Observation Notes:
This is the closest double I’ve observed yet. It appeared as a single, slightly elongated star that points west-northwest/east-southeast. PA appears to be either 120° or 300°, depending on which star is the primary. According to notes in the WVDSC, the pair has a 123 year period.
| Subject | Zeta Bootis (−1865) |
| Classification | Double Star |
| Position (J2000) | Bootes [RA: 14:41:09 / Dec: +13:43:41]* |
| Position Angle* | 303° (1991) |
| Separation* | .91″ (1991) |
| Magnitudes* | 4.5 / 4.6 |
| Spectral Types* | A2/A2 |
| Date/Time | SEP 03, 2006 – 10:00 PM MST (SEP 04, 2006 – 05:00 UT) |
| Observing Loc. | Flagstaff, AZ – Home |
| Instrument | Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L) |
| Eyepieces/Mag. | 10 mm + 2X Barlow (240X) |
| Conditions | Partly cloudy, calm |
| Seeing | 4/10 |
| Transparency | NELM Mag ~4.0 |
| References | Tycho Double Star Catalogue (Fabricius+ 2002); The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996); and Catalog of Components of Double & Multiple Stars (Dommanget+ 2002) via VizieR |
*Based on published data.