SkyMapper

SkyMapper
Name	SkyMapper
Caption	SkyMapper telescope at Siding Spring Observatory
Organization	Research School of Astronomy and Astrophysics
Location	Siding Spring Observatory, New South Wales, Australia
Established	2008 (commissioning 2009)
Telescope type	Wide-field Schmidt
Aperture	1.35 m
Instrument	CCD camera

SkyMapper is a wide-field optical survey telescope located at Siding Spring Observatory operated by the Research School of Astronomy and Astrophysics. It conducts an all-southern-sky imaging survey that supports research across stellar astrophysics, extragalactic astronomy, cosmology, and time-domain science. The project involves collaborations among Australian institutions and international partners, providing publicly released imaging datasets used by researchers worldwide.

Overview

SkyMapper was conceived to produce a comprehensive photometric and astrometric map of the southern celestial hemisphere, complementing northern surveys such as Sloan Digital Sky Survey and enabling follow-up for facilities like Anglo-Australian Telescope and Australian Square Kilometre Array Pathfinder. The facility is situated at Siding Spring Observatory near Coonabarabran in New South Wales, leveraging local infrastructure shared with instruments including UK Schmidt Telescope and ANU 2.3 m Telescope. The survey strategy was influenced by previous projects such as Pan-STARRS, Gaia, and Dark Energy Survey and coordinates with programs at European Southern Observatory and Cerro Tololo Inter-American Observatory.

Telescope and Instrumentation

The SkyMapper telescope is a 1.35-metre modified Schmidt design built by the ANU Research School of Astronomy and Astrophysics with optical components manufactured by firms linked to projects like Subaru Telescope and Gemini Observatory. Its instrument suite centers on a 268-megapixel mosaic CCD camera developed in collaboration with teams experienced on DECam, CFHT MegaCam, and VST OmegaCAM. The filter set includes custom uvgriz bands inspired by SDSS ugriz and tailored to stellar parameter estimation used by missions such as Gaia and Hipparcos. The mechanical design integrates control systems analogous to those at Mount Stromlo Observatory and electronics influenced by European Space Agency instrumentation standards. Environmental and dome systems are coordinated with Australian Astronomical Observatory practices.

Survey and Observations

SkyMapper's primary program, the Southern Sky Survey, planned multi-epoch imaging across the entire southern sky in six filters to depths comparable with legacy surveys like SDSS and to complement time-domain efforts by Zwicky Transient Facility and All-Sky Automated Survey for Supernovae. Observing strategies include cadences for transient detection used by collaborators on LIGO-Virgo follow-up, and targeted programs for identification of metal-poor stars comparable to searches led by Hamburg/ESO Survey and RAVE. Survey fields overlap with footprints of 2MASS, WISE, GALEX, and ROSAT enabling multi-wavelength science. Calibration campaigns referenced standards from Landolt, Stetson, and external tie-ins to Pan-STARRS1 photometry.

Data Processing and Release

Data reduction pipelines for SkyMapper were developed drawing on software concepts from IRAF, Astropy, and processing frameworks used by LSST and DES. The pipeline performs bias subtraction, flat-fielding, astrometric solutions referenced to Gaia DR1 and later releases, and photometric calibration cross-matched against catalogs such as APASS and UCAC. Early public data releases paralleled community practices from SDSS Data Release 8 and Gaia incremental releases, with metadata and catalog access coordinated via archival infrastructures used by NASA/IPAC, CDS, and the International Virtual Observatory Alliance. Quality assurance borrowed techniques developed for Hubble Space Telescope pipeline validation and Chandra X-ray Observatory calibration.

Scientific Discoveries and Contributions

SkyMapper has contributed to the discovery of extremely metal-poor stars in the halo, influencing studies related to the First stars and chemical evolution traced in works connected to Frebel, Beers, and follow-up using Magellan Telescopes and Very Large Telescope. The survey enabled identification of nearby brown dwarfs and late-type dwarfs, complementing searches by WISE and confirmed with spectroscopy from Keck Observatory and Gemini South. Time-domain outputs aided transient characterization for supernovae studies tied to teams like Carnegie Supernova Project and played roles in electromagnetic follow-up for GW170817-related campaigns coordinated with LIGO partners. SkyMapper data have been used in galaxy evolution analyses overlapping investigations by GAMA and mass-mapping efforts similar to CFHTLenS. Photometric catalogs informed stellar population work relevant to Large Magellanic Cloud structure, linked to research by OGLE and MACHO teams.

Collaboration and Operations

SkyMapper operations are led by the Australian National University with partnerships involving institutions such as Monash University, University of Sydney, University of Western Australia, and international collaborators tied to Max Planck Institute for Astronomy and Carnegie Institution for Science. Funding and governance have intersected with agencies like the Australian Research Council and collaborations with instrumentation groups experienced from projects like DECam and Pan-STARRS. The project engages with community initiatives including the Virtual Observatory and regional networks coordinating target-of-opportunity follow-up across facilities like ANU 2.3 m, Magellan, and Gemini South. Educational and outreach efforts connect with public programs at Siding Spring Observatory Visitor Centre and undergraduate training at ANU Research School of Astronomy and Astrophysics.

Category:Astronomical surveys Category:Telescopes in Australia Category:Optical telescopes