Post by Centaur on Sept 23, 2009 0:26:36 GMT -6
The elusive little planet Mercury has begun its apparition as a morning star following its inferior conjunction between Earth and Sun on 2009 SEP 20. The celestial geometry is ideal at this time of year for northern hemisphere observers.
I’ve created a diagram illustrating Mercury’s morning apparition as observed from Chicagoland. However, it should well serve most northern hemisphere observers. It can be seen at: www.curtrenz.com/astronomical
All dates given here are based on CDT. Mercury will reach its greatest western elongation of 17.9° from the Sun on OCT 05. It will achieve dichotomy (50% illuminated like a Half Moon) on that same date. Before that date it will be a crescent and afterward gibbous. It will reach its greatest altitude at 30 minutes before sunrise from Chicagoland on OCT 06 at 11.0°. While increasing in brightness, it will then fall to superior conjunction behind the Sun on NOV 05.
Photos and descriptions of Mercury’s morning apparition would be welcome additions to this thread.
I’ve created a diagram illustrating Mercury’s morning apparition as observed from Chicagoland. However, it should well serve most northern hemisphere observers. It can be seen at: www.curtrenz.com/astronomical
All dates given here are based on CDT. Mercury will reach its greatest western elongation of 17.9° from the Sun on OCT 05. It will achieve dichotomy (50% illuminated like a Half Moon) on that same date. Before that date it will be a crescent and afterward gibbous. It will reach its greatest altitude at 30 minutes before sunrise from Chicagoland on OCT 06 at 11.0°. While increasing in brightness, it will then fall to superior conjunction behind the Sun on NOV 05.
Photos and descriptions of Mercury’s morning apparition would be welcome additions to this thread.
