Pt 1: a Halo symbiotic binary not related to the globular cluster NGC 6401.
Abstract
We present absolute 4000-9000 A spectrophotometry and astrometry of the emission line object Pt 1, originally discovered as a planetary nebula possibly associated with the Bulge globular cluster NGC 6401 and later discussed as a symbiotic star. The radial velocity (-350+/-10km/s), the distance (2.7+/-1.2kpc) and possibly also the metallicity of the late type giant all deny association of Pt 1 with NGC 6401. The extreme values derived both from absorption and emission features make Pt 1 the symbiotic star with the highest known radial velocity and strongly suggest that it belongs to the Halo population of the Galaxy. It is then seen projected against NGC 6401 and quite close to the galactic center by a mere coincidence. Our kinematic data on Pt 1 suggest an extremely eccentric galactocentric orbit with an orbital period of several 10^8^yr. The limited number of passages through the Bulge over the lifetime of the Galaxy supports the possibility that Pt 1 is a first generation Halo binary.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1994
- Bibcode:
- 1994A&A...292..501M
- Keywords:
-
- Emission Spectra;
- Galactic Halos;
- Globular Clusters;
- Infrared Astronomy;
- Infrared Spectra;
- Milky Way Galaxy;
- Symbiotic Stars;
- Visible Spectrum;
- Absorption Spectra;
- Astrometry;
- Distance;
- Galactic Bulge;
- Kinematics;
- Metallicity;
- Planetary Nebulae;
- Radial Velocity;
- Stellar Spectrophotometry;
- Astronomy;
- ASTROMETRY;
- BINARIES: SYMBIOTIC;
- STARS: EMISSION LINE;
- STARS: INDIVIDUAL: PT 1;
- PLANETARY NEBULAE: INDIVIDUAL: PT 1;
- GLOBULAR CLUSTERS: INDIVIDUAL: NGC 6401