The Habitable-zone Planet Finder: A status update on the development of a stabilized fiber-fed near-infrared spectrograph for the Hobby-Eberly telescope

摘要

The Habitable-Zone Planet Finder is a stabilized, fiber-fed, NIR spectrograph being built for the 10m Hobby-Eberly telescope (HET) that will be capable of discovering low mass planets around M dwarfs. The optical design of the HPF is a white pupil spectrograph layout in a vacuum cryostat cooled to 180 K. The spectrograph uses gold-coated mirrors, a mosaic echelle grating, and a single Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7-micron cutoff covering parts of the information rich z, Y and J NIR bands at a spectral resolution of R～50,000. The unique design of the HET requires attention to both near and far-field fiber scrambling, which we accomplish with double scramblers and octagonal fibers. In this paper we discuss and summarize the main requirements and challenges of precision RV measurements in the NIR with HPF and how we are overcoming these issues with technology, hardware and algorithm developments to achieve high RV precision and address stellar activity.