Tull Spectrograph

The Tull Spectrograph (TS2) is the workhorse instrument of HJST.  A high-resolution spectrometer available with two-pixel resolving powers in its two modes of operation are 60,000 (TS23) and 240,000 (TS21). Two echelle gratings offer minimum inter-order separations of 10.5 and 15.5 arcsec. At R = 60,000, data from the full bandwidth of 3,400–10,900 Å are collected with the TK2048 CCD in as few as two exposures. Co-addition is available. Remote field acquisition and guiding are available, and autoguiding is available.