VIRUS (Visible Integral-field Replicable Unit Spectrograph) Instrument Summary

  • Low scattered light

  • Predicted 50% peak throughput on the sky

  • Growing on a weekly/monthly basis as new spectrographs are finished and can be integrated into the system (78 when complete).

  • VIRUS spectrographs cover 3500-5500A with R~700 (R=670 at 3900A, 850 at 4600A, and 990 at 5200A).

  • Fibers are 1.5" diameter, IFUs are 50"x50" on the sky, separated by 50" (a 3-point dither fills in most of the intra-IFU space; a 4-point tiling of these dithered observations fills in most of the inter-IFU space).

  • Total field of view is 16'x16'.

  • For target acquisition and auto-guiding notes, see the performance page

  • For further technical details about VIRUS, see:

    Last updated: Sat, 30 Dec 2023 02:21:55 +0000 stevenj


The Telescope

Technical Overview

Object Observability


Non-sidereal observations



LRS2 Summary

LRS2 Details

LRS2 Fiber Layout and Position Angle

LRS2 Throughput

LRS2 Observing details


VIRUS - Summary

VIRUS - Setting up on targets

VIRUS - Misc details

VIRUS - Throughput and sensitivity

VIRUS - low surface brightness sensitivity

VIRUS - Dithers, IFUs, Tiling

VIRUS - Tiling observations

Habitable Zone Planet Finder (HPF)

HPF Details

HPF Setting up on targets

HPF Throughput and Exposure Meter

HPF Data Reductions

HRS-2 (in development)

HRS-2 Summary

HRS-2 Details

HRS-2 configurations

HRS-2 exposure meter

HRS-2 Position Angle and Fiber layout

HRS-2 Throughput

Old Instruments

HRS - old

LRS - old

MRS - old

Program Preparation

Web Management System