May 28, 1998
Photo No: H98-19a
Hubble's First Direct Look at Possible Planet Around Another Star
This NASA Hubble Telescope near-infrared image of newborn binary stars
(image center) reveals a long thin nebula pointing toward a faint
companion object (bottom left) which could be the first extrasolar
planet to be imaged directly.
The brightest objects in the image are the binary protostars, which
illuminate an extended cloud of gas and dust (image center) from which
the stars formed. So much dust surrounds these protostars that they
are virtually invisible at optical wavelengths. However, near-infrared
light penetrates the overlying dust, revealing the newborn stars
within. The faint multicolor cross extending from the neighborhood of
the binary is an artifact produced when HST observes bright stars.
At lower left there is a point of light many times fainter than the
binary. Theoretical calculations indicate that this companion is much
too dim to be an ordinary star; instead, a hot young protoplanet
several times the mass of Jupiter is consistent with the observed
brightness. The candidate protoplanet appears at a distance of 130
billion miles from the binary (1400 times the Earth's distance from
the Sun). A bright streak of nebulosity extends from the binary
toward the faint companion, possibly indicating that the protoplanet
was ejected from the binary system.
Current models predict that very young giant planets are still warm
from gravitational contraction and formation processes, with
temperatures as high as a few thousand degrees Fahrenheit. This makes
them relatively bright in infrared light compared to old giant planets
such as Jupiter. Even so, young planets are difficult to find in new
solar systems because the glare of the central star drowns out their
feeble glow. Young planets ejected from binary systems would therefore
represent a unique opportunity to study extrasolar planets with
current astronomical technology.
The image was taken on August 4, 1997 with the Near Infrared Camera
and Multi-Object Spectrometer (NICMOS).
Credit: Susan Terebey (Extrasolar Research Corp.), and NASA