Optical and near-IR observations of variable stars with AURELIE ^*

¹ Istituto di Astrofisica Spaziale, CNR, Area di Ricerca Tor Vergata, Via del Fosso del Cavaliere, 00133 Roma, Italy
² Istituto Astronomico, Università La Sapienza, Via G.M. Lancisi 29, 00161 Roma, Italy
³ Observatoire de Marseille, 2 place Le Verrier, 13248 Marseille Cedex 04, France

Send offprint request to: R. Viotti

Received: 18 February 1997
Accepted: 7 August 1997

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.