The G search for extraterrestrial civilizations with large energy supplies. IV. the signatures and information content of transiting megastructures

Jason T. Wright, Kimberly M.S. Cartier, Ming Zhao, Daniel Jontof-Hutter, Eric B. Ford

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

Arnold, Forgan, and Korpela et al. noted that planet-sized artificial structures could be discovered with Kepler as they transit their host star. We present a general discussion of transiting megastructures, and enumerate 10 potential ways their anomalous silhouettes, orbits, and transmission properties would distinguish them from exoplanets. We also enumerate the natural sources of such signatures. Several anomalous objects, such as KIC 12557548 and CoRoT-29, have variability in depth consistent with Arnold's prediction and/or an asymmetric shape consistent with Forgan's model. Since well-motivated physical models have so far provided natural explanations for these signals, the ETI hypothesis is not warranted for these objects, but they still serve as useful examples of how non-standard transit signatures might be identified and interpreted in a SETI context. Boyajian et al. recently announced KIC 8462852, an object with a bizarre light curve consistent with a "swarm" of megastructures. We suggest that this is an outstanding SETI target. We develop the normalized information content statistic M to quantify the information content in a signal embedded in a discrete series of bounded measurements, such as variable transit depths, and show that it can be used to distinguish among constant sources, interstellar beacons, and naturally stochastic or artificial, information-rich signals. We apply this formalism to KIC 12557548 and a specific form of beacon suggested by Arnold to illustrate its utility.

Original languageEnglish (US)
Article number17
JournalAstrophysical Journal
Volume816
Issue number1
DOIs
StatePublished - Jan 1 2016

Fingerprint

civilization
transit
Project SETI
beacons
signatures
extrasolar planets
light curve
energy
planets
planet
statistics
formalism
orbits
stars
prediction
predictions
energy supply

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

@article{10bdcba1faad44a5839479b4c66ec4fa,
title = "The G search for extraterrestrial civilizations with large energy supplies. IV. the signatures and information content of transiting megastructures",
abstract = "Arnold, Forgan, and Korpela et al. noted that planet-sized artificial structures could be discovered with Kepler as they transit their host star. We present a general discussion of transiting megastructures, and enumerate 10 potential ways their anomalous silhouettes, orbits, and transmission properties would distinguish them from exoplanets. We also enumerate the natural sources of such signatures. Several anomalous objects, such as KIC 12557548 and CoRoT-29, have variability in depth consistent with Arnold's prediction and/or an asymmetric shape consistent with Forgan's model. Since well-motivated physical models have so far provided natural explanations for these signals, the ETI hypothesis is not warranted for these objects, but they still serve as useful examples of how non-standard transit signatures might be identified and interpreted in a SETI context. Boyajian et al. recently announced KIC 8462852, an object with a bizarre light curve consistent with a {"}swarm{"} of megastructures. We suggest that this is an outstanding SETI target. We develop the normalized information content statistic M to quantify the information content in a signal embedded in a discrete series of bounded measurements, such as variable transit depths, and show that it can be used to distinguish among constant sources, interstellar beacons, and naturally stochastic or artificial, information-rich signals. We apply this formalism to KIC 12557548 and a specific form of beacon suggested by Arnold to illustrate its utility.",
author = "Wright, {Jason T.} and Cartier, {Kimberly M.S.} and Ming Zhao and Daniel Jontof-Hutter and Ford, {Eric B.}",
year = "2016",
month = "1",
day = "1",
doi = "10.3847/0004-637X/816/1/17",
language = "English (US)",
volume = "816",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",

}

The G search for extraterrestrial civilizations with large energy supplies. IV. the signatures and information content of transiting megastructures. / Wright, Jason T.; Cartier, Kimberly M.S.; Zhao, Ming; Jontof-Hutter, Daniel; Ford, Eric B.

In: Astrophysical Journal, Vol. 816, No. 1, 17, 01.01.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The G search for extraterrestrial civilizations with large energy supplies. IV. the signatures and information content of transiting megastructures

AU - Wright, Jason T.

AU - Cartier, Kimberly M.S.

AU - Zhao, Ming

AU - Jontof-Hutter, Daniel

AU - Ford, Eric B.

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Arnold, Forgan, and Korpela et al. noted that planet-sized artificial structures could be discovered with Kepler as they transit their host star. We present a general discussion of transiting megastructures, and enumerate 10 potential ways their anomalous silhouettes, orbits, and transmission properties would distinguish them from exoplanets. We also enumerate the natural sources of such signatures. Several anomalous objects, such as KIC 12557548 and CoRoT-29, have variability in depth consistent with Arnold's prediction and/or an asymmetric shape consistent with Forgan's model. Since well-motivated physical models have so far provided natural explanations for these signals, the ETI hypothesis is not warranted for these objects, but they still serve as useful examples of how non-standard transit signatures might be identified and interpreted in a SETI context. Boyajian et al. recently announced KIC 8462852, an object with a bizarre light curve consistent with a "swarm" of megastructures. We suggest that this is an outstanding SETI target. We develop the normalized information content statistic M to quantify the information content in a signal embedded in a discrete series of bounded measurements, such as variable transit depths, and show that it can be used to distinguish among constant sources, interstellar beacons, and naturally stochastic or artificial, information-rich signals. We apply this formalism to KIC 12557548 and a specific form of beacon suggested by Arnold to illustrate its utility.

AB - Arnold, Forgan, and Korpela et al. noted that planet-sized artificial structures could be discovered with Kepler as they transit their host star. We present a general discussion of transiting megastructures, and enumerate 10 potential ways their anomalous silhouettes, orbits, and transmission properties would distinguish them from exoplanets. We also enumerate the natural sources of such signatures. Several anomalous objects, such as KIC 12557548 and CoRoT-29, have variability in depth consistent with Arnold's prediction and/or an asymmetric shape consistent with Forgan's model. Since well-motivated physical models have so far provided natural explanations for these signals, the ETI hypothesis is not warranted for these objects, but they still serve as useful examples of how non-standard transit signatures might be identified and interpreted in a SETI context. Boyajian et al. recently announced KIC 8462852, an object with a bizarre light curve consistent with a "swarm" of megastructures. We suggest that this is an outstanding SETI target. We develop the normalized information content statistic M to quantify the information content in a signal embedded in a discrete series of bounded measurements, such as variable transit depths, and show that it can be used to distinguish among constant sources, interstellar beacons, and naturally stochastic or artificial, information-rich signals. We apply this formalism to KIC 12557548 and a specific form of beacon suggested by Arnold to illustrate its utility.

UR - http://www.scopus.com/inward/record.url?scp=84952897408&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84952897408&partnerID=8YFLogxK

U2 - 10.3847/0004-637X/816/1/17

DO - 10.3847/0004-637X/816/1/17

M3 - Article

AN - SCOPUS:84952897408

VL - 816

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 17

ER -