Event Date: July 18th
Time: 5:30 AM
Brief
We are only a few weeks away from Venus' greatest western elongation (g.w.e). It seems as if we acknowledged that not long ago when it happened east of the Sun in late March; one of the first Venus highlights of my blog when starting it about a week before that.
Here is Venus with its orbit showing, as we see it approaching g.w.e. Since it started rising before the Sun the morning of June 6th, Venus has separated from the Sun by almost 42º and rising 2 hours, 46 minutes earlier. It continues to slightly change configuration with (unlabeled) Jupiter and Aldebaran, above and upper right respectively. Notice the difference in brightness for these three.
Time: 5:30 AM
Brief
We are only a few weeks away from Venus' greatest western elongation (g.w.e). It seems as if we acknowledged that not long ago when it happened east of the Sun in late March; one of the first Venus highlights of my blog when starting it about a week before that.
Here is Venus with its orbit showing, as we see it approaching g.w.e. Since it started rising before the Sun the morning of June 6th, Venus has separated from the Sun by almost 42º and rising 2 hours, 46 minutes earlier. It continues to slightly change configuration with (unlabeled) Jupiter and Aldebaran, above and upper right respectively. Notice the difference in brightness for these three.
Detailed
Since that last greatest elongation, Venus have encountered best apparent magnitude, greatest brilliancy, the last transit of most of our lifetimes across the Sun and recently, best magnitude and greatest brilliancy again. Since I spent alot of time on that when east of the Sun, I will hold off on the calculations on finding when greatest brilliancy is. Refer back here for when it reached greatest brilliancy then. Also, there has been so much to talk about with Venus and Jupiter near the star clusters and each other, that took some entry date-space this month and I didn't want to ignore those attractive sightings.
As the geometry of the eastern morning sky improves and Venus continues to reach g.w.e., the time-gap between it and the Sun rising will increase quickly. Even after g.w.e., Venus will remain separated enough from the Sun that the gap continues to increase for several more days. When observing Venus in a telescope, it has shrunk from nearly 1 arc-minute in angular diameter to about half that at 34 arc-seconds. The percent illuminated is 32, putting it very close to greatest brilliancy. Take a look at the phase and size here, with a field of 1/2º.
Since that last greatest elongation, Venus have encountered best apparent magnitude, greatest brilliancy, the last transit of most of our lifetimes across the Sun and recently, best magnitude and greatest brilliancy again. Since I spent alot of time on that when east of the Sun, I will hold off on the calculations on finding when greatest brilliancy is. Refer back here for when it reached greatest brilliancy then. Also, there has been so much to talk about with Venus and Jupiter near the star clusters and each other, that took some entry date-space this month and I didn't want to ignore those attractive sightings.
As the geometry of the eastern morning sky improves and Venus continues to reach g.w.e., the time-gap between it and the Sun rising will increase quickly. Even after g.w.e., Venus will remain separated enough from the Sun that the gap continues to increase for several more days. When observing Venus in a telescope, it has shrunk from nearly 1 arc-minute in angular diameter to about half that at 34 arc-seconds. The percent illuminated is 32, putting it very close to greatest brilliancy. Take a look at the phase and size here, with a field of 1/2º.
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| click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
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