A dwarf nova HV Vir was observed photometrically for eight nights during the outburst in 1992 April -May. The star showed two distinct types of periodic variation: (1) 82.20-min (0.05708 d) double-humped variation with decaying amplitudes during the early stage of the outburst, and (2) 83.80-min (0.05820 d) superhumps in later stages. We attributed the former to "early superhumps", which are only seen in the earliest stage of WZ Sge-type outbursts. The superhump period and evolution of the superhumps, together with general characteristics of the light curve, make HV Vir a typical WZ Sge-type dwarf nova. HV Vir also showed a large increase of the superhump period during the superoutburst. Upon the recognition of the WZ Sge-type nature of an object previously considered as a nova, we present a comprehensive list of candidates for WZ Sge-type dwarf novae, and related systems.

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In an attempt to carry out a systematic study on the behavior of the photospheric abundances of Li, C, and O (along with Fe) for Hyades main-sequence stars in the T eff range of 5000-7000 K, we conducted an extensive spectrum-synthesis analysis applied to four spectral regions (comprising lines of Fe-group elements, Li I 6708 line, C I 7111-7119 lines, and O I 6156-8 lines), based on the high-dispersion spectra of 68 selected F-G type stars belonging to this cluster. The abundances of C and O turned out to be fairly uniform in a marginally supersolar level, such as like the case of Fe: h[C=H]i = +0.15 ( = 0.08), h[O=H]i = +0.22 ( = 0.14), and h[Fe=H]i = +0.11 ( = 0.08), suggesting that the primordial abundances are almost retained for these elements. Strictly, however, they show a slightly increasing trend with a decrease in T eff (typically on the order of 10 4 dex K 1 ); while this might be due to an improper choice of atmospheric parameters, we found it difficult to give a quantitatively reasonable explanation. Regarding Li, we confirmed the well-known T eff -dependent trend in the Li abundance reported so far (a conspicuous Li-trough at 6300 K . T eff . 6700 K and a progressive decrease toward a lower T eff at T eff . 6000 K), which means that the surface Li of Hyades stars is essentially controlled only by T eff ; other parameters, such as the rotational velocity, are almost irrelevant.

We report a newly developed spectropolarimeter with a low-dispersion resolution (R \ 40È 200) and a wide coverage in wavelength (400È900 nm). It is mainly used along with the 0.91 m telescope at the Dodaira Observatory of the National Astronomical Observatory, Japan. This instrument and the related reduction software are described brieÑy. The present polarimetric accuracy (rms) is estimated to be [(P/ 50)2 ] (0.05)2]1@2%, where P is the linear polarization degree in percent. The spectropolarimeter has the advantage of being most useful in the polarimetric studies of both the continuum and the strong emission and/or absorption lines. It is mainly used for the short-or long-term monitoring of variable circumstellar polarization and of polarization in comets, and for studies on interstellar polarization.

We present results from simultaneous multisite high-resolution spectroscopic and photometric observations of f Oph (HD 149757) taken in 1993 May. Our spectroscopic data include about 100 hr of continuous monitoring of the star.The line-proÐle variations of He I j6678, which are characterized by features traveling from blue to red, are well reproduced by two large-amplitude sinusoids and other sinusoids with smaller amplitudes.