Sketch of Tau Leonis / Struve-A 19
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Observation Notes:
I saw this widely spaced, colorful double as Orange-yellow and blue. Despite a G8 primary and G5 secondary, other observers also pick up the blue color contrast in the companion: 33 Doubles – Tau LEO. Sissy Haas sees them as lemon yellow and gray. They make a striking, low-power, double-double with nearby 83 Leonis.
| Subject | Tau Leonis (84 LEO / Struve-A 19 / STFA 19) |
| Classification | Double Star |
| Position (J2000)* | Leo [RA: 11 27 56.2 / Dec: +02 51 22.6] |
| Position Angle | AB: 185° [My Measurement 2009.9] AB: 181° [WDS 2004]* |
| Separation | AB: 90″ [My Measurement 2009.9] AB: 88.9″ [WDS 2004]* |
| Magnitudes* | A: 5.1; B: 7.1 |
| Spectral Types* | A: G8II-III; B: G5 |
| Date/Time | NOV 27, 2009 – 5:15 AM MST (NOV 27, 2009 – 12:15 UT) |
| Observing Loc. | Flagstaff, AZ – Home |
| Instrument | Orion SkyQuest XT8 Dobsonian (203 mm dia./1200 mm F/L) |
| Eyepieces/Mag. | Pentax XW10 + 2X Barlow (240X) Meade Astrometric EP + 2X Barlow (200X) |
| Conditions | Clear, cold, hazy |
| Seeing | 3-4/10 Pickering |
| Transparency | Mag 5.5 NELM |
| *References | The Washington Visual Double Star Catalog (Mason+ 2001-2009); Catalogue of Stellar Spectral Classifications (Skiff, 2009); SIMBAD; Double Stars for Small Telescopes – Sissy Haas |