We present a status update on SCORPIO, the next facility instrument for the Gemini South telescope at Cerro Pachon, Chile. SCORPIO is now in advanced Assembly, Integration and Verification phase at SWRI (San Antonio) and LICA (Madrid) in anticipation of shipment to Chile by Fall-2025.

There are currently many large-field surveys that are operational and are being planned including the powerful Vera C. Rubin Observatory Legacy Survey of Space and Time. These surveys will increase the number and diversity of transients dramatically. However, for some transients, like supernovae (SNe), we can gain more understanding by directed observations (e.g., shock breakout and γ -ray detections) than by simply increasing the sample size. For example, the initial emission from these transients can be a powerful probe of these explosions. Upcoming ground-based detectors are not ideally suited to observing the initial emission (shock emergence) of these transients. These observations require a large field-of-view X-ray mission with a UV follow-up within the first hour of shock breakout. The emission in the first 1 hr to even 1 day provides strong constraints on the stellar radius and asymmetries in the outer layers of stars, the properties of the circumstellar medium (e.g., inhomogeneities in the wind for core-collapse SNe and accreting companions in thermonuclear SNe), and the transition region between these two areas. This paper describes a simulation for the number of SNe that could be seen by a large field-of-view lobster-eye X-ray and UV observatory.

SCORPIO (Spectrograph and Camera for the Observation of Rapid Phenomena in the Infrared and Optical) is a multiband instrument covering 0.385um to 2.35um in spectroscopy and 0.400um to 2.35um in imaging, currently under development for the Gemini Observatory. The instrument is intended to be deployed as a facility instrument at Gemini South in Chile to enable detailed follow-up observations of transients detected by the Vera C. Rubin Observatory. The instrument is designed with eight parallel channels corresponding to the standard g, r, i, z, Y, J, H, and Ks passbands. Here we present an update on the status of the instrument, the data reduction software, and the current path forward to completion.

The Multi-spectral Visible Imaging Camera (MVIC) detector is a time-delay and integration (TDI) CCD with 4, 8, 16, 32, and 64 TDI modes. MVIC is scheduled to fly as part of the instrument suite on the Lucy mission to the Trojans launching in 2021. We present here the pre-delivery SwRI Detector Characterization Lab (SDCL) data of the Flight (FM) and Flight Spare (FS) from 370 to 925nm. The MVIC sensor consists of six broad-band top-hat filters on a single sapphire substrate developed by VIAVI Solutions and six CCDs on a single wafer developed by Semiconductor Technology Associates (STA). We have calibrated both the FS and FM for read noise, dark current, linearity, quantum efficiency, and total system throughput. The data were collected using standard Photon Transfer Curve techniques at strategically chosen wavelengths corresponding to center and edge of the bandpass filters. Each system was also calibrated for spuriously operational pixels and cosmetic defects. The pixel response function is mapped on a pixel-by-pixel basis for the 64 TDI mode.

SCORPIO is the next facility instrument for the Gemini South telescope at Cerro Pachon, Chile. SCORPIO's main science driver is the detection and monitoring of faint time-domain events, in particular the follow-up of discoveries by the Vera C. Rubin Observatory, but it can also carry out with unique efficiency a large variety of astrophysical programs. The instrument has recently passed Critical Design Review and is now in its Assembly, Integration and Verification phase. In this paper we provide an updated overview of the final instrument design and the main performance parameters in light of the science drivers.