellar modelling. The relationship of HX Vel to the galactic cluster IC 2395 and OB association Vela OB1C is also considered, in the context of photometric parallaxes found for HX Vel and other cluster members.Öğe Absolute parameters of young stars: QZ Carinae(Oxford Univ Press, 2017) Walker, W. S. G.; Blackford, M.; Butland, R.; Budding, E.New high-resolution spectroscopy and BVR photometry together with literature data on the complex massive quaternary star QZ Car are collected and analysed. Absolute parameters are found as follows. System A: M-1 = 43 (+/- 3), M-2 = 19 (+3 -7), R-1 = 28 (+/- 2), R-2 = 6 (+/- 2), (circle dot); T-1 similar to 28 000, T-2 similar to 33 000 K; System B: M-1 = 30 (+/- 3), M-2 = 20 (+/- 3), R-1 = 10 (+/- 0.5), R-2 = 20 (+/- 1), (circle dot); T-1 similar to 36 000, T-2 similar to 30 000 K (model dependent temperatures). The wide system AB: Period = 49.5 (+/- 1) yr, Epochs, conjunction = 1984.8 (+/- 1), periastron = 2005.3 (+/- 3) yr, mean separation = 65 (+/- 3), (au); orbital inclination = 85 (+5 - 15) deg, photometric distance similar to 2700 (+/- 300) pc, age = 4 (+/- 1) Myr. Other new contributions concern: (a) analysis of the timing of minima differences (O - C) s for the eclipsing binary (System B); (b) the width of the eclipses, pointing to relatively large effects of radiation pressure; (c) inferences from the rotational widths of lines for both Systems A and B; and (d) implications for theoretical models of early-type stars. While feeling greater confidence on the quaternary's general parametrization, observational complications arising from strong wind interactions or other, unclear, causes still inhibit precision and call for continued multiwavelength observations. Our high-inclination value for the AB system helps to explain failures to resolve the wide binary in the previous years. The derived young age independently confirms membership of QZ Car to the open cluster Collinder 228.Öğe Absolute parameters of young stars: V454 Carinae(Oxford Univ Press, 2019) Butland, R. J.; Erdem, A.; Ozkardes, B.; Blackford, M. G.; Surgit, D.; Budding, E.; Demircan, O.We present combined photometric and spectroscopic analyses of the multiple star V454 Carinae. High-resolution spectra of the system were taken at the University of Canterbury Mt. John Observatory during the years 2008-18. These have been processed using generic and purpose-built software. New digital single lens reflex photometry of the system has also been collected and similarly analysed. Absolute parameters for the three main stars confirm V454 Car's young and near-Main-Sequence nature. We find: M-1 = 4.6 +/- 0.4, M-2 = 4.4 +/- 0.4, M-3 = 4.5 +/- 0.5, R-1 = 2.83 +/- 0.18, R-2 = 2.74 +/- 0.16, R-3 = 2.78 +/- 0.16 (circle dot); T-1 similar to 17 500, T-2 similar to 15 500, T-3 similar to 15 000 (K), age similar to 30 Myr, photometric distance similar to 500 (pc). The major component V454 Car A is the close binary identified by the HIPPARCOS satellite. This binary and component B appear to be in eccentric orbits about a common centre of gravity with a period of similar to 1900 d. Analysis of the radial velocity curves suggests that the mass of component B is greater than that of its visible member. Measured radial velocities of this visible star show irregularities with a time-scale of about a week. The galactic location, proper motions, and age of V454 Car support the runaway nature proposed by others, and the combined results are consistent with a dynamical ejection scenario from the Vela region of Gould's Belt relatively soon after the stars' formation.Öğe An investigation into exoplanet transits and uncertainties(Springer, 2017) Ji, Y.; Banks, T.; Budding, E.; Rhodes, M. D.A simple transit model is described along with tests of this model against published results for 4 exoplanet systems (Kepler-1, 2, 8, and 77). Data from the Kepler mission are used. The Markov Chain Monte Carlo (MCMC) method is applied to obtain realistic error estimates. Optimisation of limb darkening coefficients is subject to data quality. It is more likely for MCMC to derive an empirical limb darkening coefficient for light curves with S/N (signal to noise) above 15. Finally, the model is applied to Kepler data for 4 Kepler candidate systems (KOI 760.01, 767.01, 802.01, and 824.01) with previously unpublished results. Error estimates for these systems are obtained via the MCMC method.Öğe Analysis of ? Librae including Hipparcos astrometry(Blackwell Publishing, 2006) Bakis, V.; Budding, E.; Erdem, A.; Bakis, H.; Demircan, O.; Hadrava, P.New spectroscopy of the classical Algol system delta Lib, combined with high-quality optical and infrared photometry, provides the basis for a good understanding of the close binary system's main parameters. Detailed analysis of the photometry reveals the significant role of a third light source, pointing to the existence of a companion to the eclipsing system of mass similar to 1 M-circle dot. We review the methodology of applying high-accuracy positional information, available from the Hipparcos Intermediate Astrometric Data archive, to stars that may have such companions. Analysis of the astrometry of delta Lib also points to a third star similar to the one already identified by Worek from radial-velocity data, although with slightly revised parameters. O-C data do not contradict this, but their general precision (while confirming the close pair's Algol status) fails to allow a decision on the third orbit parameters: Worek's or revised ones. Taking the photometry, spectroscopy and astrometry together, however, the existence of a third star of comparable mass to the Sun, as a relatively close companion to the eclipsing binary (similar to 4 au), is confirmed.