Venus and Uranus (2012 Feb 08)

posted: 1965 days ago, on Thursday, 2012 Feb 09 at 05:58
tags: astronomy, astrophotography, Southern Sky Highlights 2012, Venus, Uranus, Kos Coronaios.

Venus and Uranus are pairing up in the evening sky over the next few days.

Kos's photo on the right (with Uranus arrowed), taken Wednesday Feb 08, shows the duo 1.5-degrees apart.

The brightish star between them (mag 6.3) is known as HR 2, or HD 6. Either way, a very posh address.

Venus shines brightly at mag -3.8, while Uranus is a more gentle mag +5.9. Venus is 7600 times brighter than Uranus at the moment, a difference in intensity I have no way of relating to.

To think in terms of magnitudes and intensity can be tricky. For example, how many times is Uranus brighter than that star? Turns out, its 1.4 times brighter.

The two planets differ in many other ways. For example, in their distances from Earth: Uranus is 20 times further away from us.

Yet another difference is their sizes: Uranus is 73 times bigger than Venus (by volume), and 18 times heavier (by mass). But Venus wins when it comes to apparent size: it is five times bigger than Uranus at the moment (15.9 arcseconds vs. 3.3 arcseconds).

And they are similar in some regards. For example, their surface gravity is almost the same. On Earth, the pull of gravity is g = 9.8 m/s2, but it's less on these two planets - Venus is 8.87 and Uranus is 8.69.

As for sex-appeal, that's for you to decide.

nothing more to see. please move along.