J/AJ/152/181 SETI observations of exoplanets with the ATA (Harp+, 2016)
SETI observations of exoplanets with the Allen Telescope Array.
Harp G.R., Richards J., Tarter J.C., Dreher J., Jordan J., Shostak S.,
Smolek K., Kilsdonk T., Wilcox B.R., Wimberly M.K.R., Ross J., Barott W.C.,
Ackermann R.F., Blair S.
<Astron. J., 152, 181-181 (2016)>
=2016AJ....152..181H 2016AJ....152..181H (SIMBAD/NED BibCode)
ADC_Keywords: Planets ; Stars, double and multiple ; Stars, nearby ;
Interferometry
Keywords: astrobiology - extraterrestrial intelligence -
instrumentation: interferometers - planetary systems -
planets and satellites: terrestrial planets -
radio lines: planetary systems
Abstract:
We report radio SETI observations on a large number of known
exoplanets and other nearby star systems using the Allen Telescope
Array (ATA). Observations were made over about 19000hr from 2009 May
to 2015 December. This search focused on narrowband radio signals from
a set totaling 9293 stars, including 2015 exoplanet stars and Kepler
objects of interest and an additional 65 whose planets may be close to
their habitable zones. The ATA observations were made using multiple
synthesized beams and an anticoincidence filter to help identify
terrestrial radio interference. Stars were observed over frequencies
from 1 to 9GHz in multiple bands that avoid strong terrestrial
communication frequencies. Data were processed in near-real time for
narrowband (0.7-100Hz) continuous and pulsed signals with
transmitter/receiver relative accelerations from -0.3 to 0.3m/s2. A
total of 1.9x108 unique signals requiring immediate follow-up were
detected in observations covering more than 8x106 star-MHz. We
detected no persistent signals from extraterrestrial technology
exceeding our frequency-dependent sensitivity threshold of
180-310x10-26W/m2.
Description:
We report radio Search for ExtraTerrestrial Intelligence (SETI)
observations on a large number of known exoplanets and other nearby
star systems using the Allen Telescope Array (ATA). The ATA is an LNSD
array (Large Number, Small Diameter, or Large Number of Small Dishes)
consisting of 42 dishes with 6.1m diameter placed within an area
approximately 300 by 150m on the ground. A 6.1m dish has a half-power
beam width of 3.5° divided by the observing frequency in GHz. This
is the maximum possible field of view of the array. Observations were
made over about 19000hr from 2009 May to 2015 December, completing a
total of 210000 separate observations in 20-40MHz blocks on 9293 stars
covering a total of 7.3 million star MHz at selected frequencies
between 1 and 9GHz. The set of 9293 stars includes 2015 exoplanet
stars and Kepler objects of interest and an additional 65 whose
planets may be close to their habitable zones.
Table6 lists the various targets that at one time or another were
listed in the habitable zone catalog, along with the percentage of the
1-9GHz available bandwidth over which each was measured. All the other
observation targets in this campaign is found in Table7.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 33 65 *List of all targets having exoplanets near their
habitable zone
table7.dat 46 9224 List of all targets where at least a 100MHz
bandwidth was observed, not including habitable
zone targets of table6
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Note on table6.dat: The table does not show the percentages of the 1-9GHz
bandwidth and the frequencies of observation because they are all 100% and
9000MHz, respectively.
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See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 5 F5.2 h RAhour Right Ascension in decimal hours (J2000)
6- 11 F6.2 deg DEdeg Declination in decimal degrees (J2000)
13- 33 A21 --- Name Target name(s)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1 A1 --- S [HKT] Sample code (K=Kepler star, H=HabCat star,
or T=Tycho Backup star)
3- 7 F5.2 h RAhour Right Ascension in decimal hours (J2000)
9- 14 F6.2 deg DEdeg Declination in decimal degrees (J2000)
16- 37 A22 --- Name Target name
39- 41 I3 % Percent [1/100] Completeness (percentage of 1-9GHz range
that was searched)
43- 46 I4 MHz BW [100/9000] Total searched frequency bandwidth
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 08-Mar-2017