Natalia Almada, a 37-year-old filmmaker in Mexico City; Raj Chetty, a 33-year-old public economist who teaches at Harvard; and Eric A. Coleman, a 47-year-old physician in Denver, have now become connected, part of an eclectic group whose lives were recently, and irrevocably, changed with a single telephone call.

The three were among the 23 MacArthur Fellows for 2012, whose names were revealed Monday afternoon, ahead of the official announcement scheduled for 12:01 a.m. Tuesday. The fellowships from the John D. and Catherine T. MacArthur Foundation, awards that can’t be applied for, are the stuff of fantasy. Besides the imprimatur of outstanding achievement, they come with a no-strings-attached $100,000 a year for five years.

The 13 men and 10 women named fellows this year range in age from 31 to 66 and, as in years past, are a diverse group. They include an astronomer, a stringed instrument bow maker, two photographers and a marine ecologist. This year the boldface names belong to writers and musicians: Junot Díaz, 43, the writer and professor at the Massachusetts Institute of Technology; Chris Thile, 31, a mandolinist and composer in New York City; David Finkel 56, a Washington Post reporter; Dinaw Mengestu, 34, a novelist and journalist in Washington; and Claire Chase, 34, a flutist and arts entrepreneur in Brooklyn.