Early science results from the Hobby-Eberly Telescope

We present science results from the first four months of early operations of the Hobby-Eberly Telescope (HET). During this period the HET was used for science approximately two weeks per month centered on new moon. We discuss the types of science program that are best suited to the unique nature of the HET and give examples of surveys and synoptic observations that are ongoing. The Marcario Low Resolution Spectrograph is the only facility instrument currently in service, so the science results from this instrument are emphasized. Future facility instruments are briefly discussed, along with a description of current HET performance. The HET is a unique telescope that is the prototype for a new generation of cost-effective large telescopes. It has a unique tilted-Arecibo design that is able to access a wide range of declinations by rotating the telescope structure in azimuth. A star tracker follows objects for between 40 minutes and 2.5 hours, depending on declination. These physical constraints make it essential that observations be carefully planned and that the HET be queue-scheduled. Currently, the HET is regularly delivering science observations in queue-scheduled mode, but image quality is typically between 2.0 and 3.0 arcsec, due to thermally-driven primary mirror stack degradation and dome seeing. These problems are being addressed by the primary mirror edge sensor project and by removing heat sources from the tracker prime focus instrument package, and we expect to be delivering images within the 1 arcsecond specification in 2001.