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HR 1129 is a 4.8-mag star in the constellation Camelopardus, strangely (in view of its brightness) lacking a constellation designation. It has long been known to exhibit a composite spectrum consisting of a late-type primary and an early-type secondary. The radial velocity of the primary is easily measured, and was announced as variable nearly 100 years ago. A preliminary orbit with a period of 6150 d was given for it by one of the present authors in 1990; our new value is 6124 ± 3 d. The system has been resolved by speckle interferometry, but has not been measured systematically by that technique. The spectrum of the primary is found to be very similar to that of a Aqr (G2 Ib), although the parallax shows HR 1129 to be somewhat less luminous. The secondary spectrum has been isolated by subtraction and has proved to be that of a B7 star that is somewhat above the main sequence and may itself already be a giant. We present a comprehensive discussion of the spectra of both stars, and deduce that the system is considerably reddened: E(B - V) ∼ 0.30, A V Ā 0.9 mag. By incorporating 25 measurements of the radial velocity of the secondary, we calculate a double-lined orbit solution which gives the mass ratio for the components as 1.109 ± 0.022; we determine individual masses of 4.8-5.2 M ⊙ (primary) and 4.3-4.7 M ⊙ (secondary). The orbit is viewed at an inclination of ∼ 87°, but there are no eclipses. However, around the phases of conjunction the Mg II doublet near λ2800 A, as seen in IUE spectra, exhibits evidence of two circumstellar absorption systems, which we interpret as a wind from the cool giant and a static shell around it. Substantial 100-μm emission recorded by IRAS points to the presence of warm circumbinary dust enveloping the system, and is likely to have originated in the stellar wind.

The colliding-wind binary system WR140 (HD193793, WC7pd+O4-5, P=7.94 yr) was monitored in the ultraviolet by IUE from 1979 to 1994 in 35 short-wavelength high-resolution spectra. An absorption-line radial-velocity solution is obtained from the photospheric lines of the O component, by comparison with a single O star. The resulting orbital parameters, e=0.87 +/- 0.05, w=31 degrees +/- 9 degrees and Ko star=25 +/- 15 km s(-1), confirm the large eccentricity of the orbit, within the uncertainties of previous optical studies. This brings the weighted mean UV-optical eccentricity to e=0.85 +/- 0.04. Occultation of the O-star light by the WC wind and the WC+O colliding-wind region results into orbital modulation of the P-Cygni profiles of the C II, CIV and Si IV resonance lines. Near periastron passage, the absorption troughs of those resonance-line profiles increase abruptly in strength and width, followed by a gradual decrease. In particular, near periastron the blue black-edges of the P-Cygni absorption troughs shift to larger out ow velocities. We discuss that the apparently larger wind velocity and velocity dispersion observed at periastron could be explained by four phenomena: (i) geometrical resonance-line eclipse effects being the main cause of the observed UV spectral variability, enhanced by sightline crossing of the turbulent wind-wind collision zone; (ii) the possibility of an orbital-plane enhanced WC7 stellar wind; (iii) possible common-envelope acceleration by the combined WC and O stellar radiation fields; and (iv) possible enhanced radiatively driven mass loss due to tidal stresses, focused along the orbiting line of centers.

An analysis of the Hipparcos photometry of HD 115071 shows that it is an ellipsoidal variable with a period of 2.73126 days, twice that suggested previously. Modelling the light curve combined with the available radial velocities suggests that the more massive, hotter component is smaller and less luminous than the cooler component, which is probably filling its Roche lobe. The likely age of the system indicates that it is a MS + MS blue straggler, created by Case A mass exchange.

