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Title: OPTICAL SETI OBSERVATIONS OF THE ANOMALOUS STAR KIC 8462852

Abstract

To explore the hypothesis that KIC 8462852's aperiodic dimming is caused by artificial megastructures in orbit, rather than a natural cause such as cometary fragments in a highly elliptical orbit, 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 recommended preparatory exercise for the possible future detection of a candidate signal, three of six observing runs simultaneously searched radio frequencies at the Allen Telescope Array in California. No periodic optical signals greater than 67 photons m{sup −2} within a time frame of 25 ns were seen. If, for example, any inhabitants of KIC 8462852 were targeting our solar system with 5 MJ laser pulses, locally illuminating an approximately 3 au diameter disk, the signal could have been detected at the Boquete Observatory. The limits on narrowband radio signals were 180–300 Jy Hz at 1 and 8 GHz, respectively. While the power requirement for a detectable, isotropic narrowband radio transmission from KIC 8462852 is quite high, even modest targeting on the part of the putative extraterrestrials can lower this power substantially.

Authors:
;  [1]; ;  [2]
  1. METI International, 100 Pine Street, Suite 1250, San Francisco, CA 94111-5235 (United States)
  2. Center for SETI Research, SETI Institute, 189 Bernardo Avenue, Mountain View, CA 94043 (United States)
Publication Date:
OSTI Identifier:
22654485
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 825; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; APPROXIMATIONS; DETECTION; EXERCISE; GHZ RANGE; HYPOTHESIS; LASER RADIATION; ORBITS; PERIODICITY; PHOTOMETERS; PHOTONS; PULSES; RADIOWAVE RADIATION; SOLAR SYSTEM; STARS; TELESCOPES; TRANSMISSION

Citation Formats

Schuetz, Marlin, Vakoch, Douglas A., Shostak, Seth, and Richards, Jon, E-mail: dvakoch@meti.org. OPTICAL SETI OBSERVATIONS OF THE ANOMALOUS STAR KIC 8462852. United States: N. p., 2016. Web. doi:10.3847/2041-8205/825/1/L5.
Schuetz, Marlin, Vakoch, Douglas A., Shostak, Seth, & Richards, Jon, E-mail: dvakoch@meti.org. OPTICAL SETI OBSERVATIONS OF THE ANOMALOUS STAR KIC 8462852. United States. doi:10.3847/2041-8205/825/1/L5.
Schuetz, Marlin, Vakoch, Douglas A., Shostak, Seth, and Richards, Jon, E-mail: dvakoch@meti.org. 2016. "OPTICAL SETI OBSERVATIONS OF THE ANOMALOUS STAR KIC 8462852". United States. doi:10.3847/2041-8205/825/1/L5.
@article{osti_22654485,
title = {OPTICAL SETI OBSERVATIONS OF THE ANOMALOUS STAR KIC 8462852},
author = {Schuetz, Marlin and Vakoch, Douglas A. and Shostak, Seth and Richards, Jon, E-mail: dvakoch@meti.org},
abstractNote = {To explore the hypothesis that KIC 8462852's aperiodic dimming is caused by artificial megastructures in orbit, rather than a natural cause such as cometary fragments in a highly elliptical orbit, 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 recommended preparatory exercise for the possible future detection of a candidate signal, three of six observing runs simultaneously searched radio frequencies at the Allen Telescope Array in California. No periodic optical signals greater than 67 photons m{sup −2} within a time frame of 25 ns were seen. If, for example, any inhabitants of KIC 8462852 were targeting our solar system with 5 MJ laser pulses, locally illuminating an approximately 3 au diameter disk, the signal could have been detected at the Boquete Observatory. The limits on narrowband radio signals were 180–300 Jy Hz at 1 and 8 GHz, respectively. While the power requirement for a detectable, isotropic narrowband radio transmission from KIC 8462852 is quite high, even modest targeting on the part of the putative extraterrestrials can lower this power substantially.},
doi = {10.3847/2041-8205/825/1/L5},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 825,
place = {United States},
year = 2016,
month = 7
}
  • We have utilized the NASA/IRTF 3 m SpeX instrument’s high-resolution spectral mode to observe and characterize the near-infrared flux emanating from the unusual Kepler light curve system KIC 8462852. By comparing the resulting 0.8–4.2 μm spectrum to a mesh of model photospheric spectra, the 6 emission line analyses of the Rayner et al. catalog, and the 25 system collections of debris disks we have observed to date using SpeX under the Near InfraRed Debris disk Survey, we have been able to additionally characterize the system. Within the errors of our measurements, this star looks like a normal solar abundance main-sequencemore » F1V to F3V dwarf star without any obvious traces of significant circumstellar dust or gas. Using Connelley and Greene’s emission measures, we also see no evidence of significant ongoing accretion onto the star nor any stellar outflow away from it. Our results are inconsistent with large amounts of static close-in obscuring material or the unusual behavior of a YSO system, but are consistent with the favored episodic giant comet models of a Gyr old stellar system favored by Boyajian et al. We speculate that KIC 8462852, like the ∼1.4 Gyr old F2V system η Corvi, is undergoing a late heavy bombardment, but is only in its very early stages.« less