The first complete orbital solution for the double-lined spectroscopic binary system γ 2 Velorum, obtained from measurements with the Sydney University Stellar Interferometer (SUSI), is presented. This system contains the closest example of a Wolf-Rayet star and the promise of full characterization of the basic properties of this exotic high-mass system has subjected it to intense study as an archetype for its class. In combination with the latest radial-velocity results, our orbital solution produces a distance of 336 +8 −7 pc, significantly more distant than the Hipparcos estimation. The ability to fully specify the orbital parameters has enabled us to significantly reduce uncertainties and our result is consistent with the Very Large Telescope Interferometer (VLTI) observational point, but not with their derived distance. Our new distance, which is an order of magnitude more precise than prior work, demands critical reassessment of all distance-dependent fundamental parameters of this important system. In particular, membership of the Vela OB2 association has been re-established, and the age and distance are also in good accord with the population of young stars reported by Pozzo et al. We determine the O-star primary component parameters to be M V (O) = −5.63 ± 0.10 mag, R(O) = 17 ± 2 R and M(O) = 28.5 ± 1.1 M . These values are consistent with calibrations found in the literature if a luminosity class of II-III is adopted. The parameters of the Wolf-Rayet (WR) component are M v (WR) = −4.33 ± 0.17 mag and M(WR) = 9.0 ± 0.6 M .

The binary star δ Sco (HD143275) underwent remarkable brightening in the visible in 2000, and continues to be irregularly variable. The system was observed with the Sydney University Stellar Interferometer (SUSI) in 1999, 2000, 2001, 2006 and 2007. The 1999 observations were consistent with predictions based on the previously published orbital elements. The subsequent observations can only be explained by assuming that an optically bright emission region with an angular size of ≳2 ± 1 mas formed around the primary in 2000. By 2006/2007 the size of this region grew to an estimated ≳4 mas. We have determined a consistent set of orbital elements by simultaneously fitting all the published interferometric and spectroscopic data as well as the SUSI data reported here. The resulting elements and the brightness ratio for the system measured prior to the outburst in 2000 have been used to estimate the masses of the components. We find MA= 15 ± 7 M⊙ and MB= 8.0 ± 3.6 M⊙. The dynamical parallax is estimated to be 7.03 ± 0.15 mas, which is in good agreement with the revised Hipparcos parallax.

Objectives: To examine planning age of the athletic retirement of elite athletes in the United Kingdom, short-term athletes' plans in terms of a balance between sports and other activities, and long-term athletes' plans in regard to their activities after sports career termination. Design and Methods: Participants were 561 elite-level athletes (mean age = 26.0 years) who completed a self-administered postal survey. A total of 37 individual and team sports were represented. Results: One-way analysis of variance procedures indicated that the age at which participants planned on retiring from sport varied significantly across sports, among male and female athletes, and among able and disabled athletes. A series of chi-square procedures revealed significant differences in the short-term plans of athletes in terms of increasing training, plans to start education and plans to find a job over the next twelve months.Conclusions: These appears to be an unwillingness among younger athletes and those who perceive themselves to have a significant amount of time before they retire to develop concrete plans about their future career prior to their retirement. It is recommended that further research be conducted in order to assess the career development needs of elite athletes across Europe.

We have used the Sydney University Stellar Interferometer to measure the angular diameter of α Cir. This is the first detailed interferometric study of a rapidly oscillating A (roAp) star, α Cir being the brightest member of its class. We used the new and more accurate Hipparcos parallax to determine the radius to be 1.967 ± 0.066 R⊙. We have constrained the bolometric flux from calibrated spectra to determine an effective temperature of 7420 ± 170 K. This is the first direct determination of the temperature of an roAp star. Our temperature is at the low end of previous estimates, which span over 1000 K and were based on either photometric indices or spectroscopic methods. In addition, we have analysed two high‐quality spectra of α Cir, obtained at different rotational phases and we find evidence for the presence of spots. In both spectra we find nearly solar abundances of C, O, Si, Ca and Fe, high abundance of Cr and Mn, while Co, Y, Nd and Eu are overabundant by about 1 dex. The results reported here provide important observational constraints for future studies of the atmospheric structure and pulsation of α Cir.

We have used the Sydney University Stellar Interferometer to measure the angular diameter of β Hydri. This star is a nearby G2 subgiant the mean density of which was recently measured with high precision using asteroseismology. We determine the radius and effective temperature of the star to be 1.814 ± 0.017 R (0.9 per cent) and 5872 ± 44 K (0.7 per cent) respectively. By combining the radius with the mean density, as estimated from asteroseismology, we make a direct estimate of the stellar mass. We find a value of 1.07 ± 0.03 M (2.8 per cent), which agrees with published estimates based on fitting in the Hertzsprung-Russell diagram, but has much higher precision. These results place valuable constraints on theoretical models of β Hyi and its oscillation frequencies.