Öğe Analysis of Exoplanet Light Curves(Astronomical Soc Pacific, 2015) Erdem, A.; Budding, E.; Rhodes, M. D.; Puskullu, Q.; Soydugan, Faruk; Soydugan, Esin; Tuysuz, M.We have applied the close binary system analysis package WINFITTER to a variety of exoplanet transiting light curves taken both from the NASA Exoplanet Archive and our own groundbased observations. WINFITTER has parameter options for a realistic physical model, including gravity brightening and structural parameters derived from Kopal's applications of the relevant Radau equation, and it includes appropriate tests for determinacy and adequacy of its best fitting parameter sets. We discuss a number of issues related to empirical checking of models for stellar limb darkening, surface maculation, Doppler beaming, microvariability, and transit time variation (TTV) effects. The Radau coefficients used in the light curve modeling, in principle, allow structural models of the component stars to be tested.Öğe Analysis of selected Kepler Mission planetary light curves(Springer, 2014) Rhodes, M. D.; Budding, E.We have modified the graphical user interfaced close binary system analysis program CurveFit to the form WinKepler and applied it to 16 representative planetary candidate light curves found in the NASA Exoplanet Archive (NEA) at the Caltech website , with an aim to compare different analytical approaches. WinKepler has parameter options for a realistic physical model, including gravity-brightening and structural parameters derived from the relevant Radau equation. We tested our best-fitting parameter-sets for formal determinacy and adequacy. A primary aim is to compare our parameters with those listed in the NEA. Although there are trends of agreement, small differences in the main parameter values are found in some cases, and there may be some relative bias towards a 90(a similar to) value for the NEA inclinations. These are assessed against realistic error estimates. Photometric variability from causes other than planetary transits affects at least 6 of the data-sets studied; with small pulsational behaviour found in 3 of those. For the false positive KOI 4.01, we found that the eclipses could be modelled by a faint background classical Algol as effectively as by a transiting exoplanet. Our empirical checks of limb-darkening, in the cases of KOI 1.01 and 12.01, revealed that the assigned stellar temperatures are probably incorrect. For KOI 13.01, our empirical mass-ratio differs by about 7 % from that of Mislis and Hodgkin (Mon. Not. R. Astron. Soc. 422:1512, 2012), who neglected structural effects and higher order terms in the tidal distortion. Such detailed parameter evaluation, additional to the usual main geometric ones, provides an additional objective for this work.Öğe Analysis of the exoplanet containing system Kepler-13(Springer, 2018) Budding, E.; Puskullu, C.; Rhodes, M. D.We have applied the close binary system analysis program WINFITTER, with its physically detailed fitting function, to an intensive study of the complex multiple system Kepler-13 using photometry data from all 13 short cadence quarters downloaded from the NASA Exoplanet Archive (NEA) (http://exoplanetarchive.ipac.caltech.edu ). The data-point error of our normalized, phase-sequenced and binned (380 points per bin: 0.00025 phase interval) flux values, at 14 ppm, allows the model's specification for the mean reference flux level of the system to a precision better than 1 ppm. Our photometrically derived values for the mass and radius of KOI13.01 are 6.8 +/- 0.6 M-J and 1.44 +/- 0.04 R-J. The star has a radius of 1.67 +/- 0.05 R-circle dot. Our modelling sets the mean of the orbital inclination i at 94.35 +/- 0.14 degrees, with the star's mean precession angle phi(p) -49.1 +/- 5.0 degrees and obliquity theta(o) 67.9 +/- 3.0 degrees, though there are known ambiguities about the sense in which such angles are measured. Our findings did not confirm secular variation in the transit modelling parameters greater than their full correlated errors, as argued by previous authors, when each quarter's data was best-fitted with a determinable parameter set without prejudice. However, if we accept that most of the parameters remain the same for each transit, then we could confirm a small but steady diminution in the cosine of the orbital inclination over the 17 quarter timespan. This is accompanied by a slight increase of the star's precession angle less negative), but with no significant change in