October 14, 2019

AstroEvent: See Mercury at its 2011 Morning Best.

Never seen the planet Mercury before? This coming week offers a good time to try, as the inner-most world undergoes its best morning apparition for northern hemisphere viewers. The tiny world reaches a greatest elongation of 18.1° degrees west of the Sun on September 3rd at a brightness ranging from about -1 magnitude to 0.0 on the dime. [Read more...]

Astro-Event: An Asteroid Occults a Bright Star.

One of the best occultations of a bright star occurs this week for observers along a line from western Canada down the U.S. west coast. At around 10:00 UT, on the morning of April 6th, 14th magnitude asteroid 824 Anastasia will occult, or pass in front of, the bright +2.5 magnitude star Zeta Ophiuchi for up to 8.6 seconds. This is a rare event in that the occulted star will be visible with the naked eye! Stellar occultations give us the rare opportunity to profile the shape of an asteroid; if enough folks are lined up along the graze line and make and submit accurate observations, a chord map of the “shadow” of the asteroid can be plotted. Binary asteroids have even been discovered by amateur astronomers using this method! Anyway, if you’re located anywhere along the predicted path and the sky is clear, don’t miss this rare event!

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