A detailed abundance analysis of the bright A-type star {3 Crt is presented. It is found that most of the abundances are essentially solar, indicating that the star is not a hot Am star. The only prominent anomalies are an under abundance of AI and overabundances of S, Sr and Ba. The barium overabundance is the most prominent and has important implications for the past history of this supposed binary system. The presence of the ROSAT-discovered white dwarf companion could indicate that the A-type star may have accreted material from the white dwarf progenitor. There are indications in the literature that the system is a relatively short -period binary. However, the radial velocity measurements presented in this paper show no apparent velocity changes, and do not support this hypothesis. It may be that the system is a wide long-period binary, or not even physically associated. Additional radial velocity measurements are required to investigate the orbit of this

New measurements of radial velocities from high-resolution IUE spectra of the massive X-ray binary HD 153919 give a velocity amplitude that is markedly smaller than that found in earlier studies, namely 5 km s −1 , compared with previous values of around 20 km s −1 . If such measurements relate to orbital motion, then the inferred component masses may need considerable revision to a more massive O star and/or a less massive compact companion. Alternative mechanisms to generate the velocity variations may need to be invoked

The system IK Peg has been known to be a binary for over 60 years but the secondary has never been identified. The detection of this system in the British Wide Field Camera All-Sky Survey in the EUV has enabled the secondary to be positively identified as a white dwarf. Fits to EUV survey data, the first IUE spectrum, and archival X-ray data indicate that the system contains a high-mass (∼ 1 M ○ .) white dwarf and that it is very close to edge-on. The evolutionary status of this system is discussed; it is shown to be the result of a common-envelope phase, and it is expected to evolve into a Type I supernova or a cataclysmic variable

The role of IUE in the determination of orbital elements of massive stars is reviewed, emphasising the complementary value of ultraviolet observations when combined with archival optical data. Results on eight systems are described and the potential of the IUE archive for radial velocity work in general is advocated.

A new radial velocity study has been made of the highly eccentric, early-type binary BD -1° 1004 using spectra from the Kavalur Observatory. All available archival material has also been reexamined. An attempt has been made to correct for line ‘dragging’ by the secondary spectrum to improve the fit of the observed data to the orbital solutions. It is found that an earlier suggestion of apsidal regression is still possible although ω is probably constant within the errors. There remain problems and inconsistencies with other orbital elements, in particular K1 and γ

A brief history of The Observatory Magazine is presented in the context of a review of the procedures and practices of the Editors over the last 125 years, so far as is known from the available archives. In an age of increasing emphasis on electronic communication, the future prospects for the Magazine may not be especially rosy.

We present the first orbital elements for the massive close binary, HD 115071, a double-lined spectroscopic binary in a circular orbit with a period of 2.73135 +/- 0.00003 days. The orbital semiamplitudes indicate a mass ratio of M_2/M_1 = 0.58 +/- 0.02 and yet the stars have similar luminosities. We used a Doppler tomography algorithm to reconstruct the individual component optical spectra, and we applied well known criteria to arrive at classifications of O9.5 V and B0.2 III for the primary and secondary, respectively. We present models of the Hipparcos light curve of the ellipsoidal variations caused by the tidal distortion of the secondary, and the best fit model for a Roche-filling secondary occurs for an inclination of i = 48.7 +/- 2.1 degrees. The resulting masses are 11.6 +/- 1.1 and 6.7 +/- 0.7 solar masses for the primary and secondary, respectively, so that both stars are very overluminous for their mass. The system is one of only a few known semi-detached, Algol-type binaries that contain O-stars. We suggest that the binary has recently emerged from extensive mass transfer (possibly through a delayed contact and common envelope process)., Submitted to ApJ

Radial velocity measurements on high-resolution spectra of X Persei from the IUE archive show that there is no variation above the level of a few km/s and thus no need for a massive unseen component in the system

A periodogram analysis of the radial velocities and absorption line strengths from IUE spectra of HD 50896 show evidence of the 3.766 day period usually associated with this star. The dominant line variations occur on time scales of ~ 1 day but may be interpreted as higher order harmonics of the 3.766 day period.

Ultraviolet high-resolution SWP images of the binary system WR140 (HD 193793, WC7+O4-5) were taken with IUE over the period 1979 – 1993. This poster presents a radial-velocity study of the absorption lines, attributed to the O-type component, applying the infrared period of P = 2900 days.

