Perhaps NASA should hire a detective. Their own private eye, the Hubble Space Telescope, has done a decent job of sleuthing out a mysterious object in the constellation Centaurus but astronomers are still having a hard time figuring out exactly what it is.

Dynamic Duo

Click the image above to watch a simulation of He2-90's red giant feeding its companion star with gaseous material.

The object, known as He2-90, is currently classified as a planetary nebula, an expanding shell of stellar gases surrounding a dying star. But new Hubble observations suggest that the object may actually be much older than previously thought and in fact not one, but two objects coyly disguised as one.

"This object in no way looks like any planetary nebula that weve ever seen," said Raghvendra Sahai, an astronomer with NASAs Jet Propulsion Laboratory in Pasadena, California. "We now think He2-90 is a binary star a pair of stars orbiting each other."

The two stars are thought to be a pair of elderly stars -- a red giant, or bloated aging star, and a white dwarf, a small degenerate star thats nearing end of its life. And according to Sahai, the red giant appears to be shedding its outer layers into a disk of material feeding into the white dwarf.

Astronomers say that since such an accretion disk would need gravity to form, the two stars likely orbit relatively close to one another about 10 astronomical units, or ten times the distance from Earth to the sun. Such close proximity, they say, would help explain the two magnificent gas jets that can be seen streaming from the center of He2-90.

Observations show that the two gas jets appear to be spewing particles at around 621 miles (1,000 kilometers) per second. Whats more, at only 30 years old, they are amazingly young. The jets can be seen in Hubbles latest image as the horizontal striped streaks emanating from He2-90s central bright area (the other four light rays are artifacts of Hubbles optics system).

Because they predict He2-90s gas jets are moving so fast, astronomers think they may soon know a lot more about the properties of the jets. "If we take another image, we can compare the images and measure the speed," said Sahai. "Well also be using another instrument to measure the movement of the gas."

Unfortunately, He2-90s stars are not directly visible to the cameras on board the Hubble Space Telescope because they are obscured by dust. But astronomers are hoping to learn more about the area with the help of another space telescope: the Chandra X-ray Observatory.

According to Sahai, astronomers have uncovered a curious source of high-energy gamma-ray radiation near He2-90. If Chandra, which measures and records such high-energy rays, can confirm the source is coming from He2-90 itself, then the stellar duo now suspected to reside in He2-90 may again be something completely different from what astronomers now think they are.

"That would be quite a surprise," said Sahai. "Instead of a white dwarf being the companion star in this binary system, it would probably be something like a neutron star or a black hole."