* Astronomy

Title: Precision Astrometry of the Exoplanet Host Candidate GD 66
Authors: J. Farihi, J. P. Subasavage, E. P. Nelan, H. C. Harris, C. C. Dahn, J. Nordhaus, D. S. Spiegel

The potential existence of a giant planet orbiting within a few AU of a stellar remnant has profound implications for both the survival and possible regeneration of planets during post-main sequence stellar evolution. This paper reports Hubble Space Telescope Fine Guidance Sensor and U.S. Naval Observatory relative astrometry of GD 66, a white dwarf thought to harbour a giant planet between 2 and 3 AU based on stellar pulsation arrival times. Combined with existing infrared data, the precision measurements here rule out all stellar-mass and brown dwarf companions, implying that only a planet remains plausible, if orbital motion is indeed the cause of the variations in pulsation timing.

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