Iota Leonis (Struve 1536)

Sketch of Iota Leonis (Struve 1536 / STF 1536)

Sketch of Iota Leonis (Struve 1536)

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Observation Notes:

Iota Leonis was ridiculously difficult in poor seeing–only resolving for moments as a dim fuzzball that was fainter than the primary’s flickering diffraction pattern. They both appeared colorless. Smyth saw pale yellow and light blue while Hartung saw deep yellow and whitish.

Subject Iota Leonis (STF 1536; 78 Leonis; ADS 8148)
Classification Double Star
Position (J2000)* Leo [RA: 11 23 55.5 / Dec: +10 31 46.2]
Position Angle AB: 97° [My Measurement 2009.9]
AB: 105° [WDS 2007]*
Separation AB: 3″ [My Measurement 2009.9]
AB: 1.9″ [WDS 2007]*
Magnitudes* A: 4.1; B: 6.7
Spectral Types* A: F4IV; B: F5V
Date/Time NOV 27, 2009 – 5:30 AM MST (NOV 27, 2009 – 12:30 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