The magnitude 7.6 asteroid (4) Vesta will occult the magnitude 8.8 star HIP 76876 at 07:16 UT , on the 31st January 2007 . The event will be observable from Uruguay, Argentina, Chile
Position(2000): RA = 15 41 53.572 Dec.= -12 45 35.62
Vesta was the fourth asteroid to be discovered. With a diameter of 525 kilometres, Vesta appears to even the largest telescopes as a speck of light.
Vesta holds the distinction of being the brightest asteroid, occasionally being visible to the naked eye. Just now Vesta is at "opposition" and is an ideal time to observe the asteroid. Vesta reflects 25 percent of the sunlight falling onto its surface, the moon, by comparison, reflects only 12 percent. Opposition is when a celestial object appears opposite in the sky from the sun. It's during this time that a body lies closest to Earth and reaches its brightest. Vesta will officially reaches this point on January 5, 2006, when it lies only 143,781,413 miles away.
To be sure it's Vesta, make a sketch of the stars you see and return night after night. You should soon notice that one of these "stars" is moving through this stellar pattern. This, of course, is no star; it's Vesta.