by It is our galaxy’s strangest star, a flickering ball of light whose erratic and unpredictable output has baffled astronomers for decades. But now the study of Boyajian’s star is being promoted as a research model that could help one of the most interesting scientific quests: finding intelligent life on other worlds.
This is the argument that the astrophysicist from the University of Oxford, Professor Chris Lintott, will give at a public lecture – Is it Aliens? The Most Unusual Star in the Galaxy – at a Gresham College lecture in Conway Hall, central London on Monday. Its main target will be Boyajian’s star, sometimes called Tabby’s star after the scientist Tabetha Boyajian, in the Cygnus constellation whose dimming and surprising brightness has been the subject of intense study by space probes and observatories in recent years.
“It is unusual behaviour,” Lintott told the Observer. “There are quick, random bursts where its brightness drops dramatically and then returns. There is no pattern to it. It flickers as if someone is playing with their dimmer switch. There is no other star like this in our galaxy.”
Boyajian’s star was studied in detail by the Kepler space observatory in 2012 when its erratic behavior was first discovered. These observations indicated that the star’s massive mass of matter curls into a tight formation and occasionally blocks its light.
But what is the nature of this vast mass of matter? Dust rings, disintegrating comets and asteroid blades have been put forward as explanations. However, the most attention was given to the theory, proposed by scientists at Penn State University, that the eclipsing mass could be a huge alien megastructure.
Humanity may get on the radio in about 50 years – and that is likely to be true of civilizations on other worlds.
Chris Lintott, astrophysicist
Such constructions were proposed by the physicist Freeman Dyson, who argued that many alien civilizations might be advanced enough to build massive arrays of solar panels around their home stars to capture their heat and light . The astronomers used Dyson spheres or so-called swarms, and the large orbital elements would be used to power the distant civilizations.
The idea that astronomers had stumbled upon such a structure sparked headlines across the globe – though not for long. Subsequent research has now undermined the idea. “We’ve found that different wavelengths of light are blocked to different extents: exactly what you’d expect from starlight passing through a dust cloud,” Lintott said.
Boyajian’s eclipsing mass is likely a dust cloud produced when a planet grazed too close to its surface and was torn apart. However, the study of the strange object is important because it highlights techniques that are destined to become more important as efforts to find alien civilizations increase in the coming years, according to Lintott.
As a result, humanity could become radio-quiet in about 50 years – and that is likely to be true of civilizations on other worlds“The search for extraterrestrial intelligence [Seti] changing,” he said. “In the past we relied almost entirely on radio telescopes to detect broadcasts from alien civilizations just as our radio and television transmissions could reveal our presence to them. However, so far, we have heard nothing.”
We shouldn’t be surprised either, argues Lintott. “Humanity has already passed the peak output of radio waves because we are increasingly using narrow beam communications and fiber optic cables, rather than sending television and radio signals out into the general environment.”
As a result, humanity may become on the radio in about 50 years – and that is likely to be true of civilizations on other worlds, he said. “They will go radio silent after a while, like us. So the Seti radio telescope needs to be augmented with other ways to look for aliens. We will have to be more creative in what we look for in the data and find unusual things that would indicate that they are the work of aliens.”
The search for Dyson fields – giant panels of solar arrays – will be one key way, although other ways of finding the work of aliens will also be needed. An example would be provided by an alien civilization mining asteroids near their home planet, an effort that would create interplanetary dust clouds that would expose themselves to their infrared radiation.
“And while aliens cannot reveal themselves through radio transmission, they could easily detect their presence from their radar emissions that they use to guide their aircraft and spacecraft,” Lintott said. “Again, we need to look at these wavelengths for signs that they are there.”
Such work will require analyzes of vast repositories of data and Boyajian’s star story also provides an important indication of how they would be done. Its secrets were revealed by an army of citizen scientists, members of the public who collected and analyzed the vast reams of data from the instruments that probed the star, Lintott said.
“It was their joint analysis of Boyajian’s data that showed it was behaving in a very strange way – and it is very likely that they will be linked to other strange stars in our galaxy in future projects.” And you never know, the next time they could hit pay dirt.”
