Mercury as Springtime Morning Star

Panorama of the eastern sky with Mercury and the Moon as seen from Chicago 30 minutes before sunrise from 2017 APR 30 to JUN 14 - 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 morning apparition in the eastern sky following its inferior conjunction between Earth and Sun on 2017 APR 20. This should be a poor apparition for observers north of the tropics, but a better one one for those further south.

  Apparent direct motion in right ascension resumed on 2017 MAY 02. Mercury reached its Greatest Western Elongation of 25.8° on MAY 18. Through a telescope on MAY 23 it appeared in dichotomy, i.e. 50% illuminated like a Half Moon. Prior to that Mercury appeared as a crescent and afterward gibbous. By the standard of 30 minutes before sunrise for Chicago, it achieved its highest altitude of 4.2° on MAY 25. While increasing in brilliance, Mercury will fall to superior conjunction behind Sun on JUN 21

   Mercury will not appear near other bright planets during this apparition. It will appear near the stars Alcyone (Pleiades) 2017 JUN 07, Aldebaran JUN 11.

NOTE: Event dates in this article are for North American Central Time at those moments nearest to 30 minutes before sunrise 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

Mercury 01
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