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We have observed 103 bright Be stars in the near infrared up to 10500 A with a dispersion of 230 and 50 A mm-1. The observations were performed with a Reticon (1024 diodes) attached to the ROUCAS spectrograph at the 193 cm telescope of the Haute Provence Observatory.
In this spectral range, the Be stars are characterized by the lines of HI (Paschen series), 0I(7772-74-75, 8446 A), CaII(8542, 8662, 8498 A), FeII(7712, 9997 A) and NI(8686-83-80, 8719-12-03, 8629 A).
On our spectra, the CaII triplet is always blended with P13, P15, P16, and only the enhancement of these lines permits to conclude to the CaII presence. The 0I 8446 A is perturbed by the Paschen lines P17 and P18 (low dispersion spectra) and P18 (high dispersion spectra). The NI 8686-83-80 A lines also perturb the P13 profile.
Nova Vul 1984 n°2 has been again observed at Observatoire de Haute-Provence in the autumn of 1985, i.e. 270–295 days after maximum. It was then in the nebular phase. The spectra cover the blue-violet and the near infrared regions. Over 50 lines and blends have been identified and are given in Table 2. No clear pattern is observed in the emission bands of a width of about 1450 km/sec. The most conspicuous features observed are the forbidden NeIII and NeV lines. The infrared region is dominated by a very strong He I 1083nm emission.
During the triennium under review, Commission 29 has sponsored or cosponsored the following IAU meetings: Symposium 102, “Solar and Stellar Magnetic Fields,” Zurich, Switzerland, August 1982; Symposium 108, “Structure and Evolution of the Magellanic Clouds,” Tübingen, FRG, September 1983; Symposium 111, “Calibration of Fundamental Stellar Quantities,” Como, Italy, May 1984; and Colloquium 82, “Cepheids: Observation and Theory,” Toronto, Canada, May-June 1984. Commission 29 has also supported or sponsored several IAU meetings proposed for 1985 and 1986. They include “Luminous Stars and Associations in Galaxies,” Porto Heli, Greece, May 1985; “Upper Main Sequence Stars with Anomalous Abundances,” Crimea, USSR, May 1985; “Astrochemistry,” Goa, India, December 1985; “Hydrogen Deficient Stars and Related Objects,” Bangalore, India, December 1985; “Circumstellar Matter,” Heidelberg, FRG, June 1986; and “Be Stars,” Boulder, USA, August 1986.
The observations reported here have been obtained with the ESO Reticon system attached to the Boller and Chivens spectrograph at the 3.6 m telescope. The reciprocal dispersion was 228 A mm−1 with a useful spectral range extending from 5800 A to 11000 A. The slit was 200 µm wide which corresponds to 1.4 arcsec on the sky and to about 33.5 µm(∼ 7.6 A) in the plane of the detector. Sky substraction was performed by means of observations at 93 arcsec. East and West of the object. The correction for atmospheric extinction was based on a mean extinction curve of La Silla (Tug, 1977). As a consequence the strongest atmospheric bands are still present on the final spectra. The data were also corrected for the instrument sensitivity response by using calibrated stars selected from Breger's catalog (1976). As these reference data are from filter photometry, they are not well suited to the resolution of our spectra, at least in some regions. This problem can be significant, as clearly illustrated by Johnson (1980).
November 27, 1980, we had the opportunity to make near infrared observations of a few WR stars of the Magellanic Clouds with the ESO reticon system attached to the Boller and Chivens spectrograph at the 3.6 m telescope. The observing conditions as well as the reduction procedure have been described in another paper of this symposium (Vreux et al., 1982). We will immediately show how the near infra-red can be useful to improve our knowledge of some WR stars.
Relatively few spectra of symbiotic stars have been recently published in the photographic infrared. We have observed six objects during the period 1962-1977 with a grating spectrograph attached to the newtonian focus of the 120-cm telescope at Observatoire de Haute Provence. The reciprocal dispersion is 230 A.mm-1 and the region 5800 to 8800 A has been covered using hypersensitized IN plates. The minimum equivalent width for an emission line to be seen is about 0.5 A. The spectra are displayed on plates I and II. We now briefly review the main spectral characteristics.
Since the time of I.A.U. Colloquium n° 70, new data have been obtained in the infrared, far less however than in the ultraviolet or in the visible. Few line spectra have been recorded but numerous results have been published in the field of spectrometry of the continuum. It is however neither easy nor very useful to report on the infrared wavelength range alone, and therefore we shall consider when appropriate other spectral regions in this review. After all, the astrophysicist nowadays has the advantage to seek for information in a spectrum which encompasses a fantastic frequency range of about 10 dex, from ν = 108s−1 up to ν = 1018s−1. This means that a contemporary astronomer will have to become familiar with a somewhat larger span of phenomena than with the rather narrow one he has been accustomed to for the last 40 or 50 years.
