The S-PLUS survey is described in detail in Mendes de Oliveira et al. (2019). In this page we describe the Main Survey (MS) and the other 4 sub-surveys: the Ultra-Short Survey (USS), the Galactic Survey (GS), the Marble Field Survey (MFS) and the Variability Fields Survey (VFS).
The Main Survey (MS)
Covering an area of ~8000 deg2 with a single visit to each field per filter, under photometric conditions and when the seeing ranges from 0.8’’ to 2.0”. The MS strategy is motivated by the requirements set by the extragalactic science, with accurate photometric redshifts for objects down to i = 21 (Molino et al., in prep.), allowing the study of the local large-scale structure, star formation rates and stellar populations.
The Ultra-Short Survey (USS)
The Galactic Survey (GS)
Covers the same area of the MS, in 12 bands, but with 5s exposures. The USS is motivated by the search for low-metallicity and carbon-enhanced stars. The USS is performed in gray non-photometric nights and bright time, under any seeing conditions.
Covers an area of 1300 deg2 in the Milky Way plane in all 12 filters including two Galactic regions, the bulge and the disk. The first epoch of the GS will have the MS depth, followed by shallow 2nd and 3rd epoch data having exposure times of 1 s and 5 s, respectively, and only using the filters r, i and F660. Finally, the GS will obtain at least 25 more epochs at random cadence and over many years, at the same depth as the first epoch observations. These various exposure times will probe a large range of magnitudes, allowing the sampling of different stellar populations while the temporal aspect of the survey is suitable to the detection of variable sources.
The Marble Field Survey (MFS)
The Variability Fields Survey (VFS)
Composed by a set of specific fields that will be revisited as often as possible under dark or gray nights, and photometric or close-to-photometric weather conditions, when the seeing is too poor to observe MS, i.e. worse than 2’’. Objects selected for the MFS at the time of this writing are the Large and Small Magellanic Clouds (LMC and SMC), M83 (only in the narrow bands), the Dorado Group and the Hydra cluster. The MFS will primarily be suitable for identification and characterization of variable stars, studies of galaxies using techniques similar to low-resolution IFU observations, and the detection of stellar and gas halos or streams out to several effective radii around nearby galaxies.
We will perform observations with exposure times to be determined, repeated with a cadence that is set by the frequency of non-photometric nights, covering a number of fields already observed by MS. The exact strategy for the VFS is still not set, given that proposals for the use of VFS are still to be received by the team. The VFS may be suitable to detect variable sources, such as pulsating stars, cataclysmic variables, supernovae (SNe), eclipsing binaries, asteroids, AGNs, and to find and do follow-up of targets of opportunity.