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.
MASCARA-4 b is a hot Jupiter in a highly-misaligned orbit around a rapidly-rotating A3V star that was observed for 54 days by the Transiting Exoplanet Survey Satellite (TESS ). We perform two analyses of MASCARA-4 b using a stellar gravity-darkened model. First, we measure MASCARA-4 b's misaligned orbital configuration by modeling its TESS photometric light curve. We take advantage of the asymmetry in MASCARA-4 b's transit due to its host star's gravity-darkened surface to measure MASCARA-4 b's true spin-orbit angle to be 104 •+7 • −13 • . We also detect a ∼ 4σ secondary eclipse at 0.491 ± 0.007 orbital phase, proving that the orbit is slightly eccentric. Second, we model MASCARA-4 b's insolation including gravity-darkening and find that the planet's received XUV flux varies by 4% throughout its orbit. MASCARA-4 b's short-period, polar orbit suggests that the planet likely underwent dramatic orbital evolution to end up in its present-day configuration and that it receives a varying stellar irradiance that perpetually forces the planet out of thermal equilibrium. These findings make MASCARA-4 b an excellent target for follow-up characterization to better understand orbital evolution and current-day of planets around high-mass stars.
We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design builds upon our past optical SETI experiences, and is the first step toward a new, more versatile and sophisticated generation of very fast optical and near-infrared pulse search devices. We present our instrumental design by giving an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. This project makes use of near-infrared (950 -1650 nm) discrete amplification Avalanche Photodiodes (APD) that have > 1 GHz bandwidths with low noise characteristics and moderate gain (~10 4 ). We have investigated the use of single versus multiple detectors in our instrument (see Maire et al., this conference), and have optimized the system to have both high sensitivity and low false coincidence rates. Our design is optimized for use behind a 1m telescope and includes an optical camera for acquisition and guiding. A goal is to make our instrument relatively economical and easy to duplicate. We describe our observational setup and our initial search strategies for SETI targets, and for potential interesting compact astrophysical objects.
The near-infrared region offers a compelling window for interstellar communications, energy transfer, and transient detection due to low extinction and low thermal emission from dust. We have conducted a search for near-infrared (950-1650 nm) light pulses having durations less than 50 nanoseconds while observing 1280 astronomical objects which include a wide range of nearby stars, clusters, and galaxies. A field of view of 2 5 × 2 5 for a duration of at least 300 s was observed for each object pointing. These observations were made using the latest Near-InfraRed Optical SETI instrumentation on the Nickel telescope (1 m) at Lick Observatory. Equipped with two detectors collecting photons coming from the same part of the sky, the instrument is aimed at detecting light pulses coincident between them within nanoseconds, as well as periodic signals. While we report on a few notifications from our system, we believe these events were consistent with the statistical noise of our data. No significant evidence for repeated near-infrared nanosecond pulsed signal was found, given the instrumental limit in sensitivity of 63 ph m −2 ns −1 .
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