Venus in line with bright stars Castor and Pollux

Turn your gaze to the west just after the sky gets dark in the evening. The brilliant star low on the horizon is the 2nd planet from the Sun, Venus. Over the next few nights watch as Venus lines up with and then moves past the ‘twin” stars of Gemini, Castor and Pollux.

Also note Mars quickly moving away from Regulus after their close encounter last weekend.

Now a little background info on the Venus-Gemini trio:

Venus
magnitude -3.9
2nd planet from the Sun
0.95 Earth diameters
0.86 Earth masses
1.2 AU from Earth (180,000,000 km or 110,000,000 miles)

Pollux
magnitude +1.2
brightest star in constellation of Gemini
K0 type orange giant star
younger but more evolved than Sun
1.7 solar masses
8.8 solar diameters
32 times brighter than Sun
may have an 2 Jupiter mass planet
33.7 lightyears from Earth (198,105,444,000,000 miles away)

Castor
magnitude +1.9
2nd brightest star in constellation of Gemini
sextuplet star system (made up of 3 very close pairs)
biggest star has 2.2 solar masses, 2.3 solar diameters
biggest star is 30 times brighter than the Sun
51.6 lightyears from Earth (303,337,308,000,000 miles away)

Early evening view to the west on June 11, 2010. Created with Stellarium.

About Carl Hergenrother
I am a professional astronomer specializing in the study of comets, asteroids and meteors. This blog will focus on my professional and amateur work in this field

One Response to Venus in line with bright stars Castor and Pollux

  1. TDB says:

    Love the all the details you provide and the Stellarium sky map! Got some photos of this conjunction looking west over the Olympic Mountains in WA state. (Very lucky that it was clear.)

    http://thedailybite.wordpress.com/2010/06/11/watch-for-the-conjunction-of-venus-with-twin-stars-castor-and-pollux-tonight/

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