Lowell Observatory

Lowell's astronomers carry out research in areas spanning much of modern astrophysics, from studies of tiny icy objects in our own solar system to the structure of distant galaxies. Meet our scientists and learn more about our diverse programs here.

High Precision Orbits of Binary Stars
Larry Wasserman and Otto Franz

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Larry Wasserman

Larry Wasserman, in collaboration with Lowell astronomer Otto Franz, applies his interest in ephemeris calculation to the orbits of relatively close (less than a few tenths of an arcsec), low-mass binary stars. Here, the Lowell Observatory colleagues are interested in obtaining accurate masses of low-mass stars. The binaries are observed with the Fine Guidance Sensor on HST which enables them to measure the separation of the binary to a precison of about milliarcsec and the position angle to a precision of 0.1 deg, even for stars with a difference in brightness of several magnitudes.