Astronomers using data from the Atacama Large Millimeter/submillimeter Array (ALMA) have found a distant object in the direction of Alpha Centauri. The object appears to be in the outer region of our solar system, and depending on its distance could be a hypothesized ”super-Earth.”
ALMA is capable of precise observations at short microwave wavelengths, typically emitted by cold gas and dust. But objects on the edge of our solar system also emit light in this range, and would be too cool and distant to be observed by infrared telescopes. In 2014, ALMA found a faint object in the direction of Alpha Centauri A & B. The object was again observed in May of this year, this time more clearly. Given that the object is within a few arcseconds of the Alpha Centauri system, it would seem reasonable to presume that it could be part of that system, possibly gravitationally bound as Alpha Centauri D. The Centauri system is about 4 light years away, and at that distance (given the object’s brightness at submillimeter wavelengths) it would have to be a red dwarf star. But such a star would also be clearly visible in the infrared, so if this object is Alpha Centauri D we should have seen it long ago.
Since it doesn’t seem to be part of the Alpha Centauri system, it must be closer and correspondingly smaller. With just two observations it isn’t possible to determine the object’s orbit, so we can only guess at its distance and size.
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Astronomers Find New Object, Possible Super-Earth In Our Solar System
