Wednesday, July 07, 2010
Here's an interesting article from Raumfahrer in German, on the upcoming occultation of a star called Delta Ophiuchi by an asteroid known as 472 Roma, a somewhat typical asteroid of almost 50 km in diameter located in the Asteroid Belt. Occultations are not rare in astronomy but one of this nature is, where a star easily visible with the naked eye is obscured by an object passing in front. Most other occultations occur with stars far too dim to see with the naked eye and thus require quite a bit of preparation and equipment to observe. For anyone in the path of the occultation though, for the 5.6 seconds that the asteroid passes in front of the star it will simply disappear from view. The asteroid itself has a magnitude of 13.5 so someone with an eight-inch or so telescope will be able to observe the asteroid as well during the occultation, but for anyone else it will be invisible.
Here's the path of the occultation from Finland to Spain and Portugal. As you can see, some of the major cities over which the occultation will occur are Tampere, Stockholm, Copenhagen, Hamburg, Bremen, Essen, near Hanover/Brussels/Luxembourg/Paris, plus Bordeaux, Bilbao, and the Canary Islands.
An article in French on the occultation can also be seen here; it includes a video taken of a former occultation as well as a more detailed view of where it can be seen for those living in France.
Also, remember that Rosetta's encounter of the much larger asteroid 21 Lutetia is happening just...3 days, 10 hours, 44 minutes and 35 seconds from now. Raumfahrer has a countdown up in the top left.