Interesting question. If it did come from Vega's area 600,000 years ago, the author argues that the civilization sent out billions of these devices to every star using solar sail technology. Kind of like if we sent out billions of Voyager 1s deliberately to every star for them to be discovered upon arrival.

They have our understanding of physics but seemingly way more ability to mass produce and launch these items into interstellar space in specific ways for stars to collide with them.

Or it's a 2 billion year old sandblasted rock that caught some weird gravity assists :)