We present overall specifications and science goals for a new optical and near-infrared (350 - 1650 nm) instru- ment designed to greatly enlarge the current Search for Extraterrestrial Intelligence (SETI) phase space. The Pulsed All-sky Near-infrared Optical SETI (PANOSETI) observatory will be a dedicated SETI facility that aims to increase sky area searched, wavelengths covered, number of stellar systems observed, and duration of time monitored. This observatory will offer an “all-observable-sky” optical and wide-field near-infrared pulsed tech- nosignature and astrophysical transient search that is capable of surveying the entire northern hemisphere. The final implemented experiment will search for transient pulsed signals occurring between nanosecond to second time scales. The optical component will cover a solid angle 2.5 million times larger than current SETI targeted searches, while also increasing dwell time per source by a factor of 10,000. The PANOSETI instrument will be the first near-infrared wide-field SETI program ever conducted. The rapid technological advance of fast-response optical and near-infrared detector arrays (i.e., Multi-Pixel Photon Counting; MPPC) make this program now feasible. The PANOSETI instrument design uses innovative domes that house 100 Fresnel lenses, which will search concurrently over 8,000 square degrees for transient signals (see Maire et al. and Cosens et al., this conference). In this paper, we describe the overall instrumental specifications and science objectives for PANOSETI.
We propose a novel instrument design to greatly expand the current optical and near-infrared SETI search pa- rameter space by monitoring the entire observable sky during all observable time. This instrument is aimed to search for technosignatures by means of detecting nano- to micro-second light pulses that could have been emitted, for instance, for the purpose of interstellar communications or energy transfer. We present an instru- ment conceptual design based upon an assembly of 198 refracting 0.5-m telescopes tessellating two geodesic domes. This design produces a regular layout of hexagonal collecting apertures that optimizes the instrument footprint, aperture diameter, instrument sensitivity and total field-of-view coverage. We also present the optical performance of some Fresnel lenses envisaged to develop a dedicated panoramic SETI (PANOSETI) observatory that will dramatically increase sky-area searched (pi steradians per dome), wavelength range covered, number of stellar systems observed, interstellar space examined and duration of time monitored with respect to previous optical and near-infrared technosignature finders.
KPF is a fiber-fed, high-resolution, high-stability spectrometer in development at the UC Berkeley Space Sciences Laboratory for the W.M. Keck Observatory. The instrument is designed to characterize exoplanets via Doppler spectroscopy with a single measurement precision of 0.5ms-1 or better, however its resolution and stability will enable a wide variety of astrophysical pursuits. KPF will have a 200mm collimated beam diameter and a resolving power of >80,000. The design includes a green channel (440nm to 590 nm) and red channel (590nm to 850 nm). A novel design aspect of KPF is the use of a Zerodur optical bench, and Zerodur optics with integral mounts, to provide stability against thermal expansion and contraction effects.
Over the last two decades, Optical Search for Extra-Terrestrial Intelligence experiments have been conducted to search for either continuous or pulsed visible-light laser beacons that could be used for interstellar communication or energy transmission. Near-infrared offers a compelling window for signal transmission since there is a decrease in interstellar extinction and Galactic background compared to optical wavelengths. An innovative Near-InfraRed and Optical SETI (NIROSETI) instrument has been designed and constructed to take advantage of a new generation of fast (> 1 Ghz) low-noise near-infrared avalanche photodiodes to search for nanosecond pulsed near-infrared (850 - 1650 nm) pulses. The instrument was successfully installed and commissioned at the Nickel (1m) telescope at Lick Observatory in March 2015. We will describe the overall design of the instrument with a focus on methods developed for data acquisition and reduction for near-infrared SETI. Time and height analyses of the pulses produced by the detectors are performed to search for periodicity and coincidences in the signals. We will further discuss our NIROSETI survey plans.
KEYWORDS: Stars, Planets, Exoplanets, Space operations, Satellites, Cameras, Charge-coupled devices, Space telescopes, James Webb Space Telescope, Observatories
The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its 2-year mission, TESS will employ four wide-field optical charge-coupled device cameras to monitor at least 200,000 main-sequence dwarf stars with IC≈4−13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from 1 month to 1 year, depending mainly on the star’s ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10 to 100 times brighter than those surveyed by the pioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every 4 months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations.
