Optical and near-IR observations of variable stars with AURELIE 

Abstract

Abstract. We report high and intermediate resolution spectroscopic observations of many emission line stars mainly observed with Aurélie at the 1.52 m OHP telescope in December 1990 and January 1995, with special attention to the Hα and 1 µm regions. The near-IR observations of the Be star γ Cas disclosed the presence of a very strong fluorescence Fe ii 1.00 µm emission, with intensity and profile similar to that of Pδ. Both have varied between 1990 and 1995. The Fe ii 1.00 µm line is also weakly present in emission in β Ori, and in the 1990 and 1995 spectra of the VV Cep star KQ Pup. The high resolution 1995 observations of the yellow hypergiant HR 8752 disclosed a broad [N ii] emission, and Hα with multiple components. The slow approaching of the KQ Pup system to periastron is marked by the large strengthening of the Hα emission between 1984 and 1995. Strong variation in Hα intensity was also found in the yellow symbiotic star AG Dra observed in quiescence and during its recent active phase. The red symbiotic star CH Cyg was especially interesting for the large profile variation of the Balmer lines on a daily time scale in January 1995. We detected expansion velocities of up to 2000 km s −1 . In December 1990 the yellow spectrum of CH Cyg displayed a broad He i 587 nm absorption, which turned to strong emission in 1995. We also report observations of π Aqr, R Aqr, EZ CMa, β CMi, and HD 200775.

Emission lines in the spectrum of the symbiotic star AG Draconis from 1997 to 2003

“…The possible double-peaked emission profile observed by Robinson et al (1994) on May 4, 1990, corresponds to Φ Meinunger = 0.455, Φ Bastian = 0.016 and Φ puls = 0.671. Viotti et al (1998) also report possible indication of a double-peaked structure in Hα in May 1992. They have not specified the date, but fixing it as May 16, 1992 yields Φ Meinunger = 0.796 ± 0.027, Φ Bastian = 0.979 ± 0.040, Φ puls = 0.762 ± 0.042.…”

“…It is known from earlier spectroscopic studies that intensities of the emission lines in the spectrum of AG Dra can vary significantly (Iijima et al 1987;Mikołajewska et al 1995;Tomov & Tomova 2002;Tomova & Tomov 1999;Viotti et al 1998). We are interested in the time scales of the variability, namely, are variations of the emission lines correlated with orbital motion, or with shorter periods of variability around 350-380 days, or are there no correlations at all.…”

“…They have not specified the date, but fixing it as May 16, 1992 yields Φ Meinunger = 0.796 ± 0.027, Φ Bastian = 0.979 ± 0.040, Φ puls = 0.762 ± 0.042. The Hα profile from January 16, 1995 in Viotti et al (1998) can also be considered as a "structured" one; this corresponds to the phases Φ Meinunger = 0.556, Φ Bastian = 0.554 and Φ puls = 0.506. Phase coverage of our 22 high-dispersion spectra is quite poor and not uniform.…”

“…When applying more data from the literature, the picture becomes even more confused. For example, Viotti et al (1998) measured the EW of the Hα line as low as 19.1 Å on December 27, 1990 (Φ Meinunger = 0.883, Φ Bastian = 0.642, Φ Galis,puls = 0.337, Φ Galis,orb = 0.411). Tomova & Tomov (1999) report the very high EW value of 184 Å on January 23, 1994, at quite similar phases, when the star was still in quiescence (Φ Meinunger = 0.911, Φ Bastian = 0.610, Φ Galis,puls = 0.500, Φ Galis,orb = 0.455).…”

A Study of π Aquarii during a Quasi‐normal Star Phase: Refined Fundamental Parameters and Evidence for Binarity

“…The profile shape was single-peaked from 1973 to 1989 (e.g., Slettebak & Reynolds 1978;Andrillat & Fehrenbach 1982). However, in 1989 it changed to a double-peaked profile, and only this shape was detected until 1995 (Hanuschik et al 1996;Viotti, Rossi, & Muratorio 1998). Characteristic H line profiles obtained by different studies during the active Be star phase are displayed in Figure 3.…”