New Planets Revealed Thanks to IR Cameras & Multi-Spectral Cameras

A new technique has uncovered a hidden extra solar planet in images taken 11 years ago in by The Hubble Space Telescope. This technique introduced our new friend, an exoplanet.
The technique was used to find an exoplanet that went undetected in Hubble images taken in latter 1998 with its Near Infrared Imaging Camera (NIR) and Multi-Object Spectrometer (NICMOS).
Astronomers discovered the planet's existence from images via the Keck and Gemini North telescopes from 2007 and then 2008. By then, Hubble had taken its first pictures of the particular system.
Previously, (NICMOS) could not see the other two planets because its coronagraphic spot. This is a device that blots out the glare of a star. This device also blocked its view of the two most inner planets.
The planet in question is estimated to be seven times the mass of Jupiter or larger. It is the outermost of three colossal planets known to orbit the juvenile star HR 8799, which is 130 light-years or 130AU away from Earth.
“NICMOS is more powerful than previously thought for imaging planets," said David Lafreniere of the University of Toronto in Canada. David is the scientist who discovered the heavenly body "Our new image-processing technique efficiently subtracts the glare from a star that spills over the coronagraph's edge, allowing us to see planets that are one-tenth the brightness of what could be detected before with Hubble."
Imaging the exoplanet is not an easy task. Planets can be billions of times fainter than the star around in which they orbit and they are typically located at separations smaller than 1/2,000th the viewed size of the full moon, as seen from Earth, a very short distance from their star.
The planet recovered in the NICMOS data is roughly 100,000 times fainter than the star when viewed in the near-infrared spectrum.
In the past twenty years, scientists have spotted more than 300 extrasolar planets circling other stars in the Milky Way galaxy.
Lafreniere adapted an image reconstruction technique that was first developed for ground-based observatories. Lafreniere recovered the planet in NICMOS data taken 10 years before the Keck/Gemini discovery using this new technique.
"To get a good determination of the orbit we have to wait a very long time because the planet is moving so slowly the planet has a 400-year cycle. The 10-year-old Hubble data take us that much closer to having a precise measure of the orbit."
NICMOS's view provided new insights into the physical characteristics of the planet, too. This was possible because NICMOS works at near-infrared wavelengths that are severely blocked by Earth's atmosphere due to absorption by water vapor.
With the success of this planet hunt, scientists hope they can find more extrasolar planets hiding in the plethora of images Hubble has taken in its lifetime.
"During the past 10 years Hubble has been used to look at over 200 stars with coronagraphy, looking for planets and disks. We plan to go back and look at all of those archived images and see if anything can be detected that has gone undetected until now," said Christian Marois of the Herzberg Institute of Astrophysics, Victoria, Canada.
If researchers see something once but its brightness and separation from the star would be reasonable for a planet, researchers will also do follow-up observations with ground-based telescopes.

Keith Dartez