HUT Observatory

What Our Equipment Allows

DSC_0060The CCD cameras, filters, and 16-inch telescope at HUT Observatory are ideally suited for measuring the position, brightness, and color of celestial objects.  The equipment is computer controlled, and the timing of the electronic images is recorded automatically to a great accuracy.  Timing is very important in many projects, such as the measurement of moving solar system objects, including the rotation of asteroids.  Positional measurements allow more accurate orbits to be computed for objects in the solar system.  This is especially important for the class of asteroids called near-Earth objects, or NEOs, some of which can potentially (eventually) strike Earth.

Asteroids are too small for astronomers using conventional telescopes to image their surfaces directly.   The rotation of asteroids can nevertheless be determined by plotting their changing brightness.  Because they are irregularly shaped, asteroids reflect a varying amount of sunlight.  When plotted against time, the resulting graph is called a light curve.  The brightness pattern repeats as the object rotates, and the period of the cycle, which can range from a few minutes to many hours, is essentially equal to the rotation of the asteroid.  In such studies it is possible to occasionally detect binary asteroids — in other words, asteroids that have moons.  Our 2012 publication on minor planet number 1036, Ganymed, was a collaboration involving  six authors from three countries.  Our data suggested that Ganymed, a near-Earth object, was binary.  This was confirmed shortly afterwards by astronomers using radar techniques.

Stars are also very interesting targets for similar measurements.  A new short-period variable star recently discovered by Ji Seok Kim at Phillips Academy was confirmed using images from HUT Observatory.  This object, which changes brightness in a cycle lasting just over eight hours, has proven to be a pair of stars orbiting each other in an amazingly close configuration – essentially in contact — and aligned so that they eclipse each other as seen from Earth.  The system is thus an example of a class of eclipsing binary stars called contact binaries.

HUT Observatory also has a collection of historical instruments that facilitate projects and publications in the history of astronomy, particularly in the specialty of the history of instrumentation.

Additional portable equipment has allowed observations and publications related to solar system occultations — fleeting events whereby a moving solar system object, like Pluto, appears to pass in front of a vastly more distant star.  Timing such phenomena allows an improved understanding of the size of the moving object and, in the case of Pluto, an improved understanding of its tenuous, frigid atmosphere.  For these projects, HUT Observatory collaborates with astronomers based at Williams College and MIT.