bRing: An observatory dedicated to monitoring the β Pictoris b Hill sphere transit

Abstract

Aims. We describe the design and first light observations from the β Pictoris b Ring ("bRing") project. The primary goal is to detect photometric variability from the young star β Pictoris due to circumplanetary material surrounding the directly imaged young extrasolar gas giant planet β Pictoris b. Methods. Over a nine month period centred on September 2017, the Hill sphere of the planet will cross in front of the star, providing a unique opportunity to directly probe the circumplanetary environment of a directly imaged planet through photometric and spectroscopic variations. We have built and installed the first of two bRing monitoring stations (one in South Africa and the other in Australia) that will measure the flux of β Pictoris, with a photometric precision of 0.5% over 5 min. Each station uses two wide field cameras to cover the declination of the star at all elevations. Detection of photometric fluctuations will trigger spectroscopic observations with large aperture telescopes in order to determine the gas and dust composition in a system at the end of the planet-forming era. Results. The first three months of operation demonstrate that bRing can obtain better than 0.5% photometry on β Pictoris in five minutes and is sensitive to nightly trends enabling the detection of any transiting material within the Hill sphere of the exoplanet.

Transiting exocomets detected in broadband light by TESS in the β Pictoris system

“…Future work includes a more comprehensive modelling of all the transits seen in the TESS light curve, and a study of whether high resolution spectral observations were taken simultaneously with this transit to confirm the cometary hypothesis. A comprehensive photometric campaign was conducted during the Hill sphere transit of β Pictoris b (Kenworthy 2017), which includes bRing (Stuik et al 2017), ASTEP (Guillot et al 2015;Abe et al 2013;Mékarnia et al 2017), and BRITE-Constellation (Weiss et al 2014) photometry. Searching this data may yield more candidate broadband transits.…”

MASCARA-4 b/bRing-1 b: A retrograde hot Jupiter around a bright A-type star

“…It has so far found MASCARA-1 b (Talens et al 2018a), MASCARA 2-b (Talens et al 2018b), and MASCARA 3-b (Hjorth et al 2019). MASCARA is combined with the bRing network (Stuik et al 2017), which is based on similar technology to that used by MASCARA. The main science goal of bRing is to study the Hillsphere transit of β Pictoris b (Mellon et al 2019a;Kalas et al 2019); bRing has also been used for exoplanet transit searches (this work) and variable star characterization (e.g., Mellon et al 2019b,c).…”

Bright Southern Variable Stars in the bRing Survey

“…Each camera had an FLI 4008×2672 pixel CCD and f=1.4 mm Canon wide-angle lens, which resulted in a total field of view of 74°×53°with a pointing optimized for β Pictoris (δ;−53°). Exposure times were alternated between 6.4 and 2.54 s; these were subsequently coadded and binned to 5 minute samplings and saved to disk (Stuik et al 2017;Talens et al 2018).…”

“…In 2017, the β Pictoris b Ring (bRing) instruments (located in South Africa and Australia) were constructed and brought online to observe the 2017-2018 transit of the β Pictoris b Hill sphere (Stuik et al 2017;Kalas et al 2019;Mellon et al 2019b). While observing β Pictoris, bRing captured nearly continuous photometry of 10,000+ bright stars (V∼4-8 mag) in the southern sky (δ−30°).…”