the obliquity of its spin axis. There are suggestions of a history of strong dynamical interaction with a highly distorted planet rotating in a 3:2 resonance with its revolution, together with a tidal lag of similar to 30 deg. The mean precessional period is derived to be about 1000 y, but at the present time the motion of the star's rotation axis appears to be supporting the gravitational torque, rather than providing the balance against it that would be expected over long periods of time. The planet has a small but detectable backwarming effect on the star, which helps to explain the difference in brightness just after transit and just before occultation eclipses. In assessing these findings it is recognized that sources of uncertainty remain, notably with possible inherent micropulsational effects, variations from other components of the multiple star, stellar activity, differential rotation and the neglect of higher order terms (than r(1)(5)) in the fitting function, where r(1) is the ratio of the radius of the star to the mean orbital separation of planet and host star.Öğe Analysis of the exoplanet containing system Kepler-91(Springer, 2016) Budding, E.; Puskullu, C.; Rhodes, M. D.; Demircan, O.; Erdem, A.We have applied the graphical user interfaced close binary system analysis program WINFITTER to an intensive study of Kepler-91 using all the available photometry from the NASA Exoplanet Archive (NEA) at the Caltech website: http://exoplanetarchive.ipac.caltech.edu. Our fitting function for the tidal distortion derives from the relevant Radau equation and includes terms up to the fifth power of the fractional radius. This results in a systematic improvement in the mass ratio estimation over that of Lillo-Box et al. (Astron. Astrophys. 562:A109, 2014a) and our derived value for the mass ratio is in close agreement with that inferred from recent high-resolution spectroscopic data. It is clear that the data analysis in terms of simply an eclipsing binary system is compromised by the presence of significant other causes of light variation, in particular non-radial pulsations. We apply a low-frequency filtering procedure to separate out some of this additional light variation. Whilst the derived eccentricity appears then reduced, an eccentric effect remains in the light curve. We consider how this may be maintained in spite of likely frictional effects operating over a long time. There are also indications that could be associated with Trojan or other period-resonant mass concentrations. Suggestions of a possible secular period variation are briefly discussed.Öğe Collaborative Studies of Southern Close Binary Systems(Astronomical Soc Pacific, 2015) Budding, E.; Blackford, M.; Butland, R.; Demircan, O.; Erdem, A.; Idaczyk, R.; Ozkardes, B.We present a few items from our southern eclipsing binary program, underway in recent years and involving observations at the Mt. John University Observatory and elsewhere in Australasia. Reduction and analysis have also been carried out at COMU (Turkey). Derived parameters allow interesting comparisons with other recent findings on binary stars, observational and theoretical.Öğe Cool Active Binaries Recently Studied in the CAAM Stellar Program(Astronomical Soc Pacific, 2010) Cicek, C.; Erdem, A.; Soydugan, Faruk; Dogru, D.; Ozkardes, B.; Erkan, N.; Budding, E.We summarize recent work on cool active stars in our programme. We carried out photometry at the canakkale Onsekiz Mart University (COMU) observatory, and high-resolution spectroscopy at Mt John University Observatory, as well as collecting data from other facilties. A combination of analysis methods, including our information limit optimization technique (ILOT) with physically realistic fitting functions, as well as other public-domain software packages, have been used to find reliable parameters. Stars in our recent programme include V1430 Aql, VI 034 Her, V340 Gem, SAO 62042, FI Cnc, V2075 Cyg, FG UMa and BM CVn. Light variations, sometimes over numerous consecutive cycles, were analysed. For AB Dor and CF Tuc, we compared broadband (B and V) maculation effects with emission features in the Ca II K and H-alpha lines. Broadband light curves typically show one or two outstanding maculae. These appear correlated with the main chromospheric activity sites ('faculae'), that occur at similar latitudes and with comparable size to the photometric umbrae, but sometimes with significant displacements in longitude. The possibility of large-scale bipolar surface structure is considered, keeping in mind solar analogies. Such optical work forms part of broader multiwavelength studies, involving X-ray and microwave observations, also mentioned.Öğe Discovery of new variable stars at the Canakkale Onsekiz Mart University Observatory(Astronomical Soc Pacific, 2007) Bakis, V.; Bakis, H.; Demircan, O.; Budding, E.; Erdem, A.; Cicek, C.We present the light curves of five variable stars discovered at the Canakkale Onsekiz Mart University Observatory. From the light curve shapes of the variables we see that GSC 4288 0186 and GSC 4019 3345 are detached, USNO 1500-00409928 is a W UMa-type eclipsing binary, while the others seem to be intrinsic variable stars. By using a 30-cm telescope equipped with an ST237 CCD camera dedicated for times of minima observations, we plan to perform systematic observations to discover new variable stars with the help of automatic data reduction techniques in the future.