Home     To Survive in the Universe    
Services
    Why to Inhabit     Top Contributors     Astro Photo     The Collection     Forum     Blog New!     FAQ     Login  
→ Adopt this star  

HD 158921


Contents

Images

Upload your image

DSS Images   Other Images


Related articles

A Dozen New γ Doradus Stars
We use new high-dispersion spectroscopic and precise photometricobservations to identify 12 new γ Doradus stars. Two of the 12systems are double-lined binaries that show obvious velocityvariability. Five other stars have metallic lines with compositeprofiles characterized by a narrow feature near the center of each broadcomponent. Spectrograms of the Hα line indicate that all fivestars are binaries rather than shell stars. The remaining five stars inour sample are probably single. All 12 stars are photometricallyvariable with amplitudes between 6 and 87 mmag in Johnson B and periodsbetween 0.3 and 1.2 days. Four stars are monoperiodic; the rest havebetween two and five independent periods. The variability at all periodsapproximates a sinusoid. Although many of the stars lie within theδ Scuti instability strip, none exhibit the higher frequencyvariability seen in δ Scuti stars. We have increased the sample ofknown γ Doradus stars by 40% and revised the positions of a numberof variables in the H-R diagram by accounting for duplicity. Our list of42 confirmed γ Doradus variables gives some of their properties.All are dwarfs or subgiants and lie within a well-defined region of theH-R diagram that overlaps the cool edge of the δ Scuti instabilitystrip. We compare the observed location of the γ Doradus variableswith a recently published theoretical γ Doradus instability stripand find good agreement.

The Kreinin-Murri Method for Absolute Determination of Equatorial-Star Declinations.
Not Available

Submit a new article


Related links

  • - No Links Found -
Submit a new link


Member of following groups:


Observation and Astrometry data

Constellation:Οφιούχος
Right ascension:17h31m57.72s
Declination:+00°02'33.0"
Apparent magnitude:6.767
Distance:214.592 parsecs
Proper motion RA:10.9
Proper motion Dec:-4.9
B-T magnitude:8.195
V-T magnitude:6.885

Catalogs and designations:
Proper Names
HD 1989HD 158921
TYCHO-2 2000TYC 414-1201-1
USNO-A2.0USNO-A2 0900-09966329
HIPHIP 85806

→ Request more catalogs and designations from VizieR