Saturday, May 05, 2007
Asteroid Vesta can be seen with the unaided eye
Every so often, the orbit of Asteriod 4 Vesta brings it close enough for it to become (just) visible to the unaided eye. This year Vesta will be at its brightest for 18 years.
At the moment Vesta is magnitude 5.9, just above the visual threshold for a dark sky site (or would be if the nearly full Moon wasn't near by tonight). Later in the month, it will be magnitude 5.4. The keen eyed should easily spot it with a bit of practice. Even people in suburban sites should be able to see it, although you may need to spot it in binoculars first to orient yourself.
Chart in same orientation as above, showing field of view of 10x50 binoculars (click to enlarge).
It is quite easily visible in 10x50 binoculars, approximately half way between zeta and eta Ophichus. It also forms the apex of a triangle with Jupiter and Antares (alpha Scorpii) as its base.
UPDATE: A big Hello! to people coming here from Universe Today. Have a look at my other Vesta spotting image. Printable black and white charts are here.