Among the 0 stars, Conti and Leep (1974) define the Oe class as those stars showing emission in the hydrogen lines but without emission in N III or 4686 He II.
In the blue-red region, aside from the presence of Lambda 4542 in absorption, the overall appearance is similar to Be stars. So far no Oe star has been observed until 1.1 μ: the aim of this paper is to fill this gap. We present observations of Oe stars in the near infra-red region as well as new observations of Hα profiles.
New visible and ultraviolet spectra of the peculiar emission line star HD 51585 are described. Interstellar lines and the λ 2200 feature are rather weak. A colour excess E(B-V) = 0.33 is derived. The extinction curve resembles the one obtained from LMC stars.
In the spectral range λλ5800-8750, HBV 475 shows important spectral variations between 1969 and 1974. Sometimes the “hot component” spectrum dominates (many emission lines), sometimes the “cool component” is preponderent (many molecular absorption Ti0 bands) (Andrillat 1973 – Andrillat, Houziaux 1976).
On August 4 1974, June 6 1975 and August 9 1981, we have extended the observations up to l.lμ (fig.l) (Haute Provence Observatory 193 Telescope – Spectro ROUCAS + Image tube – dispersion 230 A.mm-1).
Few studies concern the H alpha profile of the Be stars and it is difficult to do a fine analysis of the line structure, and of its variations from the results obtained with different resolutions and accuracies.
Then, it was useful to apply modern technics for the observation of this line to get an homogeneous material, sensitive enough to show fast variations of the order of few minutes because an accurate photometry is available using linear response receivers.
High resolution profiles of the Hα line are derived for about thirty Be stars and several bright stars by means of the anological television system. The profiles obtained with this method fairly agree with the theoretical ones (a Lyrae).
The λ 10124 He II line has been found to be a measurable emission in three stars. Our new data are compared to theoretical predictions. The λ 10830 He I line is observed in emission in 74% of the 05–08 supergiants but only seen in 29 % of the dwarfs, all of the latter exhibiting some “pecularities” i.e. classified as Oef, Oe, ON or On. An envelope with a sufficient amount of material seems to be a favorable condition to get the λ 10830 line in emission. However the mechanism leading to the observed emission is temperature dependent as well.
The aim of this paper is to report quite preliminary results obtained with a new multichannel detector put into operation at the Haute Provence Observatory. The observations have been made at the Cassegrain focus of the 1.93 m. The dispersion of the spectrograph was 17 Å. mm−1 at Hα and the slit was 300μ wide. The detector was a cooled SIT TV camera tube commercially available under the name of “Nocticon”. Details on the observing technique have been given elsewhere (Adrianzyk and al., 1978). We will only point out that all the wavelengths are recorded simultaneously : this recording technique is different from the scanning technique the result of which have been recently reviewed by Lacy (1977).
M2-9 is not a bona fide planetary, nor simply a star: it most probably is a planetary nebula in the formative stages. High densities, the presence of , Fell and [Fell] emission lines, and prominent infrared continua are characteristic of such objects. There is a striking progression of their spectra from B[e] stars such as HD45677 to M2-9 itself; Merrill's class of objects intermediate between Be stars and planetary nebulae is represented e.g. by MWC 645, HD 51585, V 1016 Cygni, HM Sagittae, and MIVC 349. Remarkable similarities exist between the spectra of the latter objects and that of M2-9, especially in the recently covered region between 8000 and 11000 Å which is rich in emission lines of the Paschen series, of Hel, 01, [SIII], Fell and [Fell] (Andrillat and Swings, 1977, in preparation).
230 Å mm-1 spectra of 30 stars of T Tauri or related type were obtained in the 8000-11000 Å region using a grating spectrograph equipped with an S-1 photocathode image-tube. In addition a few T Tauri stars were observed at the same dispersion in the 6200-8800 Å region on IN plate. A preliminary qualitative analysis of the observations leads to possible correlations between the intensities of emissions of the Ca II triplet, Paschen series and He I 10830 Å, and the spectral type, K-L color index of the star, or the [0 I] and Fe II intensities in the visible spectrum.
An image-tube Cassegrain spectrograph, equipped with an S-1 photocathode enabled us to obtain infrared spectra of peculiar emission-line objects, as V 1016 Cyg, HBV 475, HD 51585, HD 45677, XX Oph and CI Cyg. Many of these objects display emission lines of H I, He I, He II, O I, N I, Ca II [S II] [S III], [Fe II]. The line intensities can be used together with data from other parts of the spectrum to determine relative abundances of these ions in the shells of these objects, which may be at a critical phase of their evolution.