January 10th 05, 08:00 PM
HUBBLE'S INFRARED EYES HOME IN ON SUSPECTED EXTRASOLAR PLANET
>From Hubble Space Telescope Science Institute and UA News Services
January 10, 2005
Unique follow up observations carried out with NASA's Hubble Space
Telescope
are providing important supporting evidence for the existence of a
candidate
planetary companion to a relatively bright young brown dwarf star
located
225 light-years away in the southern constellation Hydra.
Astronomers at the European Southern Observatory's Very Large Telescope
(VLT) in Chile detected the planet candidate in April 2004 with
infrared
observations using adaptive optics to sharpen their view. The VLT
astronomers spotted a faint companion object to the brown dwarf star
2MASSWJ
1207334-393254 (aka 2M1207). The object is a candidate planet because
it is
only one-hundredth the brightness of the brown dwarf (at the
longer-than-Hubble wavelengths observed with the VLT) and glimmers at
barely
1800 degrees Fahrenheit, which is cooler than a light bulb filament.
Because an extrasolar planet has never been directly imaged before,
this
remarkable observation required Hubble's unique abilities to do
follow-up
observations to test and validate if it is indeed a planet. Hubble's
Near
Infrared Camera and Multi-Object Spectrometer (NICMOS) camera conducted
complementary observations taken at shorter infrared wavelength
observations
unobtainable from the ground. This wavelength coverage is important
because
it is needed to characterize the object's physical nature.
Very high precision measurements of the relative position between the
dwarf
and companion were obtained with NICMOS in August 2004. The Hubble
images
were compared to the earlier VLT observations to try and see if the two
objects are really gravitationally bound and hence move across the sky
together. Despite the four months between the VLT and NICMOS
observations,
astronomers say they can almost rule out the probability that the
suspected
planet is really a background object, because there was no noticeable
change
in its position relative to the dwarf.
If the two objects are indeed gravitationally bound together they are
at
least 5 billion miles apart, about 30 percent farther apart than Pluto
is
from the Sun. Given the mass of 2M1207, inferred from its spectrum, the
companion object would take a sluggish 2,500 years to complete one
orbit.
Therefore, any relative motion seen between the two on much shorter
time
scales would reveal the candidate planet to be a background interloper
and
not a gravitationally bound planet.
"The NICMOS photometry supports the conjecture that the planet
candidate is
about five times the mass of Jupiter if it indeed orbits the brown
dwarf,"
says Glenn Schneider of the University of Arizona. "The NICMOS position
measurements, relative to VLT's, indicate the object is a true (and
thus
orbiting) companion at a 99 percent level of confidence - but further
planned Hubble observations are required to eliminate the 1 percent
chance
that it is a coincidental background object which is not orbiting the
dwarf."
----------------------------------------------------------------
Science Contact Information
Glenn Schneider 520.621.5865
Media Contact Information
Dolores Beasley, NASA 202.358.1753
Ray Villard, HST Science Institute, 410.338.4514
Lori Stiles, UA 520.626.4402
Related Web site
http://hubblesite.org/newscenter/newsdesk/archive/releases/2005/03/
------------------------------------------------------------------
Schneider is presenting these latest Hubble observations today at the
meeting of the American Astronomical Society in San Diego, Calif.
The candidate planet and dwarf are in the nearby TW Hydrae association
of
young stars that are estimated to be no older than 8 million years. The
Hubble NICMOS observations found the object to be extremely red and
relatively much brighter at longer wavelengths. The colors match
theoretical
expectations for an approximately 8 million-year-old object that is
about
five times as massive as Jupiter.
Further Hubble observations by the NICMOS team are planned in April
2005.
Electronic image files and additional information are available at the
http://hubblesite.org/news/2005/03 and
http://nicmosis.as.arizona.edu:8000/AAS_JAN_2005/PR_11_14.html Websites.
>From Hubble Space Telescope Science Institute and UA News Services
January 10, 2005
Unique follow up observations carried out with NASA's Hubble Space
Telescope
are providing important supporting evidence for the existence of a
candidate
planetary companion to a relatively bright young brown dwarf star
located
225 light-years away in the southern constellation Hydra.
Astronomers at the European Southern Observatory's Very Large Telescope
(VLT) in Chile detected the planet candidate in April 2004 with
infrared
observations using adaptive optics to sharpen their view. The VLT
astronomers spotted a faint companion object to the brown dwarf star
2MASSWJ
1207334-393254 (aka 2M1207). The object is a candidate planet because
it is
only one-hundredth the brightness of the brown dwarf (at the
longer-than-Hubble wavelengths observed with the VLT) and glimmers at
barely
1800 degrees Fahrenheit, which is cooler than a light bulb filament.
Because an extrasolar planet has never been directly imaged before,
this
remarkable observation required Hubble's unique abilities to do
follow-up
observations to test and validate if it is indeed a planet. Hubble's
Near
Infrared Camera and Multi-Object Spectrometer (NICMOS) camera conducted
complementary observations taken at shorter infrared wavelength
observations
unobtainable from the ground. This wavelength coverage is important
because
it is needed to characterize the object's physical nature.
Very high precision measurements of the relative position between the
dwarf
and companion were obtained with NICMOS in August 2004. The Hubble
images
were compared to the earlier VLT observations to try and see if the two
objects are really gravitationally bound and hence move across the sky
together. Despite the four months between the VLT and NICMOS
observations,
astronomers say they can almost rule out the probability that the
suspected
planet is really a background object, because there was no noticeable
change
in its position relative to the dwarf.
If the two objects are indeed gravitationally bound together they are
at
least 5 billion miles apart, about 30 percent farther apart than Pluto
is
from the Sun. Given the mass of 2M1207, inferred from its spectrum, the
companion object would take a sluggish 2,500 years to complete one
orbit.
Therefore, any relative motion seen between the two on much shorter
time
scales would reveal the candidate planet to be a background interloper
and
not a gravitationally bound planet.
"The NICMOS photometry supports the conjecture that the planet
candidate is
about five times the mass of Jupiter if it indeed orbits the brown
dwarf,"
says Glenn Schneider of the University of Arizona. "The NICMOS position
measurements, relative to VLT's, indicate the object is a true (and
thus
orbiting) companion at a 99 percent level of confidence - but further
planned Hubble observations are required to eliminate the 1 percent
chance
that it is a coincidental background object which is not orbiting the
dwarf."
----------------------------------------------------------------
Science Contact Information
Glenn Schneider 520.621.5865
Media Contact Information
Dolores Beasley, NASA 202.358.1753
Ray Villard, HST Science Institute, 410.338.4514
Lori Stiles, UA 520.626.4402
Related Web site
http://hubblesite.org/newscenter/newsdesk/archive/releases/2005/03/
------------------------------------------------------------------
Schneider is presenting these latest Hubble observations today at the
meeting of the American Astronomical Society in San Diego, Calif.
The candidate planet and dwarf are in the nearby TW Hydrae association
of
young stars that are estimated to be no older than 8 million years. The
Hubble NICMOS observations found the object to be extremely red and
relatively much brighter at longer wavelengths. The colors match
theoretical
expectations for an approximately 8 million-year-old object that is
about
five times as massive as Jupiter.
Further Hubble observations by the NICMOS team are planned in April
2005.
Electronic image files and additional information are available at the
http://hubblesite.org/news/2005/03 and
http://nicmosis.as.arizona.edu:8000/AAS_JAN_2005/PR_11_14.html Websites.