Sirius, a binary system, is the brightest star in the night sky. The largest of the two stars, Sirius A, is about 25 times luminous than the Sun, and Sirius is relatively nearby, at less than 9 light years from our Solar System.
On Monday night, for a few areas of the South and Central America, as well as the Caribbean, Sirius will probably briefly disappear. According to the International Occultation Timing Association, this will occur as a small asteroid passes in front of the star, occulting it for up to 1
In this case, the asteroid 4388 Jürgenstock will have an apparent diameter just an iota bigger than Sirius. The angular diameter of the asteroid is about 0.007 arcseconds (an arcsecond is 1 / 3.600th of a degree of the night sky), while Sirius's angular diameter is 0.006 arcseconds. So, as the asteroid passes in front of Sirius, the star will briefly dim, perhaps, completely, before quickly brightening again. Sirius may appear to blink once, slowly.
Unfortunately, the path for this event will occur mostly over water. Based on maps from IOTA, the occultation will appear over snippets of Argentina and Chile, Panama, the tip of Haiti, and possibly Turks and Caicos. There remains some uncertainty in the timing, which is expected to occur along its path starting at 5:11 UTC and ending at 5:26 UTC on Tuesday, Feb. 19.
With a diameter of 4.7km, this inner-asteroid belt object was discovered in 1964 by astronomer named-you guessed it-Jürgen Stock. This occultation should allow astronomers a rare opportunity to better characterize the dimensions of the asteroid. This is likely to have an irregular shape-further contributing to the uncertainty about the extent to which it will block the light from Sirius.