HATSouth: A Global Network of Fully Automated Identical Wide-Field Telescopes1

Abstract

HATSouth is the world's first network of automated and homogeneous telescopes that is capable of year-round 24-hour monitoring of positions over an entire hemisphere of the sky. The primary scientific goal of the network is to discover and characterize a large number of transiting extrasolar planets, reaching out to long periods and down to small planetary radii. HATSouth achieves this by monitoring extended areas on the sky, deriving high precision light curves for a large number of stars, searching for the signature of planetary transits, and confirming planetary candidates with larger telescopes. HATSouth employs six telescope units spread over three prime locations with large longitude separation in the southern hemisphere (Las Campanas Observatory, Chile; HESS site, Namibia; Siding Spring Observatory, Australia). Each of the HATSouth units holds four 0.18 m diameter f/2.8 focal ratio telescope tubes on a common mount producing an 8.2 • × 8.2 • field-of-view on the sky, imaged using four 4K × 4K CCD cameras and Sloan r filters, to give a pixel scale of 3.7 ′′ pixel −1 . The HATSouth network is capable of continuously monitoring 128 square arc-degrees at celestial positions moderately close to the anti-solar direction. We present the technical details of the network, summarize operations, and present detailed weather statistics for the three sites. Robust operations have meant that on average each of the six HATSouth units has conducted observations on ∼ 500 nights over a two-year time period, yielding a total of more than 1 million science frames at four minute integration time, and observing ∼ 10.65 hours per day on average. We describe the scheme of our data transfer and reduction from raw pixel images to trend-filtered light curves and transiting planet candidates. Photometric precision reaches ∼ 6 mmag at 4 minute cadence for the brightest non-saturated stars at r ≈ 10.5. We present detailed transit recovery simulations to determine the expected yield of transiting planets from HATSouth. We highlight the advantages of networked operations, namely, a threefold increase in the expected number of detected planets, as compared to all telescopes operating from the same site.

HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b: Four Warm Giant Planets Transiting K Dwarfs*

“…gamma-ray observatory in Namibia, and Siding Spring Observatory (SSO) in Australia. The operations and observing procedures of the network were described by Bakos et al (2013), while the method for reducing the images to trend-filtered light curves and searching for candidate transiting planets were described by Penev et al (2013). We note that the trend-filtering makes use of the Trend-Filtering Algorithm (TFA) of Kovács et al (2005), while transit signals are detected using the Box-fitting Least Squares (BLS) method of Kovács et al (2002).…”

HATS-8b: A LOW-DENSITY TRANSITING SUPER-NEPTUNE

“…Although some data were acquired as early as 2009 September, the bulk of the observations, over 10,000 images, were taken between 2011 March and August (see Table 1). Details of the HATSouth imaging system can be found in Bakos et al (2013) and Penev et al (2013), while here we provide a summary of the critical features. HATSouth employs Takahashi astrographs ( f 2.8, 18 cm apertures) imaged onto Apogee U16M 4 K 4 Ḱ cameras.…”

HATS-3b: AN INFLATED HOT JUPITER TRANSITING AN F-TYPE STAR

“…Details relating to the observation, reduction, and analysis of the HATSouth photometric discovery data are fully described in Bakos et al (2013). Here, we provide a brief summary of the salient points.…”