Öğe First Spectroscopic Study of the Southern Eclipsing Binary V454 Carina(Astronomical Soc Pacific, 2015) Ozkardes, B.; Erdem, A.; Surgit, D.; Butland, R.; Budding, E.We present preliminary results from the analysis of spectroscopic observations of the southern eclipsing binary star V454 Car (HIP 36682). High-resolution spectra of the system were taken at the Mt. John University Observatory in 2009, 2010, 2011, and 2014. Detailed examination of the spectra indicates that V454 Car is a triple system. Radial velocities of the components of the eclipsing pair were obtained. The orbital solution gave quite a large spectroscopic mass ratio of q(spec) = 0.93 +/- 0.05.Öğe Multisite, multiwavelength studies of the active cool binary CC Eri(2006) Budding, E.; Bembrick, C.; Carter, B.D.; Erkan, N.; Jardine, M.; Marsden, S.C.; Osten, R.New data acquired on the active, cool binary CC Eri ranged across the spectrum from Chandra X-ray to broadband photometry and microwave observations using the VLA and ATCA. Also, high-dispersion spectropolarimetry using the AAT enabled Zeeman-Doppler imaging to be performed. Our interpretations infer strong localised concentrations of the stellar magnetic field, manifested by surface activity and related large coronal plasma structures. Comprehensive matching of the modelling parameters awaits more detailed investigation. This brief interim review includes consideration of the ATCA data. Microwave radio emission is usually low level ('quiescent'), but occasionally flares of several mJy peak intensity are observed. We associate the emission, generally, with wave-like mechanisms, expanding through the outer atmosphere. Related characteristics of this emission are discussed. © Springer Science+Business Media B.V. 2006.Öğe Multiwavelength Observations of AB Doradus(Cambridge Univ Press, 2014) Slee, O. B.; Erkan, N.; Johnston-Hollitt, M.; Budding, E.We have observed the bright, magnetically active multiple star AB Doradus in a multiwavelength campaign centring around two large facility allocations in November 2006 and January, 2007. Our observations have covered at least three large flares. These flares were observed to produce significant hardening of the X-ray spectra during their very initial stages. We monitored flare-related effects using the Suzaku X-ray satellite and the Australia Telescope Compact Array (ATCA) at 3.6 and 6 cm. Observations at 11 and 21 cm were also included, but they were compromised by interference. Optical monitoring was also provided by broadband B and V photometry and some high-dispersion spectrograms. From this multiwavelength coverage we find that the observed flare effects can be mainly associated with a large active region near longitude zero. The second major X-ray and microwave flare of Jan 8, 2007 was observed with a favourable geometry that allowed its initial high-energy impulsive phase to be observed in the higher frequency range of Suzaku's XIS detectors. The fractional circular polarisation (Stokes V/I) was measured in the uv data for the complete runs, for 25 min integrations and, at 4.80 GHz, for 5 min integrations, using the radio data of Nov 21 2006 and Jan 08 2007. Most of the full data sets showed V/I fractions from AB Dor B that were significant at greater than the 3 sigma level. In several of the 5 min integrations at 4.80 and 8.64 GHz this fraction reached a significance level between 3 and 9 sigma. Lack of angular resolution prevented identification of these high V/I values with one or other of the two low-mass red-dwarf components of AB Dor B.Öğe Observation and analysis of RW Doradus(Csiro Publishing, 2007) Marino, B. F.; Walker, W. S. G.; Bembrick, C.; Budding, E.Photometry of the short-period (P similar to 0.285 d) low-mass (M-1 similar to 0.67, M-2 similar to 0.48 M-circle dot) W UMa-type eclipsing binary RW Dor, mainly involving a good series of observations in 1987-88, using standard B and V filters at the Auckland Observatory, is examined. Analysis via light curve fittings alone permits both transit (near main sequence) and occultation (W-type contact binary) solutions. Consideration of proximity or other effects on the relatively small number of measured radial velocities gives rise to a more detailed review of the alternatives, though the (W-type) configuration determined by Hilditch, Hill & Bell (1992) is still confirmed. Further implications of this configuration are examined, given an apparent general trend to period decrease (Delta P/P similar to 6 x 10(-11)), and some light curve asymmetry. This is consistent with the initially low-mass companion, Case-B scenario of Budding (1984). The evidence does suggest irregularity of the period variation however, and further detailed surveillance, including more spectroscopy, is desirable.
