Hiding Inside a Dark Cosmic Cloud
Cambridge, Ma (United States):
In an exercise that demonstrates the power of a multiwavelength investigation using diverse facilities, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have deciphered the true nature of a mysterious object hiding inside a dark cosmic cloud. They found that the cloud, once thought to be featureless, contains a baby star, or possibly a failed star known as a "brown dwarf," that is still forming within its dusty cocoon.
Observations indicate that the mystery object has a mass about 25 times that of Jupiter, which would place it squarely in the realm of brown dwarfs. However, its mass may eventually grow large enough to qualify it as a small star. The object also is cool and faint, shining with less than 1/20 the sun's luminosity.
"This object is the runt of the star formation family," said CfA astronomer Tyler Bourke.
Establishing the true nature of the object required the unique capabilities of the Submillimeter Array (SMA) in Hawaii. "The SMA spotted what no single-dish telescope could see," said Bourke.
Using the SMA, scientists detected a weak outflow of material predicted by star formation theories. That outflow-10 times smaller in mass than any seen before-confirmed both the low-mass nature of the object and its association with the surrounding dark cloud. "The sensitivity and resolution of the Submillimeter Array with its multiple antennas were crucial in detecting the outflow," said Bourke.
The puzzling object was discovered using a Smithsonian-developed infrared camera on board NASA's Spitzer Space Telescope. Spitzer studied the dusty cosmic cloud named L1014 as part of the Cores to Disks Legacy program. A core is the densest region of a cloud, massive enough to make a star like the sun.
L1014, located about 600 light-years away in the constellation Cygnus the Swan, initially was classified as a "starless core" because it showed no evidence for star formation. Astronomers were surprised when Spitzer images revealed a faint infrared light source that appeared to be within the core.
Additional data were needed to confirm that the faint object was directly associated with the dark core, rather than being a chance superposition of a more distant, more mundane background object.
Near-infrared observations by the MMT Observatory in Arizona revealed a scattered light nebula surrounding the faint central object in L1014. "Light from the object is bouncing off surrounding dust and toward us," said CfA astronomer Tracy Huard, who took the MMT images. "Reflection nebulosity like that is a fingerprint of an embedded object."
Oct 04, 2005
PhysOrg.com, VA
Cambridge, Ma (United States):In an exercise that demonstrates the power of a multiwavelength investigation using diverse facilities, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have deciphered the true nature of a mysterious object hiding inside a dark cosmic cloud. They found that the cloud, once thought to be featureless, contains a baby star, or possibly a failed star known as a "brown dwarf," that is still forming within its dusty cocoon.
Observations indicate that the mystery object has a mass about 25 times that of Jupiter, which would place it squarely in the realm of brown dwarfs. However, its mass may eventually grow large enough to qualify it as a small star. The object also is cool and faint, shining with less than 1/20 the sun's luminosity.
"This object is the runt of the star formation family," said CfA astronomer Tyler Bourke.
Establishing the true nature of the object required the unique capabilities of the Submillimeter Array (SMA) in Hawaii. "The SMA spotted what no single-dish telescope could see," said Bourke.
Using the SMA, scientists detected a weak outflow of material predicted by star formation theories. That outflow-10 times smaller in mass than any seen before-confirmed both the low-mass nature of the object and its association with the surrounding dark cloud. "The sensitivity and resolution of the Submillimeter Array with its multiple antennas were crucial in detecting the outflow," said Bourke.
The puzzling object was discovered using a Smithsonian-developed infrared camera on board NASA's Spitzer Space Telescope. Spitzer studied the dusty cosmic cloud named L1014 as part of the Cores to Disks Legacy program. A core is the densest region of a cloud, massive enough to make a star like the sun.
L1014, located about 600 light-years away in the constellation Cygnus the Swan, initially was classified as a "starless core" because it showed no evidence for star formation. Astronomers were surprised when Spitzer images revealed a faint infrared light source that appeared to be within the core.
Additional data were needed to confirm that the faint object was directly associated with the dark core, rather than being a chance superposition of a more distant, more mundane background object.
Near-infrared observations by the MMT Observatory in Arizona revealed a scattered light nebula surrounding the faint central object in L1014. "Light from the object is bouncing off surrounding dust and toward us," said CfA astronomer Tracy Huard, who took the MMT images. "Reflection nebulosity like that is a fingerprint of an embedded object."
Oct 04, 2005
PhysOrg.com, VA
