Located 7,500 light years from Earth, the binary star system known as Eta Carinae has been puzzling astronomers since its bright eruption in the 1840s.
Now, a supercomputer, space telescopes, and a 3-D printer are providing insight into this mysterious system, in which two massive stars orbiting each other are blowing themselves apart. Because Eta Carinae is surrounded by a dusty nebula, it is difficult to observe. Astronomers have used space telescopes such as the NASA Swift satellite over the past 18 years to measure X-ray emissions by the stars when they come close to each other.
Most recently, a team of researchers used the Pleiades supercomputer at NASA Ames Research Center to simulate the stars’ closest approach.
The computer model showed a spiraling pattern occurring as a result of their close approach. This data was then sent to a 3D printer, which produced a detailed model more specific than anything even space telescopes could observe.
The unstable system is made up of one star approximately 30 times the mass of our Sun and a second, bigger star about 90 times the mass of the Sun. The two orbit one another every 5.5 years.
At closest approach, the lower-mass star slingshots around its companion, with each star spawning stellar winds between one and six million miles per hour (1.6 and 9.6 million km per hour). These winds produce high energy X-rays as they hit each other and heat up surrounding gas.
In August 2014, Eta Carinae generated the brightest X-rays ever recorded.
Bright orange in color, the 3-D printout shows spine-shaped lumps protruding from the spiral that resulted from the stars’ close approach to one another.
NASA Goddard Space Flight Center astrophysicist Thomas Madura acknowledged such features have never been seen prior to now.
“We think these are real physical features that arise due to physical instabilities,” he said.
Results of the study were presented this week at the winter meeting of the American Astronomical Society.
Eta Carinae is the most massive and most luminous object relatively close to Earth and is highly erratic, explained NASA Goddard Space Flight Center astronomer Michael Corcoran. Because it is unstable, the binary system could explode any time as a supernova. The researchers admit that as of now, they have no idea when this or when another eruption like that of the 1840s will happen.
The smaller of the pair was discovered only in 1996.
The 1840s eruption made Eta Carinae the brightest object in the southern sky for a few years and likely resulted in the system ejecting as much as ten solar masses. If it blew up as a supernova, Eta Carinae would appear as bright as the full Moon and be visible during daylight hours.