KEYWORDS: Stars, Planets, Space operations, Cameras, Charge-coupled devices, Space telescopes, Exoplanets, Observatories, James Webb Space Telescope, Sensors
The Transiting Exoplanet Survey Satellite (TESS ) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with IC (approximately less than) 13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler mission. This will make TESS planets easier to characterize with follow-up observations. TESS is expected to find more than a thousand planets smaller than Neptune, including dozens that are comparable in size to the Earth. Public data releases will occur every four months, inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the nearest and brightest stars hosting transiting planets, which will endure as highly favorable targets for detailed investigations.
A Search for Extraterrestrial Life (SETI), based on the possibility of interstellar communication via laser signals, is being designed to extend the search into the near-infrared spectral region (Wright et al, this conference). The dedicated near-infrared (900 to 1700 nm) instrument takes advantage of a new generation of avalanche photodiodes (APD), based on internal discrete amplification. These discrete APD (DAPD) detectors have a high speed response (< 1 GHz) and gain comparable to photomultiplier tubes, while also achieving significantly lower noise than previous APDs. We are investigating the use of DAPD detectors in this new astronomical instrument for a SETI search and transient source observations. We investigated experimentally the advantages of using a multiple detector device operating in parallel to remove spurious signals. We present the detector characterization and performance of the instrument in terms of false positive detection rates both theoretically and empirically through lab measurements. We discuss the required criteria that will be needed for laser light pulse detection in our experiment. These criteria are defined to optimize the trade between high detection efficiency and low false positive coincident signals, which can be produced by detector dark noise, background light, cosmic rays, and astronomical sources. We investigate experimentally how false coincidence rates depend on the number of detectors in parallel, and on the signal pulse height and width. We also look into the corresponding threshold to each of the signals to optimize the sensitivity while also reducing the false coincidence rates. Lastly, we discuss the analytical solution used to predict the probability of laser pulse detection with multiple detectors.
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 (~104). 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.
ACCESS is one of four medium-class mission concepts selected for study in 2008-9 by NASA's Astrophysics Strategic
Mission Concepts Study program. ACCESS evaluates a space observatory designed for extreme high-contrast imaging
and spectroscopy of exoplanetary systems. An actively-corrected coronagraph is used to suppress the glare of diffracted
and scattered starlight to contrast levels required for exoplanet imaging. The ACCESS study considered the relative
merits and readiness of four major coronagraph types, and modeled their performance with a NASA medium-class space
telescope. The ACCESS study asks: What is the most capable medium-class coronagraphic mission that is possible with
telescope, instrument, and spacecraft technologies available today? Using demonstrated high-TRL technologies, the
ACCESS science program surveys the nearest 120+ AFGK stars for exoplanet systems, and surveys the majority of
those for exozodiacal dust to the level of 1 zodi at 3 AU. Coronagraph technology developments in the coming year are
expected to further enhance the science reach of the ACCESS mission concept.
ACCESS (Actively-Corrected Coronagraph for Exoplanet System Studies) develops the science and engineering case for
an investigation of exosolar giant planets, super-earths, exo-earths, and dust/debris fields that would be accessible to a
medium-scale NASA mission. The study begins with the observation that coronagraph architectures of all types (other
than the external occulter) call for an exceptionally stable telescope and spacecraft, as well as active wavefront
correction with one or more deformable mirrors (DMs). During the study, the Lyot, shaped pupil, PIAA, and a number
of other coronagraph architectures will all be evaluated on a level playing field that considers science capability
(including contrast at the inner working angle (IWA), throughput efficiency, and spectral bandwidth), engineering
readiness (including maturity of technology, instrument complexity, and sensitivity to wavefront errors), and mission
cost so that a preferred coronagraph architecture can be selected and developed for a medium-class mission.
