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  • Rapt in Awe

    My Journey through the Astronomical Year

    Think of this as a "companion text" to this, the main web site. Not required reading, butI hope you'll find it interesting and helpful.

Venus gives the Little King a morning kiss!

Looks eats in the morning sky of October 3, 2012. Click image for larger version – prepared from Starry Nights Pro screen shot.

Exactly how this event looks to you really depends on where you are. From my observation point on the Eastern Seaboard, I’ll catch Venus and Regulus very close to their closest approach with a separation of about 8 minutes of arc shortly after 4 am on October 3, 2012.  By the time the pair rises for West Coast viewers. the separation will be closer to 12 minutes. And, of course, those in “Down East” Maine will have a slightly better view of the event than I do.

But for all of North America and for some other places as well, it will be fun – weather permitting – to see Venus at magnitude -4.1 come so close to a first magnitude star, Regulus, at magnitude 1.34. That means Venus will be about 100 times as bright as Regulus, and I’m pretty sure this will make it impossible to see the star with your naked eye, though it should make a real cool view for binoculars and small telescope users. Regulus (Latin for “little king” or “prince.”) gets these close calls because it is so close to the ecliptic – the green line in our chart – which is the general area of the sky where the planets are found. On July 8, 1959, Regulus was occulted by Venus – that is, completely covered.  That will happen again on October 1, 2044. Of course the two aren’t really close. Venus is in our solar system and at this time about eight light minutes from us, whereas Regulus is 78 light years away.

How does this compare with the view of what is probably the best known double star, Mizar and Alcor in the handle of the Big Dipper?  Many people can split this pair with their naked eye, but they are  11.6 minutes apart.  So just considering the separation in minutes of arc, Venus and Regulus should be very, very difficult to split with  the naked eye. But Mizar and Alcor are  less than two magnitudes apart – a difference of about 6 times in brightness – and that makes it much easier to split them.

Still – I plan to watch starting about 4 am EDT when the pair are high enough above the horizon to see easily. As sunrise nears, the gap will widen to 10 or 11 minutes and separating them may get a bit easier as the glare of Venus will be diminished against the pre-dawn glow. If nothing else, this will certainly drive home the message of how quickly Venus is moving. By the next morning they are separated by more than a degree – still nice to see – and by October 8th or 9th you’ll be hard pressed to fit them both in the same binocular field of view!

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