The elusive little planet Mercury has begun its apparition as a morning star following its inferior conjunction between Earth and Sun on 2009 MAY 18. This will be a somewhat challenging apparition for northern hemisphere observers.

I’ve created graphics for observers in both the northern and southern hemispheres illustrating Mercury’s morning apparition.  Those in the south have the better view.  They can be seen at: http://www.curtrenz.com/astronomical.html

All dates given here are based on CDT.  Mercury will reach its greatest western elongation of 23.5° from the Sun on JUN 13.  It will achieve dichotomy (50% illuminated like a Half Moon) on JUN 19.  Before that date it will be a crescent and afterward gibbous.   It will reach its greatest altitude at 25 minutes before sunrise from Chicagoland on JUN 21 at 7.3°.  While increasing in brightness, it will then fall to superior conjunction behind the Sun on JUL 13.

Magnitude -0.1 Mercury will appear to pass 8 arcminutes north of magnitude +3.5 Epsilon Tauri on JUN 21.  The waning crescent Moon will appear to pass 6° north of Mercury on that same date.