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SETI astronomers find no evidence for artificial transmitters at Oumuamua | Astronomy

In October 2017, a rapidly moving object of extra-solitary origin, the name "Oumuamua", was discovered near the ground with a…

In October 2017, a rapidly moving object of extra-solitary origin, the name “Oumuamua”, was discovered near the ground with a ground-based telescope on Hawai. Motivated by the hypothesis that “Oumuamua could be an interstellar probe, astronomers used to use the SETI Institute Allen Telescope Array (ATA) to search for radio transmissions that would indicate a non-natural origin for the object.

This artist’s impression shows the first interstellar asteroid – 1I / 2017 U1 (“Oumuamua”). Kornmesser / ESO.

After its discovery in October 2017, “Oumuamua was the subject of popular speculation about a possible non-natural origin.

The very elongated form and the fact that no coma was observed

A recently published newspaper by Harvard Smithsonian Center for Astrophysics Researcher Dr Shmuel Bialy and Professor Abraham Loeb has also suggested the possibility that “Oumuamua is a deliberate construction.” [Oumuamuaärenavsiktligkonstruktion19659005] The scientists argued that the small unexpected acceleration observed for this object could be caused by pressure from the sunlight as “Oumumua swung around the sun. Their hypothesis is that the object can be a light sail, either deliberately or accidentally sent.

A deliberate origin is considered to be more likely because our solar system is a very small target for any object that is not directed towards. 19659005] Such arguments reinforce the importance of observations that can limit the true nature of “Oumuamua.”

Plot of Point Source matches the “Oumuamua Position with 100 KHz Interval from 1-10 GHz. Image Credits: Harp et al doi: 10.1016 / j.actaastro.2018.10 .046.

“We were looking for a signal that would show that this item contains some technology – that it was of artificial origin,” says SETI Institute Researcher, Dr. Gerry Harp, author of a paper published online in the journal Acta Astronautica .

“We found no such emissions, despite a rather sensitive search. While our observations do not conclusively rule out a non-natural origin for “Oumuamua”, they constitute important tasks for assessing their likely makeup. “

Dr. Harp and co-author observed” Oumuamua when it was about 170 million miles away, or slightly less than the diameter of the earth’s path. “

The observations were made between November 23 and December 5, 2017 using the ATA broadband correlator frequencies between 1 and 10 GHz and at a frequency resolution of 100 kHz.

No signals were found at a level that would be produced by an omnidirectional transmitter on board the object with an output of about 10 watts or more

In parts of the radio spectrum routinely moved with artificial satellite metrics, the threshold for detection was higher.

In any event, these limits for the powers that can be detected are quite modest – comparable to a citizenship radio.


] GR Harpa et al . 2019. Radio SETI observations of the interstellar object “Oumuamua.” Acta Astronautica 155: 51-54; doi: 10,1016 / j.actaastro.2018.10.046

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