The 29 Great Dog (29 CMa / UW CMa) is a variable star in the Great Dog constellation. The main component is a blue supergiant of spectral class O with an average apparent brightness of +4.88 m . The companion, most likely, is the white-blue star of the main sequence of the spectral class OB.
| 29 Big Dog | |||
|---|---|---|---|
| Star | |||
  | |||
| Observational data ( Epoch J2000.0) | |||
| Right ascension | |||
| Declination | |||
| Distance | 3000 of sv. years (900 pc ) | ||
| Visible magnitude ( V ) | from +4.84 to +5.33 | ||
| Constellation | Big Dog | ||
| Astrometry | |||
| Radial velocity ( R v ) | 13.5 km / s | ||
| Proper motion (μ) | RA: -3.12 mas per year Dec: 2.68 mas per year | ||
| Parallax (π) | 1.09 ± 0.65 mas | ||
| Absolute magnitude (V) | from -4.97 to -4.48 | ||
| Specifications | |||
| Spectral class | O7Ia: fp / OB | ||
| Color Indicator ( B - V ) | -0,14 | ||
| Variability | EB (β lyr) / KE | ||
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| Information in databases | |||
| SIMBAD | data | ||
29 Bolshoy Psa belongs to eclipse variables of type β Lyrae , has a variability period of 4.39 days, varying magnitude from +4.84 m to +5.33 m .
The system is removed from the Sun at a distance of 3000 ± 1800 light years and consists of two contacting stars of spectral class O with unknown parameters. The mass ratio of the stars is unknown, according to some estimates, the luminosity for the primary varies between 870 and 410 thousand times the Sun and 170 and 240 times for the second component, respectively. Depending on this parameter, their masses vary, respectively, between 107 and 54 solar for the first and 11-17 solar masses for the second component.