71 Tauri (= BS 1394 = vB 141 = V777 Tau) is a rapidly rotating, F0 IV–V member of the Hyades cluster. It is the second brightest X-ray source in the cluster, after V471 Tauri, and an intensely bright coronal EUV source (Stern et al. 1995). It is a lunar occultation binary, but the secondary star (estimated by Peterson et al. 1981 to be a G4 V star in possibly a 53 day orbit) has never been seen...

Scintillation noise due to the Earth’s turbulent atmosphere can be a dominant noise source in high-precision astronomical photometry when observing bright targets from the ground. Here we describe the phenomenon of scintillation from its physical origins to its effect on photometry. We show that Young’s scintillation-noise approximation used by many astronomers tends to underestimate the median...

While it is apparent that many comets are active beyond the canonical distance of 3 AU, few surveys of cometary activity have been performed in this region previously. Such a survey enables a more accurate determination of the proportion of comets that exhibit little or no outgassing at these distances. Results are presented of CCD observations of comets in the region of 3 AU ≤ Rh ≤ 6 AU obtain...