Mercury as Springtime Evening Star

Panorama of the western sky with Mercury and the Moon as seen from Chicago 30 minutes after sunset from 2017 MAR 13 to APR 16 - See article below.

Mercury - Elongations & Altitudes - 2017

The planet’s elongations from the Sun and altitudes above the horizon as viewed from latitude N 42°

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Elusive Mercury is presenting its early evening apparition in the western sky following its superior conjunction behind the Sun on 2017 MAR 06. This should be an excellent apparition for observers north of the tropics, but virtually impossible for those south of the tropics.

   Through a telescope on 2017 MAR 29, Mercury will appear in dichotomy, i.e. 50% illuminated like a Half Moon. Prior to that it will appear gibbous and afterward as a crescent. Mercury will reach its Greatest Eastern Elongation of 19.0° on MAR 31. By the standard of 30 minutes after sunset for Chicago, it will achieve its highest altitude of 12.2° on APR 01. Apparent retrograde motion in right ascension will commence on APR 09. While decreasing in brilliance, Mercury will fall to inferior conjunction between Earth and Sun on APR 19.

  The Moon will appear near Mercury 2017 MAR 28, but there will be no occultation.

NOTE: Event dates in this article are for North American Central Time at those moments nearest to 30 minutes after sunset for Chicago.

Mercury Angular Diameter - 2017

Graph of the apparent angular diameter of Mercury measured in arcseconds  -  Distance in AU = 6.68 / angular diameter

Mercury Illumination Phase - 2017

Graph of the percentage of Mercury’s apparent disk illuminated

Mercury Stellar Magnitude - 2017

Graph of the brightness of Mercury measured in stellar magnitude

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© Curt Renz

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