Star-grazing: Majewski's got the Milky Way's menu
"Cannibalistic Milky Way found devouring entrails of smaller Sagittarius kin!" A headline from the Weekly World News?
Think again– it's actually a summary of recent research by University of Virginia astronomer Steve Majewski, who, along with UVA's Mike Skrutskie and University of Massachusetts' Martin Weinberg, recently announced the Milky Way is no milquetoast.
The 42-year-old Chicago native's interest in space ignited at age eight when his father drove the family to see the Apollo 11 launch. After triple majoring in math, physics, and integrated science at Northwestern University, Majewski entered the University of Chicago, working feverishly to complete his dissertation on galactic structure, when he first became suspicious of the Milky Way's appetite. With a job waiting in Pasadena, California, he was anxious to finish his Ph.D.
"My advisor came in and said, 'You shouldn't panic unless you discover something really weird, like an outer layer spinning backwards,'" he recalls, laughing, "and that's exactly what happened."
The Milky Way, Majewski explains, is like a whirling pinwheel, whose center moves faster than the outer edge. To his shock, he discovered the Milky Way's outermost stars weren't just moving slower; they were actually going in reverse.
Why? Majewski proposed a radical theory: The wayward stars were actually the glittering guts of smaller galaxies recently consumed by the Milky Way, whose former orbits had not yet been digested.
Most astronomers were skeptical. "People were very nice to my face," Majewski remembers, "but, behind my back, they thought I'd screwed up."
"He was the leader in the church of assimilation," says colleague Mike Skrutskie, "that our galaxy is made up of smaller galaxies."
Convinced he was right, Majewski, who joined UVA in 1995, continued to preach the gospel of the Milky Way's cannibalism. And this past year, he finally had his proof. Using cutting-edge infrared maps, Majewski and Skrutskie realized they could witness the Sagittarius galaxy's "dance of death," as the Milky Way's gravitational pull ripped its stars into ragged strings.
"This is what I had been looking for for 15 years," Majewski says, adding, "I've given up a lot of my normal life for this because it's a once-in-a-lifetime discovery." His team's astronomical account of Sagittarius' demise will appear in December's Astrophysical Journal.
But, astrology fans, fear not! Majewski points out, "Astronomers have this annoying habit of naming any new galaxy after the constellation it's behind." Sagittarius, the constellation, is safe.
When not studying our galaxy's gluttony, Majewski plays the didgeridoo. He explains he randomly picked up the instrument in Pasadena, only to learn later, according to Aboriginal myth, termites blown out of the first didjeridu scattered across the sky to form the Milky Way.
PHOTO BY JEN FARIELLO