Giant ‘X’ at the Center of the Milky Way Confirmed Via Twitter
An X-shaped cluster of stars was identified by Twitter users in an open-access photo of the Milky Way galaxy.
Dustin Lang, research associate for the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto who specializes in the analysis of astronomical images, posted on Twitter photos of the galaxy taken from NASA's Wide-field Infrared Survey Explorer (WISE).
"Scientists on Twitter often share sneak peeks of interesting results or pretty pictures," Lang told CNN.
But his followers noticed something unusual about the Milky Way - an X-shaped bulge at the heart of the galaxy.
I don't want to admit how long it took to summarize 150 gigapixels into this WISE W1/W2 image. pic.twitter.com/za8x07XKIE
— Dustin Lang (@dstndstn) May 7, 2015
The discovery on the NASA photo prompted the scientists to do a study about this X-shaped star cluster. Earlier studies had already pointed out the existence of the X-shaped bulge in the Milky Way. But thanks to Lang's photos and Twitter followers, the X-shaped bulge was finally viewed clearly in photos for the first time.
"The bulge is a key signature of formation of the Milky Way," Melissa Ness, co-author of the news study and researcher at the Max Planck Institute of Astronomy in Germany, said in a press release. She and Lang had authored the new study about the X-shaped stars and published their insights in The Astronomical Journal.
"If we understand the bulge we will understand the key processes that have formed and shaped our galaxy," Ness added.
WISE had taken two infrared surveys of the sky in 2010, which allowed for better visibility of galaxies and their structures because infrared light can see through the visible light issue of dust, CNN reports.
According to the scientists, the Milky Way galaxy is a barred spiral galaxy: a disk-shaped collection of dust, gas and billions of stars, 100,000 light-years in diameter. Unlike a simple disk structure, the galaxy is composed of two spiral arms, a bar-shaped feature that runs through its center, and a central bulge of stars.
The "bar" resembles a rectangular box or peanut when viewed from within the plane of the galaxy. If the bar buckles, the stars will then move in a perpendicular motion, creating an X-shape of stars.
Using the infrared data, the scientists were able to have the clearest view of the X-shaped bulge and discovered that the structure is full of crossing stars.
"This shape implies that the bulge has therefore formed in large part via dynamical instabilities from the disk," Ness told CNN. "This basically tells us how the galaxy has formed."
The researchers are continuing their study on the Milky Way and the movement of stars within the bulge in hopes of knowing Earth's home galaxy more.