Using a simple absorption line model the phase dependent effects of ‘wind eclipses’ have been studied for the N IV 1718A line in the WN4+05 binary, HD 90657. The varying strength of the absorption, as measured by the equivalent width, has been compared with the model for a range of wind parameters and assumptions. It is found that the fraction of absorbing atoms drops quickly, to the first or second power of the radius, and that a significant fraction persists beyond 60 R∩.

Spectre a haute resolution de Mira Ceti obtenu par l'IUE le 7 juillet 1983. Les resultats confirment la presence de raies d'emission larges, et on ne detecte aucune raie d'emission etroite

Coude spectra of Nova Cygni 1975 have been compared with LTE synthetic spectra and abundances derived for carbon, nitrogen, and oxygen. It was found that while carbon is not enhanced over the solar value, nitrogen and oxygen are substantially over-abundant by factors of at least 30 and 10, respectively. These results can be compared with analyses performed on the nebular spectrum.

A report on the initial performance of the IUE satellite, launched in January, 1978, is given. Attention is given to optical performance, camera performance, background corrections, photometric performance, and data reduction. Samples of high-dispersion and low-dispersion spectra are shown. A remaining problem of proper separation of high dispersion orders in data reduction is discussed.

RZ Gru est confirmee comme variable cataclysmique. Son spectre UV suggere qu'elle appartient a la sous-classe UX UMa dans laquelle un disque optiquement epais est maintenu a l'etat eruptif. Une photometrie optique et UV coordonnee montre des changements d'environ une magnitude sur une echelle de quelques mois en plus de variation plus faible sur une echelle de minutes, mais aucune eruption importante de type nova naine

Initial IUE observations of four cool stars are reported. Observed fluxes and surface fluxes are given for several UV emission lines in the spectral range 1175-2000 A, obtained at low and high dispersion with the short-wavelength spectrograph and camera. These lines are formed in the outer atmospheres of these stars, in regions presumably analogous to the solar chromosphere and transition region. The surface fluxes in the lines increase along the sequence: quiet sun, Epsilon Eri, Lambda And, Alpha Aur, and HR1099. The 2.8-d RS CVn-type binary HR1099, observed on 1 March 1978 near the end of a major flaring episode, has line surface fluxes roughly 100 times that of the quiet sun, similar to those seen in solar flares. Line profiles and flux ratios in multiplets for Capella are presented, and comments given on the opacity of the lines and on a tendency of line width to increase with temperature of formation.

It is a great pleasure for me to attend this meeting to commemorate the hundredth aniversary of the Vienna Observatory, particularly so since I bring with me the greetings from the Royal Greenwich Observatory where we have also been celebrating the anniversary of our founding by King Charles II in 1675. Unfortunately, my aquaintance with the metallic line A stars is a mere seven years old and I feel somewhat presumptuous in giving a review of what is mainly your (the audience's) work. I have decided, therefore, to refer you to Conti's (1970) splendid and comprehensive account together with Preston's (1974) recent updating for the full story, and to content myself with some personal reflections on the state of observational work on the Am stars. This talk will doubtless reveal some of my muddled thinking and misconceptions and I trust you will not let me leave this conference with an incorrect picture of the work you are really doing on this interesting subgroup of peculiar stars.

During the commissioning phase of IUE observations were made of a selection of hot stars: the white dwarf HZ43, the hot subdwarf BD + 75°325, the nucleus of the planetary nebula NGC6826, the dwarf nova SS Cygni, and the peculiar object η Carinae. The observations were made in the low dispersion mode and the data have been reduced using a preliminary calibration. The results are presented and discussed for each object.

SummaryThe orbital elements of the SB2 λ Vir have been redetermined and the earlier period of 206 days found to be correct. Both stars have been classified as Am although they exhibit rather different ve.sin i's. An abundance analysis confirms the similarity in metallicity of the two components.

