| C1900.0 | : | 09562+1754 |
|---|---|---|
| C2000.0 | : | 100140427+17243270 |
| Comp. | : | B |
| Magn. | : | |
| Spect. | : | M1 ; M3 |
| BD +18 2307 | GAIADR2 623076270045202048 | GAIADR3 623076270045202048 | GCVS XY Leo |
| HIP 49136 |
| Element | Value | Std. dev. | |
|---|---|---|---|
| Period (d.) | : | 0.8050 | |
| Epoch (xJD-2,400,000.0) | : | 46426.319 | (see note) |
| Reference T0/epoch | : | JD | |
| Eccentricity | : | 0.0 | |
| omega primary (deg.) | : | 0.0 | |
| K1 (km/s) | : | 46.1 | |
| K2 (km/s) | : | 64.6 | |
| V0 (km/s) | : | -37.7 | |
| sigma residuals primary | : | ||
| sigma residuals secondary | : | ||
| #RV primary | : | ||
| #RV secondary | : | ||
| Grade | : | 2.0 | |
| Contributor | : | DAO | |
| Status | : | PUB | |
| Bibcode | : | 1987ApJ...317..333B | |
| Derived quantities (on the fly, from the above quantities) | |||
| a1sini (km) | : | 510306 | 0 |
| a2sini (km) | : | 715093 | 0 |
| m1sin**3 i (sol.mass) | : | 0.0662806 | 0 |
| m2sin**3 i (sol.mass) | : | 0.0472993 | 0 |
The contact binary XY Leo has long been known to display period changes that were apparently themselves periodic. A third body has often been suspected, but never detected until Barden found the lines of two other spectra in the combined light of the system and derived orbital elements for another short-period pair. The presumption is therefore strong that these two pairs are revolving around their common centre of mass in about 20 years. Emission features at H-alpha and H and K are ascribed by Barden to this second binary which he believes to be of the BY Dra type. The orbit is assumed circular and the epoch is the time of superior conjunction of the primary component. Barden gives no direct estimate of the magnitude of the companion, which is not seen separately from the contact binary and the spectral types are estimates based on masses derived from an assumed orbital inclination (31 deg) for the new pair. Barden believes the orbits in the quadruple system are not coplanar.
