An object obscured by dust, and buried in a two-star system enshrouded by dense gas, is not easy to find.
A "cloaked" star was discovered after it ate a little of its neighbor. The meal must have given the star a bit of indigestion,
because it "burped" with a blast of high-energy radiation, which gave it away.
Three satellites involved in a search, finally uncovered a unique and elusive neutron star but it was not any easy task.
At first, scientists could not immediately decipher the nature of the object so they combined their efforts by using ESA's
Integral satellite, tracking extreme radiation across the Universe and two NASA satellites, Swift and Rossi X-ray Timing Explorer.
"We are always hunting for new sources," said Simona Soldi, the scientist at the Integral Science Data Centre in Geneva, Switzerland, who first saw the neutron star.
"It is exciting to find something so elusive. How many more sources like this are out there?"
Artist's impression of neutron star IGR J16283-4838 orbiting its companion star.
Matter flowing from the companion to the neutron star, attracted by strong gravity, occasionally flares up in X-ray and gamma-ray light.
Such flares last only for a few days or weeks but reveal the location of an otherwise dim system. Credits: NASA/Dana Berry
Neutron stars are the core remains of 'supernovae', exploded stars once about ten times as massive as our Sun. They contain about a
Sun's worth of mass compacted into a sphere about 20 kilometres across.
This artist's impression illustrates neutron star IGR J16283-4838 flaring. This is due to the matter accreted from its companion star. Credits: NASA/Dana Berry
IGR J16283-4838 is located deep in a double hiding place, inside the spiral arm Norma of our Milky Way galaxy, approximately 20,000 light years away.
Click on image to enlarge
Credits: Chandra X-ray Center, Operated for NASA by the Smithsonian Astrophysical Observatory
According to Dr. Volker Beckmann of NASA Goddard Space Flight Center in Greenbelt, Md., lead author on a paper regarding the subject,
the Milky Way's spiral arms are full of black holes, neutron stars, and many other exotic objects.
Despite this diversity of objects, there is a problem with observing them because the spiral arms of the Milky Way are too dusty
to see through. The only way to get data about hidden objects is to combine the mutual work of X-ray and gamma-ray telescopes.
IGR J16283-4838 is the seventh so-called 'highly absorbed', or hidden neutron star to be identified. Neutron stars, created from fast-burning massive stars, are intrinsically tied to star formation rates. They are also energetic 'beacons' in regions too dusty to study in detail otherwise.
IGR J16283-4838 revealed itself with an 'outburst' on or near its surface. Neutron stars such as IGR J16283-4838 are often part
of binary systems, orbiting a normal star. Occasionally, gas from the normal star, lured by gravity, crashes onto the surface of
the neutron star and releases a great amount of energy. These outbursts can last for weeks before the system returns to dormancy for months or years.
Integral, the Rossi Explorer and Swift all detect X-rays and gamma rays, which are far more energetic than the visible light that our eyes detect.
Yet each satellite has different capabilities.
Swift contains a high-resolution X-ray telescope, which allowed scientists to zoom in on IGR J16283-4838.
The Rossi Explorer has a timing spectrometer, a device used to uncover properties of the light source, such as speed and
rapid variations in the order of milliseconds.
Integral has a large field of view, enabling it to scan our Milky Way galaxy for neutron stars and black hole activity.
Radio Emission From Ultracool Dwarf Detected By Arecibo Telescope
The Arecibo Telescope in Puerto Rico has discovered sporadic bursts of polarized radio emission from the T6.5 brown J1047+21.
Because Arecibo is a single, fixed-dish telescope, it has a restricted practical sensitivity to weak, quiescent emission from radio sources...
Invader From Another Galaxy
This alien intruder from another galaxy is in many ways different from other exoplanets observed by astronomers.
Located about 2000 light-years from Earth in the southern constellation of Fornax (the Furnace), the Jupiter-like planet orbits a dying star of
extragalactic origin and risks to be engulfed by it.
Power To See Most Distant Objects In The Universe
The 3C294, is one of the most distant galaxies recorded by Chandra, the most sophisticated X-ray observatory ever built.
The cluster 3C294 is even 40 percent farther (!) than the next most distant x-ray galaxy cluster.
Chandra focus on X-rays from high-energy regions of the Universe and see the invisible.
It is so sensitive that it can capture images of particles as they disappear into a black hole deep in outer space.