46 research outputs found
A 1.1 to 1.9 GHz SETI Survey of the Kepler Field: I. A Search for Narrow-band Emission from Select Targets
We present a targeted search for narrow-band (< 5 Hz) drifting sinusoidal
radio emission from 86 stars in the Kepler field hosting confirmed or candidate
exoplanets. Radio emission less than 5 Hz in spectral extent is currently known
to only arise from artificial sources. The stars searched were chosen based on
the properties of their putative exoplanets, including stars hosting candidates
with 380 K > T_eq > 230 K, stars with 5 or more detected candidates or stars
with a super-Earth (R_p 50 day orbit. Baseband voltage data
across the entire band between 1.1 and 1.9 GHz were recorded at the Robert C.
Byrd Green Bank Telescope between Feb--Apr 2011 and subsequently searched
offline. No signals of extraterrestrial origin were found. We estimate that
fewer than ~1% of transiting exoplanet systems host technological civilizations
that are radio loud in narrow-band emission between 1-2 GHz at an equivalent
isotropically radiated power (EIRP) of ~1.5 x 10^21 erg s^-1, approximately
eight times the peak EIRP of the Arecibo Planetary Radar, and we limit the the
number of 1-2 GHz narrow-band-radio-loud Kardashev type II civilizations in the
Milky Way to be < 10^-6 M_solar^-1. Here we describe our observations, data
reduction procedures and results.Comment: Accepted to the Astrophysical Journa
Status of the UC-Berkeley SETI Efforts
We summarize radio and optical SETI programs based at the University of
California, Berkeley. The SEVENDIP optical pulse search looks for ns time scale
pulses at visible wavelengths using an automated 30 inch telescope. The ongoing
SERENDIP V.v sky survey searches for radio signals at the 300 meter Arecibo
Observatory. The currently installed configuration supports 128 million
channels over a 200 MHz bandwidth with ~1.6 Hz spectral resolution. SETI@home
uses the desktop computers of volunteers to analyze over 160 TB of data at
taken at Arecibo looking for two types of continuous wave signals and two types
of pulsed signals. A version to be released this summer adds autocorrelation
analysis to look for complex wave forms that have been repeated (and overlayed)
after a short delay. SETI@home will soon be processing data of Kepler exoplanet
systems collected at the GBT. The Astropulse project is the first SETI search
for s time scale dispersed pulses in the radio spectrum. We recently
reobserved 114 sky locations where microsecond pulses were detected. This data
is in process of being transferred to Berkeley for analysis.Comment: 8 pages, including 1 figure. Presented at SPIE Conf. 8152, San Diego,
CA, Aug 25, 201
On Detecting Interstellar Scintillation in Narrowband Radio SETI
To date, the search for radio technosignatures has focused on sky location as
a primary discriminant between technosignature candidates and anthropogenic
radio frequency interference (RFI). In this work, we investigate the
possibility of searching for technosignatures by identifying the presence and
nature of intensity scintillations arising from the turbulent, ionized plasma
of the interstellar medium (ISM). Past works have detailed how interstellar
scattering can both enhance and diminish the detectability of narrowband radio
signals. We use the NE2001 Galactic free electron density model to estimate
scintillation timescales to which narrowband signal searches would be
sensitive, and discuss ways in which we might practically detect strong
intensity scintillations in detected signals. We further analyze the RFI
environment of the Robert C. Byrd Green Bank Telescope (GBT) with the proposed
methodology and comment on the feasibility of using scintillation as a filter
for technosignature candidates.Comment: 17 pages, 8 figures, published by Ap
Panoramic optical and near-infrared SETI instrument: prototype design and testing
The Pulsed All-sky Near-infrared Optical Search for ExtraTerrestrial
Intelligence (PANOSETI) is an instrument program that aims to search for fast
transient signals (nano-second to seconds) of artificial or astrophysical
origin. The PANOSETI instrument objective is to sample the entire observable
sky during all observable time at optical and near-infrared wavelengths over
300 - 1650 nm. The PANOSETI instrument is designed with a number of modular
telescope units using Fresnel lenses (0.5m) arranged on two geodesic
domes in order to maximize sky coverage. We present the prototype design
and tests of these modular Fresnel telescope units. This consists of the design
of mechanical components such as the lens mounting and module frame. One of the
most important goals of the modules is to maintain the characteristics of the
Fresnel lens under a variety of operating conditions. We discuss how we account
for a range of operating temperatures, humidity, and module orientations in our
design in order to minimize undesirable changes to our focal length or angular
resolution.Comment: 12 pages, 8 figures, 1 tabl
Current and Nascent SETI Instruments
Here we describe our ongoing efforts to develop high-performance and
sensitive instrumentation for use in the search for extra-terrestrial
intelligence (SETI). These efforts include our recently deployed Search for
Extraterrestrial Emissions from Nearby Developed Intelligent Populations
Spectrometer (SERENDIP V.v) and two instruments currently under development;
the Heterogeneous Radio SETI Spectrometer (HRSS) for SETI observations in the
radio spectrum and the Optical SETI Fast Photometer (OSFP) for SETI
observations in the optical band. We will discuss the basic SERENDIP V.v
instrument design and initial analysis methodology, along with instrument
architectures and observation strategies for OSFP and HRSS. In addition, we
will demonstrate how these instruments may be built using low-cost, modular
components and programmed and operated by students using common languages, e.g.
ANSI C.Comment: 12 pages, 5 figures, Original version appears as Chapter 2 in "The
Proceedings of SETI Sessions at the 2010 Astrobiology Science Conference:
Communication with Extraterrestrial Intelligence (CETI)," Douglas A. Vakoch,
Edito