Detecting a Nicoll-Dyson Beam

Detecting the Ultimate Power in the Universe with LSST

Authors:

Lund

Abstract:
Large time-domain surveys, when of sufficient scale, provide a greatly increased probability of detecting rare and, in many cases, unexpected events. Indeed, it is these unpredicted and previously unobserved objects that can lead to some of the greatest leaps in our understanding of the cosmos. The events that may be monitored include not only those that help contribute to our understanding of sources astrophysical variability, but may also extend to the discovery and characterization of civilizations comprised of other sentient lifeforms in the universe. In this paper we examine if the Large Synoptic Survey Telescope (LSST) will have the ability to detect the immediate and short-term effects of a concave dish composite beam superlaser being fired at an Earth analog from an alien megastructure.

Do not look into laser with remaining civilizaion.

SETI Search for Optical Flashes From KIC 846285 Turns up Negative

A Search for Brief Optical Flashes Associated with the SETI Target KIC 846285

Authors:

Abeysekara et al

Abstract:

The F-type star KIC~8462852 has recently been identified as an exceptional target for SETI (search for extraterrestrial intelligence) observations. We describe an analysis methodology for optical SETI, which we have used to analyse nine hours of serendipitous archival observations of KIC~8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon per m^2, is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.

Optical SETI Observations of the Anomalous Star KIC 8462852

Optical SETI Observations of the Anomalous Star KIC 8462852

Authors:

Schuetz et al

Abstract:

To explore the hypothesis that KIC 8462852's aperiodic dimming is caused by artificial megastructures in orbit (Wright et al. 2015), rather than a natural cause such as cometary fragments in a highly elliptical orbit (Marengo et al. 2015), we searched for electromagnetic signals from KIC 8462852 indicative of extraterrestrial intelligence. The primary observations were in the visible optical regime using the Boquete Optical SETI Observatory in Panama. In addition, as a preparatory exercise for the possible future detection of a candidate signal (Heidmann 1991), three of six observing runs simultaneously searched radio frequencies at the Allen Telescope Array in California. No periodic optical signals greater than 67 photons/m2 within a time frame of 25 ns were seen. This limit corresponds to isotropic optical pulses of 8E22 joules. If, however, any inhabitants of KIC 8462852 were targeting our solar system (Shostak & Villard 2004), the required energy would be reduced greatly. The limits on narrowband radio signals were 180 - 300 Jy Hz at 1 and 8 GHz, respectively, corresponding to a transmitter with an effective isotropic radiated power of 4E15 W (and 7E15 W) at the distance of KIC 8462852. While these powers requirements are high, even modest targeting could - just as for optical signals - lower these numbers substantially.

Gravitational Microlensing Events as a Target for SETI project

Gravitational Microlensing Events as a Target for SETI project

Author:

Rahvar

Abstract:

Detection of signals from a possible extrasolar technological civilization is one of the challenging efforts of science. In this work, we propose using natural telescopes made of single or binary gravitational lensing systems to magnify leakage of electromagnetic signals from a remote planet harbours an Extra Terrestrial Intelligent (ETI) technology. The gravitational microlensing surveys are monitoring a large area of Galactic bulge for searching microlensing events and each year they find more than 2000 events. These lenses are capable of playing the role of natural telescopes and in some occasions they can magnify signals from planets orbiting around the source stars in the gravitational microlensing systems. Assuming that frequency of electromagnetic waves used for telecommunication in ETIs is similar to ours, we propose follow-up observation of microlensing events with radio telescopes such as Square Kilometre Array (SKA), Low Frequency Demonstrators (LFD) and Mileura Wide-Field Array (MWA). Amplifying signals from leakage of broadcasting of Earth-like civilizations will allow us to detect them up to the center of Milky Way galaxy. Our analysis shows that in binary microlensing systems, the probability of amplification of signals from ETIs is more likely than that in the single microlensing events. Finally we propose a practical observational strategy with the follow-up observation of binary microlensing events with the SKA as a new program for searching ETIs. The probability of detection in the optimistic values for the factors of Drake equation is around one event per year.

Detecting Light Sails in Exoplanetary Systems for SETI

SETI via Leakage from Light Sails in Exoplanetary Systems

Authors:

Guillochon et al

Abstract:

The primary challenge of rocket propulsion is the burden of needing to accelerate the spacecraft's own fuel, resulting in only a logarithmic gain in maximum speed as propellant is added to the spacecraft. Light sails offer an attractive alternative in which fuel is not carried by the spacecraft, with acceleration being provided by an external source of light. By artificially illuminating the spacecraft with beamed radiation, speeds are only limited by the area of the sail, heat resistance of its material, and power use of the accelerating apparatus. In this paper, we show that leakage from a light sail propulsion apparatus in operation around a solar system analogue would be detectable. To demonstrate this, we model the launch and arrival of a microwave beam-driven light sail constructed for transit between planets in orbit around a single star, and find an optimal beam frequency on the order of tens of GHz. Leakage from these beams yields transients with flux densities of 0.1 Jy and durations of seconds at 100 pc. Because most travel within a planetary system would be conducted between the habitable worlds within that system, multiply-transiting exoplanetary systems offer the greatest chance of detection, especially when the planets are in projected conjunction as viewed from Earth. If interplanetary travel via beam-driven light sails is commonly employed in our galaxy, this activity could be revealed by radio follow-up of nearby transiting exoplanetary systems. The expected signal properties define a new strategy in the search for extraterrestrial intelligence (SETI).

