Palomar Testbed Interferometer

The Palomar Testbed Interferometer is a near-IR, long-baseline stellar interferometer located at Palomar Observatory in north San Diego County. It was built by Caltech/JPL and is intended to serve as a testbed for developing interferometric techniques to be used at the Keck Interferometer. It began operations in 1995 and acheieved routine operations in 1998, producing more than 35 refereed papers in a variety of scientific journals covering topics from high precision astrometry to stellar masses, stellar diameters and shapes.

PTI is notable for being equipped with a "dual-star" system, making it possible to simultaneously observe pairs of stars; this cancels some of the atmospheric effects of astronomical seeing and makes very high precision measurements possible.

A groundbreaking study with the Palomar Testbed Interferometer [cite journal
author=G. van Belle "et al"
title=Altair's Oblateness and Rotation Velocity from Long-Baseline Interferometry
journal=Astrophysical Journal
year=2001 | volume=559 | pages=1155
url=http://adsabs.harvard.edu/abs/2001ApJ...559.1155V
accessdate=2008-07-29 ] revealed that the star Altair is not spherical, but is rather flattened at the poles due to its high rate of rotation.

External links

* [http://msc.caltech.edu/missions/Palomar/ Palomar Testbed Interferometer (PTI)] on the internet

References