A mysterious infant star that behaves like a strobe light has been spotted by NASA's two great telescopes - the Spitzer and Hubble.
Every 25.34 days, the object, designated LRLL 54361, unleashes a burst of light.
Although a similar phenomenon has been observed in two other young stellar objects, this is the most powerful such
beacon seen to date.
The heart of the fireworks is hidden behind a dense disk and envelope of dust. Astronomers propose the light flashes
are caused by periodic interactions between two newly formed stars that are binary, or gravitationally bound to each
Click on image to enlarge
NASA's Spitzer and Hubble space telescopes have teamed up to uncover a mysterious infant star that behaves like a police strobe light.
Left: This is a false-color, infrared-light Spitzer image of LRLL 54361 inside the star-forming region IC 348 located
950 light-years away and has an unusual variable object that has the typical signature of a protostar.
Center: This Hubble Space Telescope monochromatic-color image resolves the detailed structure around the protostar, consisting of two cavities that are traced by light scattered off their edges above and below a dusty disk.
Right: This is an artist's impression of the hypothesized central object that may be two young binary stars.
Image credit: NASA, ESA, J. Muzerolle (STScI), E. Furlan (NOAO and Caltech), K. Flaherty (Univ. of Ariz./Steward Observatory), Z.
Balog (Max Planck Institute for Astronomy), and R. Gutermuth (Univ. Mass. Amherst)
Astronomers, who used NASA's Hubble Space Telescope to confirm the Spitzer observations and reveal the detailed stellar
structure around LRLL 54361, theorize the flashes are caused by material suddenly being dumped onto the growing stars, known as protostars.
A blast of radiation is unleashed each time the stars get close to each other in their orbits. This phenomenon, called
pulsed accretion, has been seen in later stages of star birth, but never in such a young system or with such intensity
"This protostar has such large brightness variations with a precise period that it is very difficult to explain,"
said James Muzerolle of the Space Telescope Science Institute in Baltimore, Md. His paper recently was published
in the science journal Nature.
This video, created from a sequence of images from the Hubble Space Telescope, shows a pulse of light emanating from the protostellar object LRLL 54361. Most if not all of this light results from scattering off circumstellar dust in the protostellar envelope. An apparent edge-on disk, visible at the center of the object and three separate structures are interpreted as outflow cavities.
The extent and shape of the scattered light changes substantially over a 25.34-day period. This is caused by the propagation of the light pulse through the nebula. Astronomers propose that the flashes are due to material in a circumstellar disk suddenly being dumped onto the growing stars and unleashing a blast of radiation each time the stars get close to each other in their orbit.
Credit: NASA, ESA, and J. Muzerolle, Z. Levay, and G. Bacon (STScI)
LRLL 54361 represents the early stages of star formation when lots of gas and dust is being rapidly accreted,
or pulled together, to form a new binary star.
It's a variable object inside the star-forming region IC 348, located 950 light-years from Earth. Data from Spitzer
revealed the presence of protostars. Based on statistical analysis, the two stars are estimated to be no more than a
few hundred thousand years old.
The Spitzer infrared data, collected repeatedly during a period of seven years, showed unusual outbursts in the
brightness of the suspected binary protostar. Surprisingly, the outbursts recurred every 25.34 days, which is a
very rare phenomenon.