January 2, 2012

Like a number of research universities, Kagoshima University has its own observatory. Nestled in rolling hills reminding me of Marin County and surrounded by beef cattle fields* (also a university property), the observatory is home both radio and visible wavelength astronomy facilities. A large radio telescope downhill from the optical observatory faded into the evening light.

Our telescope was a 1-meter reflector, operated by a posse of graduate students.  How to change the mirror configuration?  Put one of said grad students on a ladder, then grab his belt loops so he doesn’t fall into the primary mirror.

Why travel several thousand miles by squeezing onto Shinkansen like sardines to visit this observatory? A minor planet, known by its number (20000) or its name Varuna after a Hindu god, was predicted to pass in front of a particular star, occulting the distant stellar object’s light. Varuna’s shadow as cast by the star would sweep across the Pacific Ocean that night, ostensibly visible from Japan, Hawaii, China, Thailand, and other neighboring countries.  The actual occultation only occurs for a few seconds.

(20000) Varuna's shadow predicted track across the Pacific

Measuring this dip in brightness helps inform better orbital models for Varuna, search for companion moons, and even probe the existence of an atmosphere around the tiny, icy world.

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