Astron. Astrophys. Suppl. Ser. 134, 129-133

Photometry and spectroscopy of the central star of the Trifid nebula

L. Kohoutek¹ - P. Mayer² - R. Lorenz³

Send offprint request: P. Mayer

1 - Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany
2 - Astronomical Institute, Charles University, V Holesovickách 2, 180 00 Praha 8, Czech Republic
3 - Dr. Remeis-Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, Sternwartstraße 7, D-96049 Bamberg, Germany

Received December 12, 1997; accepted July 27, 1998

Abstract:

UBV photometry of the central star of the Trifid nebula - HD 164492, which has so far been suspected of photometric as well as of radial velocity variability - is presented. The results of our photometry do not confirm any variability. Moreover, based on new high resolution CCD spectra any radial velocity variability can be discarded. Photometry of several other members of the multiple stellar system is included; according to this photometry, the system is a physical one. Equivalent widths for the main component of HD 164492 are given. Positions measured on CCD exposures are presented too.

Key words: binaries: visual -- stars: early-type -- stars: HD 164492 -- ISM: Trifid nebula