The case for use of automated abundance analysis procedures is examined and the progress made in that direction is reviewed. A program for the automatic measurement of equivalent widths is now operational and giving successful results for sharp lined A stars. Results for the Am star 88 Tauri, which exhibits significant rotational broadening, differ from previously published data and suggest that the older high dispersion measures suffer more from the effects of a rotationally depressed apparent continuum. Abundances are derived for 88 Tauri through computer analysis based on the differential curve of growth. (auth)

Although clearly a peculiar object (Anger 1933), HD 45166 has been the subject of remarkably few published optical studies. Heap & Aller (1978, HA) discuss its optical spectrum and give evidence that the object is a binary system comprising a B8v star and a hotter WR-like object, denoted qWR by van Blerkom (1978). This paper presents the first UV observations of the system obtained with IUE at the epochs listed in Table 1. These new data show drastic line (but not apparently continuum) variations with epoch, which cast doubt on the WR-connection, although herein we still adopt the notation “qWR”.

We have obtained low resolution UV spectrophotometry of the WN-C star HD 62910 in both the SWP (λλ1150–2000) and LWR (λλ1850–3250) IUE spectrographs, and also for HD 117688, WN6, used for comparison. The UV spectrum of HD 62910 is shown in Fig 1 and is seen to be dominated by many strong emission lines, which by comparison with the IUE spectra of other galactic WR stars (Nussbaumer et al. 1981) is found to reflect a predominantly WN-type spectrum, but in addition, weaker features characteristic of WC spectra are also seen, particularly in the LWR wavelength range. In Table 1 we list the principal observed WN and WC features in HD 62910. A comparison of the relative strengths of the WN emissions with those observed in various WN subtypes (Nussbaumer et al. 1981) and with our spectra of HD 117688 confirms the subtype of HD 62910 as WN6 as inferred in the visible (Smith 1968, Van der Hucht et al. 1981).

It is still a matter for some debate as to how far the most massive stars ever get towards the right-hand side of the HR diagram during the course of their evolution. The apparent absence of very luminous red stars suggests either that stars never reach this region at all, or that if they do, their sojourn there is very brief indeed. If the latter is the case, one might expect to see an increase in mass-loss activity with luminosity among the brightest stars that we actually do see - the cool galactic hypergiants. An attempt has been made to search for one of the signatures of mass-loss - thermal reemission from ejected dust - using recently released data from the InfraRed Astronomical Satellite (IRAS).

The recent study by Caillault et al. (1985) has shown the emission-line star AS 431 (= WR 147) to be a strong X-ray source and moderately strong radio emitter. Combining optical, near-infrared and radio data, they deduced that its mass loss rate was ∼ 4 × 10−4 M⊙yr−1, an order of magnitude greater than is normal for WR stars. They also suggested that it would show up in the IRAS survey and that such data would help to elucidate whether its extreme reddening had a significant circumstellar component. To investigate this possibility and to study the general properties of the object, we have raided the IRAS Point Source Catalogue.

High-resolution IUE spectroscopy of the low-mass qWR star HD 45166, obtained at several epochs during 1980-1988, reveals a complex pattern of variability in its stellar wind emission lines, P Cygni profiles, and highly ionized photospheric absorption spectrum. The most intensive observations, obtained during a 36 hr continuous run in February 1988, show the presence of discrete absorption components (DACs) in the C IV 1550 resonance doublet. These DACs can blend to give the appearance of a well-developed P Cygni absorption profile seen at some other times, roughly doubling the column density of the ground state C(3+) ions in the wind. In the 1988 spectra, two principal features are seen, at about -950 km/s and -750 km/s, with column densities of about 14.0 and 14.7 dex/sq cm, respectively. Both features migrate in velocity with accelerations of about 140 cm/sq sec, implying a recurrence time scale of about 1.6 days and a lifetime of about 3 days for the DACs. A striking characteristic of the acceleration is its slowness. The pattern of DAC variability in HD 45166 is similar to that found for O-type stars and provides further evidence that the DACs are not mass-conserving features but rather that a given feature is formed by different material at different times. It is concluded that the C IV DAC variability observed in HD 45166 results from structural changes in the wind arising from radiative instabilities.