SETI & Technosignatures

234 Sun-like Stars Have Some Curious Spectral Lines and Signals

By Keith Cowing
Press Release
astro-ph.SR
October 24, 2016
Filed under
234 Sun-like Stars Have Some Curious Spectral Lines and Signals

A Fourier transform analysis of 2.5 million spectra in the Sloan Digital Sky Survey was carried out to detect periodic spectral modulations. Signals having the same period were found in only 234 stars overwhelmingly in the F2 to K1 spectral range.

The signals cannot be caused by instrumental or data analysis effects because they are present in only a very small fraction of stars within a narrow spectral range and because signal to noise ratio considerations predict that the signal should mostly be detected in the brightest objects, while this is not the case. We consider several possibilities, such as rotational transitions in molecules, rapid pulsations, Fourier transform of spectral lines and signals generated by Extraterrestrial Intelligence (ETI).

They cannot be generated by molecules or rapid pulsations. It is highly unlikely that they come from the Fourier transform of spectral lines because too many strong lines located at nearly periodic frequencies are needed. Finally we consider the possibility, predicted in a previous published paper, that the signals are caused by light pulses generated by Extraterrestrial Intelligence to makes us aware of their existence.

We find that the detected signals have exactly the shape of an ETI signal predicted in the previous publication and are therefore in agreement with this hypothesis. The fact that they are only found in a very small fraction of stars within a narrow spectral range centered near the spectral type of the sun is also in agreement with the ETI hypothesis. However, at this stage, this hypothesis needs to be confirmed with further work. Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars.

Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars

E.F. Borra, E. Trottier
(Submitted on 10 Oct 2016)

Comments: Accepted for publication by PASP: Signals probably from Extraterrestrial Intelligence. Analysis of 2.5 million SDSS spectra found signals predicted in a previous publication in only 234 stars overwhelmingly in the F2 to K1 spectral range
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
DOI: 10.1088/1538-3873/128/969/114201
Cite as: arXiv:1610.03031 [astro-ph.SR] (or arXiv:1610.03031v1 [astro-ph.SR] for this version)
Submission history
From: Ermanno F. Borra [view email]
[v1] Mon, 10 Oct 2016 19:10:47 GMT (2258kb)
https://arxiv.org/abs/1610.03031

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