Amanda Sickafoose

SpUpNIC (Spectrograph Upgrade: Newly Improved Cassegrain) on the South African Astronomical Observatory's 74-inch telescope

SpUpNIC (Spectrograph Upgrade: Newly Improved Cassegrain) is the extensively upgraded Cassegrain Spectrograph on the South African Astronomical Observatorys 74-inch (1.9-m) telescope. The inverse-Cassegrain collimator mirrors and woefully inefficient Maksutov-Cassegrain camera optics have been replaced, along with the CCD and SDSU controller. All moving mechanisms are now governed by a programmable logic controller, allowing remote configuration of the instrument via an intuitive new graphical user interface. The new collimator produces a larger beam to match the optically faster Folded-Schmidt camera design and nine surface-relief diffraction gratings offer various wavelength ranges and resolutions across the optical domain. The new camera optics (a fused silica Schmidt plate, a slotted fold flat and a spherically figured primary mirror, both Zerodur, and a fused silica field-flattener lens forming the cryostat window) reduce the camera’s central obscuration to increase the instrument throughput. The physically larger and more sensitive CCD extends the available wavelength range; weak arc lines are now detectable down to 325 nm and the red end extends beyond one micron. A rear-of-slit viewing camera has streamlined the observing process by enabling accurate target placement on the slit and facilitating telescope focus optimisation. An interactive quick-look data reduction tool further enhances the user-friendliness of SpUpNI

SALT and SAAO strategy, focusing on the time-domain: process, plans, and challenges

The South African astronomical community together with the international SALT community recently completed a process to detail a science strategy for SALT, the 10m international telescope that SAAO operates. After six years of science operations, the telescope is a very cost-effective large telescope science producer. The strategy was adopted by the SALT Board, and has already resulted in funding choices for the next stage of instrumentation. The SALT strategy intertwines with that of the SAAO and South African optical astronomy in general. This paper outlines the process followed, the main motivations and plans for the next stage, including risks and challenges. This paper in particular concentrates on the plans to making SAAO/SALT a major player in time domain astrophysics, one of three adopted strategic science focus areas. Plans include a novel design for a high-efficiency spectrograph serving transient follow-up, for which South Africa is well positioned; advanced software aiming to make the whole mountain-top operate as a single transient machine; feasibility studies into revolutionizing SALT observations by utilizing the primary mirrors hundreds of square degree size uncorrected field-of-view. Other SPIE papers in this meeting describe these and other developments at SALT and SAAO in more detail

Design and results for the SAAO wide-field nasmyth camera

The South African Astronomical Observatory (SAAO) is currently developing WiNCam, the Wide-field Nasmyth Camera, to be mounted on Lesedi, the observatory’s new 1-metre telescope. This paper discusses the design and results for the remotely-operated camera system. The camera consists of an E2V-231-C6 Back Illuminated Scientific Charge Coupled Device (CCD) sensor with 6144x6160 pixels, four outputs operating in non-inverted mode. This is to date the largest single chip CCD-system developed at SAAO. The CCD is controlled with a modified Inter-University Centre for Astronomy and Astrophysics (IUCAA) Digital Sampler Array Controller (IDSAC) utilizing digital correlated double sampling. The camera system will have full-frame and frame-transfer read out modes available with sub-windowing and pre-binning abilities. Vacuum through-wall PCB technology is used to route signals through the vacuum interface between the controller and the CCD. A thin, compact, 125x125mm aperture, sliding-curtain-mechanism shutter was designed and manufactured together with a saddle-type filter-magazine-gripper system. The CCD is cryogenically cooled using a Stirling Cooler with active vibration cancellation; CCD temperature control is done with a Lake Shore Temperature Controller. A Varian Ion Pump and Activated Charcoal are used to maintain good vacuum and to prolong intervals between vacuum pump down. The various hardware components of the system are connected using distributed software architecture, and a web-based GUI allows remote and scripted operation of the instrument.

Taxonomy and Light-curve Data of 1000 Serendipitously Observed Main-belt Asteroids

We present VRI spectrophotometry of 1003 Main-Belt Asteroids (MBAs) observed with the Sutherland, South Africa, node of the Korea Microlensing Telescope Network (KMTNet). All of the observed MBAs were serendipitously captured in KMTNets large 2deg

The South African Astronomical Observatory instrumentation software architecture and the SHOC instruments

\times

A new alignment procedure for the South African Astronomical Observatory's 74-inch telescope

2deg field of view during a separate targeted near-Earth Asteroid study (Erasmus et al. 2017). Our broadband spectrophotometry is reliable enough to distinguish among four asteroid taxonomies and we confidently categorize 836 of the 1003 observed targets as either a S-, C-, X-, or D-type asteroid by means of a Machine Learning (ML) algorithm approach. Our data show that the ratio between S-type MBAs and (C+X+D)-type MBAs, with H magnitudes between 12 and 18 (12 km

The Structure of Chariklo’s Rings from Stellar Occultations

\gtrsim

The OmegaWhite survey for short-period variable stars – III: follow-up photometric and spectroscopic observations

diameter

SAAO's new robotic telescope and WiNCam (Wide-field Nasmyth Camera)

\gtrsim

Characterization of Near-Earth Asteroids Using KMTNET-SAAO

0.75 km), is almost exactly 1:1. Additionally, we report 0.5- to 3-hour (median: 1.3-hour) light-curve data for each MBA and we resolve the complete rotation periods and amplitudes for 59 targets. Two out of the 59 targets have rotation periods potentially below the theoretical zero cohesion boundary limit of 2.2 hours. We report lower limits for the rotation periods and amplitudes for the remaining targets. Using the resolved and unresolved light curves we determine the shape distribution for this population using a Monte Carlo simulation. Our model suggests a population with an average elongation