SIM is a space astrometric interferometer capable of better than one-microarcsecond ( as) single measurement accuracy,
providing the capability to detect stellar "wobble" resulting from planets in orbit around nearby stars. While a search for
exoplanets can be optimized in a variety of ways, a SIM five-year search optimized to detect Earth analogs (0.3 to 10
Earth masses) in the middle of the habitable zone (HZ) of nearby stars would yield the masses, without M*sin(i)
ambiguity, and three-dimensional orbital parameters for planets around ~70 stars, including those in the HZ and further
away from those same stars. With >200 known planets outside our solar system, astrophysical theorists have built
numerical models of planet formation that match the distribution of Jovian planets discovered to date and those models
predict that the number of terrestrial planets (< 10 M(+) ) would far exceed the number of more massive Jovian planets.
Even so, not every star will have an Earth analog in the middle of its HZ. This paper describes the relationship between
SIM and other planet detection methods, the SIM planet observing program, expected results, and the state of technical
readiness for the SIM mission.
Eclipse is a proposed Discovery-class mission to perform a sensitive imaging survey of nearby planetary systems, including a complete survey for Jupiter-sized planets orbiting 5 AU from all stars of spectral types A-K to distances of 15 pc. Eclipse is a coronagraphic space telescope concept designed for high-contrast visible wavelength imaging and spectrophotometry. Its optical design incorporates essential elements: a telescope with an unobscured aperture of 1.8 meters and optical surfaces optimized for smoothness at critical spatial frequencies, a coronagraphic camera for suppression of diffracted light, and precision active optical correction for suppression of light scattered by residual mirror surface irregularities. For reference, Eclipse is predicted to reduce diffracted and scattered starlight between 0.25 and 2.0 arcseconds from the star by at least three orders of magnitude compared to any HST instrument. The Eclipse mission offers precursor science explorations and critical technology validation in
support of coronagraphic concepts for NASA's Terrestrial Planet Finder (TPF). A baseline three-year science mission would provide a survey of the nearby stars accessible to TPF before the end of this decade, promising fundamental new insights into the nature and evolution of possibly diverse planetary systems associated with our Sun's nearest neighbors.
Dan Werthimer, David Anderson, C. Stuart Bowyer, Jeff Cobb, Eric Heien, Eric Korpela, Michael Lampton, Matt Lebofsky, Geoff Marcy, Meghan McGarry, Dick Treffers
KEYWORDS: Sensors, Observatories, Telescopes, Radio optics, Stars, Space telescopes, Planets, Signal detection, Electromagnetic coupling, Computing systems
We present results from two radio and two optical SETI programs at the University of California, Berkeley: The SERENDIP IV sky survey searches for narrow band radio signals at the 305 meter Arecibo Observatory in Puerto Rico. The program uses a 168 million channel spectrum analyser, running in 'piggyback' mode, using a dedicated receiver to take data 24 hours a day, year round. SETIhome is Berkeley's most recent SETI project. SETIhome uses desktop computers of over a million volunteers to analyse 40 Terabytes of data from Arecibo Observatory. SETIhome is the largest supercomputer on the planet, currently averaging 20 Teraflops. The SEVENDIP optical program searches for nS timescale pulses at visible wavelengths. The target list includes nearby F,G,K and M stars, plus a few globular cluster and galaxies. The pulse search utilizes Berkeley's 30 inch automated telescope at Leuschner Observatory. Another Berkeley optical SETI program searches for narrow band coherent signals in high resolution stellar spectra taken by Marcy and his colleagues as part of their on-going search for planets at Lick, Keck, and the Anglo-Australian observatories.
The first three extrasolar planets orbiting Solar-like stars have recently been discovered. All three were inferred from a periodicity in the optical Doppler measurements of their host stars, indicating a reflex motion in response to the gravitational force exerted by the planets. From such measurements and standard Newtonian physics, one may infer the orbital period and value of MPL sin i of 0.46, 2.5 and 6.5 MJUP, and orbital periods of 4.2, 117 and 1100 days, respectively. The most massive planet (around 70 Vir) has an eccentricity, e equals 0.38, larger than any in our Solar System, and one (around 51 Peg) has an orbital radius of 0.05 AU which is smaller than any in our Solar System. A general theory for the formation of planets must include these new characteristics.
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