The Alpha Centauri party in May 2028

"Were you planning to stay around until 2028?"

"I'd be 77. Why, something worth waiting for?"

"The star Alpha Centauri A, you know, the one which is 4 light years from Earth and maybe has planets, will be coming in front of a distant red giant star. It will act as a microlens, flaring the red giant into an Einstein ring."

"Sounds pretty. What's the red star?

"It's called 2MASS 14392160-6049528 but they seem to have named it S5 for short. It's roughly 10,000 light years away."

"And the possible Centauri planets?"

"Microlensing again. Planetary effects will be discernable as fluctuations in the extended image of the red giant."

An enlargement of the conjunction that will occurs in 2028, with the Einstein ring
caused by Alpha Cen A represented in cyan color. Credit: Pierre Kervella.

There are currently no reported planets around Alpha Centauri A. There is a suspected planet in tight orbit around its close binary partner, Alpha Centauri B.

Meanwhile there is better evidence of a planet around the more distant (from A/B) Alpha Centauri C, better known as Proxima - the nearest extrasolar star to Earth.

The Proxima planet, "lies in the habitable zone of Proxima Centauri, but it is possible that the planet is tidally locked to the star," It's a possible target for the super-laser-powered  Breakthrough Starshot initiative to send interstellar nanocraft to Alpha Centauri within the next fifty years.

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Something no-one discussed. If we wanted (for some reason) to communicate with the red giant star S5, the Centauri microlensing event would be the perfect way to do it via communications amplification through gravitational lensing.

The only problem is that we'd need to fire up the lasers in 2019 - and they won't be ready.

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Hat tip Centauri Dreams.