Watching for the City Lights During the Nights of Exoplanets

Modeling Indications of Technology in Planetary Transit Light Curves -- Dark-side illumination

Authors:

Korpela et al

Abstract:

We analyze potential effects of an extraterrestrial civilization's use of orbiting mirrors to illuminate the dark side of a synchronously rotating planet on planetary transit light curves. Previous efforts to detect civilizations based on side effects of planetary-scale engineering have focused on structures affecting the host star output (e.g. Dyson spheres). However, younger civilizations are likely to be less advanced in their engineering efforts, yet still capable of sending small spacecraft into orbit. Since M dwarfs are the most common type of star in the solar neighborhood, it seems plausible that many of the nearest habitable planets orbit dim, low-mass M stars, and will be in synchronous rotation. Logically, a civilization evolving on such a planet may be inspired to illuminate their planet's dark side by placing a single large mirror at the L2 Lagrangian point, or launching a fleet of small thin mirrors into planetary orbit. We briefly examine the requirements and engineering challenges of such a collection of orbiting mirrors, then explore their impact on transit light curves. We incorporate stellar limb darkening and model a simplistic mirror fleet's effects for transits of Earth-like (R = 0.5 to 2 R_Earth) planets which would be synchronously rotating for orbits within the habitable zone of their host star. Although such an installation is undetectable in Kepler data, JWST will provide the sensitivity necessary to detect a fleet of mirrors orbiting Earth-like habitable planets around nearby stars.

Next Gen SETI

SETI reloaded: Next generation radio telescopes, transients and cognitive computing

Author:

Garrett

Abstract:

The Search for Extra-terrestrial Intelligence (SETI) using radio telescopes is an area of research that is now more than 50 years old. Thus far, both targeted and wide-area surveys have yet to detect artificial signals from intelligent civilisations. In this paper, I argue that the incidence of co-existing intelligent and communicating civilisations is probably small in the Milky Way. While this makes successful SETI searches a very difficult pursuit indeed, the huge impact of even a single detection requires us to continue the search. A substantial increase in the overall performance of radio telescopes (and in particular future wide-field instruments such as the Square Kilometre Array – SKA), provide renewed optimism in the field. Evidence for this is already to be seen in the success of SETI researchers in acquiring observations on some of the world׳s most sensitive radio telescope facilities via open, peer-reviewed processes. The increasing interest in the dynamic radio sky, and our ability to detect new and rapid transient phenomena such as Fast Radio Bursts (FRB) is also greatly encouraging. While the nature of FRBs is not yet fully understood, I argue they are unlikely to be the signature of distant extra-terrestrial civilisations. As astronomers face a data avalanche on all sides, advances made in related areas such as advanced Big Data analytics, and cognitive computing are crucial to enable serendipitous discoveries to be made. In any case, as the era of the SKA fast approaches, the prospects of a SETI detection have never been better.

Keck Fails to Find Evidence of Laser Sources Around 2796 Stars in Optical SETI Search

A Search for Optical Laser Emission Using Keck HIRES

Authors:

Tellis et al

Abstract:

We present a search for laser emission coming from point sources in the vicinity of 2796 stars, including 1368 Kepler Objects of Interest (KOIs) that host one or more exoplanets. We search for extremely narrow emission lines in the wavelength region between 3640 and 7890 Angstroms using the Keck 10-meter telescope and spectroscopy with high resolution (λ/Δλ = 60,000). Laser emission lines coming from non-natural sources are distinguished from natural astrophysical sources by being monochromatic and coming from an unresolved point in space. We search for laser emission located 2-7 arcsec from the 2796 target stars. The detectability of laser emission is limited by Poisson statistics of the photons and scattered light, yielding a detection threshold flux of approximately 10−2 photons m−2s−1 for typical Kepler stars and 1 photon m−2s−1 for solar-type stars within 100 light-years. Diffraction-limited lasers having a 10-meter aperture can be detected from 100 light-years away if their power exceeds 90 W, and from 1000 light-years away (Kepler planets), if their power exceeds 1 kW (from lasers located 60-200 AU, and 2000-7000 AU from the nearby and Kepler stars, respectively). We did not find any such laser emission coming from any of the 2796 target stars. We discuss the implications for the search for extraterrestrial intelligence (SETI).