We report the detection of the H i line at 21 cm in the direction of α Orionis (α Ori) with the Nançay Radiotelescope and with the Very Large Array. The observations confirm the previous detection of H i emission centred on α Ori, but additionally reveal for the first time a quasi‐stationary detached shell of neutral atomic hydrogen ∼4 arcmin in diameter (0.24 pc at a distance of 200 pc). The detached shell appears elongated in a direction opposite to the star’s space motion. A simple model shows that this detached atomic gas shell can result from the collision of the stellar wind from α Ori with the local interstellar medium (ISM). It implies that α Ori has been losing matter at a rate of ∼1.2 × 10−6 M⊙ yr−1 for the past 8 × 104 yr. In addition, we report the detection of atomic hydrogen associated with the far‐infrared arc located 6 arcmin north‐east of α Ori, which has been suggested to trace the bow shock resulting from the motion of the star through the ISM. We also report the detection by the Galaxy Evolution Explorer of a far‐ultraviolet counterpart to this arc.

Abstract. Recent hydrodynamical models (Winters et al. 2000b) allow the existence of pulsating, large velocity amplitude Asymptotic Giant Branch (AGB) stars with tenuous dusty circumstellar shells, which produce low mass-loss rates and simultaneously low wind velocities. The Semi-regular long-period variable L 2 Pup shows a broad SiO maser feature at 86 GHz (v = 1, J = 2−1), indicating an outward velocity of the material close to the stellar photosphere of at least 10 km s −1 , and narrow CO (J = 2−1) and (1−0) line profiles indicating an outflow velocity of the material in the circumstellar shell of only about 3 km s −1 . This can be explained in terms of our hydrodynamical models which provide large velocities in the shocked stellar atmosphere and low velocities of the circumstellar outflow.

Abstract.We have compiled the near infrared Point Source Catalogue (PSC) towards the Magellanic Clouds (MCs) extracted from the data obtained with the Deep Near Infrared Survey of the Southern Sky -DENIS • 00 00 ) for the Small Magellanic Cloud (SMC) at the epoch J2000. It contains about 1 300 000 sources towards the LMC and 300 000 sources towards the SMC each detected in at least 2 of the 3 photometric bands involved in the survey (I, J, K s ). 70% of the detected sources are true members of the Magellanic Clouds, respectively and consist mainly of red giants, asymptotic giant branch stars and super-giants. Send offprint requests to: M-R. CioniBased on observations collected at the European Southern Observatory.The Denis Point Source Catalogue towards the Magellanic clouds, data (Table 7) and quality ( The observations have all been made with the same instrument and the data have been calibrated and reduced uniformly. The catalogue provides a homogeneous set of photometric data.

Abstract. The H I line at 21 cm has been detected in the circumstellar shells of the two semi-regular variables, EP Aqr and Y CVn, with the Nançay Radio-Telescope (NRT). In both cases the line shape is composite and the emission is spatially extended compared to the NRT beam size (4 ). The total H I masses of the two envelopes are respectively ∼0.047 M and 0.044 M . For EP Aqr, we find three components: a narrow one centered on the star and spatially unresolved, and two broad, Gaussian components, offset w.r.t. the star and spatially extended. The narrow component traces the present wind from EP Aqr whereas the two others seem to trace one or several mass-loss episodes of long duration. For Y CVn, we find two components: a narrow, spatially very extended, feature, and a broad one, less extended. We argue that the second component traces the outflow and the first one, its interaction with the ISM. These observations show that the H I emission can be used not only to probe the mass loss history of long-period variables, but also to investigate the interaction between stellar outflows and the surrounding ISM.

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