Tau and 83 Leonis (Struve-A 19 / Struve )

Sketch of Tau and 83 Leonis (Struve-A 19 and Struve 1540 / STFA 19 and STF 1540)

Sketch of Tau and 83 Leonis / Struve-A 19 and Struve 1540

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Observation Notes:

This striking double double consists of widely spaced, colorful Tau Leonis (orange-yellow and blue) and 83 Leonis (yellow and red-orange).

Subject Tau Leonis (84 LEO / Struve-A 19 / STFA 19)
83 Leonis (Struve 1540 / STF 1540 / ADS 8162)
Classification Double Star
Position (J2000)* Leo:
Tau LEO: [RA: 11 27 56.2 / Dec: +02 51 22.6]
83 LEO: [RA: 11 26 45.3 / Dec: +03 00 47.2]
Position Angle Tau LEO:
AB: 185° [My Measurement 2009.9]
AB: 181° [WDS 2004]*
83 LEO:
AB: 150° [My Measurement 2009.9]
AB: 150° [WDS 2008]*
Separation Tau LEO:
AB: 90″ [My Measurement 2009.9]
AB: 88.9″ [WDS 2004]*
83 LEO:
AB: 29″ [My Measurement 2009.9]
AB: 28.2″ [WDS 2008]*
Magnitudes* Tau LEO: A: 5.1; B: 7.1
83 LEO: A: 6.6; B: 7.5
Spectral Types* Tau LEO: A: G8II-III; B: G5
83 LEO: A: G7V; B: K4V
Date/Time NOV 27, 2009 – 5:05-5:15 AM MST (NOV 27, 2009 – 12:05-12:15 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