Mercury low at Sunset

Event Date: June 2nd
Time: 8:45 PM

Brief

   Mercury started its east-of-Sun cycle at about the same time that it reached perihelion.  As a result of that, it will dim quickly compared to the last time that it was east of the Sun in February and March.  For that excellent apparition, perihelion was near the time of greatest elongation, which happened when the Sun was still south of the celestial equator and twilight time was much shorter than this month.  By the end of this month, Mercury will be visible to the eye alone with a fair apparition.  By that time, it will already be slightly further south than the Sun, and Sunsets will be their latest of the year with a maximum civil twilight duration of nearly 40 minutes.  After that, we will lose Mercury quickly in the Sun's brightness, as it also sinks further south of the Sun.

Detailed

   Despite all the cons, we will have Mercury far enough north on the celestial dome to easily see it slowly set after the Sun until about a week before greatest elongation.  Try to pick it up with binoculars about 30 minutes after Sunset once separated far enough.  At its greatest separations from the Sun, specifically 8-10 days before greatest elongation, it will still be bright enough to pick out somewhat easily with the eye.  The first image above showed Mercury 3º above the horizon.  That sounds low, yet with a -1.5 magnitude, that is still barely visible enough to see through atmospheric pollution with minimal optical aid.  Mercury sets 42 minutes after the Sun, and that gap increases by about 5 minutes tomorrow.  With a current declination gap this evening of over 2º between the Sun and Mercury, and an almost 3 1/2º gap tomorrow, Mercury's just-post perihelion days will be some of the better to see Mercury. 
This second image to follow is a 1/2º zoom in, showing Mercury as a small, waning gibbous, of 5.2 arc-seconds.

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.