Time: 5:45 AM
Brief
This is the third and last of this series featuring the three brightest objects in the sky this month when the Sun is below the horizon: in line, Jupiter, the waning crescent Moon and Venus. with the latter very close to greatest eastern elongation. The image, for which showed the stars of the Winter Circle yesterday, has all those stars still showing, but not labeled this time; I want to focus on the solar system bodies instead. With the aforementioned in line, I will also show their orbits. Looking further east, we see the different inclinations of the three orbits, with most-distant Jupiter having its following along the ecliptic closer than inner-planet Venus and the Moon.
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click on image to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp. |
Detailed
At 45.7º this isn't the furthest separated that we see Venus from the Sun, as it can be as far as between 47-48º. The variance is partly because sometimes we see Venus closer to aphelion or perihelion, although sometimes it depends on where we see it related to the Sun from our position. More impressively, as the geometry of the eastern sky improves over the next couple of months; the declination gap between the Sun and Venus grows, as Venus slowly loses declination towards the equator while the Sun moves towards south at its fastest-- particularly the days surrounding the September equinox. Venus is also close to dichotomy, at 50% illuminated. The more it waxes, unfortunately the more it seems to shrink in angular size. Although this hardly affects its apparent magnitude right now, we should remember that as Venus gets close to superior conjunction in about 5 months, it will be seen much smaller in a telescope. By the time it reaches conjunction, it is about 1/6 the angular size that it was at inferior conjunction (as we saw it during the transit of the Sun), while being about 6 times further from us than it was during that week.
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