waxing, "shrinking" Venus well placed at Sunrise

Event Date: September 9th
Time: 10:00 PM


Brief

   The rise-gap between Venus and the Sun is slowly starting to shrink, now that our planet is past greatest elongation.  As Venus starts to gradually approach superior conjunction, it is also waxing and shrinking in angular size, as seen from Earth.  Venus continues to move further from us each day, after being closest to us during inferior conjunction.  Take a look below at Venus with its orbit, along with the ecliptic featured, shortly before Sunrise.  The ecliptic makes a big angle with the horizon right now and that is still gradually improving between now and early October. 

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

Detailed

As the separation between the Sun and Venus decreases, the geometry of the eastern morning sky continues to improve for about another month.  Therefore, Venus doesn't seem to change in altitude at the official time of Sunrise each morning.  Venus is further north of the Sun and currently, 44º separated from our star.  As we get to the later weeks of fall, Venus' closing in of the Sun means that it will lose northern declination quickly and be nearly the same as that of the Sun by early winter.  We will not beable to see Venus high above the horizon for much of winter, and will gradually lose it to the Sun's glare in March.  At that time, the geometry of the eastern, morning sky is nearly its worst.
   Venus also varies in ecliptic latitude each month, passing ascending node next season.  Remember to try to view Venus for awhile after Sunrise, since it is bright enough to stand out against the gradual-lightening morning sky.  As the weeks pass and the Sun rises later each morning by a minute and a half at best, it gives us more time to have the sky darker and easier to see Venus for several more minutes after Sunrise.