Download Two Studies Directly Image Planets Around Foreign Stars

Two Studies Directly Image Planets Around Foreign Stars
Two studies, using different methods, directly imaged exoplanets around two different
stars, a "first" for astronomy. The reports always emphasize how noteworthy this
accomplishment is and positively review the news. The articles also caution that the
planets have to be verified and that there is doubt among some that planets were
actually observed. However, even with this, the reporting is optimistic about the
techniques bringing more results in the future.
NBC Nightly News (11/13, story 11, 1:55, Williams, 9.87M) reported, "We don't get to
announce news like this that often. In the world of astronomy, some new pictures
released today are being hailed as nothing short of the beginning of a new era. ... Until
today, they hadn't actually seen one beyond our solar system. Our report from our chief
science correspondent Robert Bazell." NBC (Bazell) added: "They are our first glimpse
of planets outside our solar system. They orbit nearby stars. At the American Museum
of Natural History, astronomer Ben Oppenheimer says it opens a whole new field of
study." Bazell: "The KEK and Gemini telescopes in Hawaii reveal the system of at least
three planets around a star called HR-87899, that we see in the night sky in the
constellation Pegasus. The Hubble space telescope saw a planet three times the size of
Jupiter orbiting a bright star called Fumblholdt. In the past astronomers inferred the
existence of planets by measuring the movement of stars. But this is the first time they
have actually seen a distant planet.
USA Today (11/14, Vergano, 2.28M) reports, "Astronomers reported Thursday that they
have the first snapshot of another solar system - one with three planets larger than
Jupiter - orbiting a nearby star." The planets around HR 8799 were pictured by a
Canadian-US team led by Christian Marois of the National Research Council Canada.
"Marois and colleagues essentially collected infrared light from the star over time, and
then subtracted light emanating directly from the star, to leave behind an image of the
three orbiting planets." The planets are "cloud-topped giants, says Marois. They
resemble Jupiter and Saturn but are much heavier at 7 to 10 times the mass of Jupiter,"
but other scientists "caution that more observations by independent groups will be
required to confirm that the images are true snapshots of nearby planets."
The New York Times (11/14, A1, Overbye, 1.12M), in a front page story, reports, "The
achievement, the result of years of effort on improved observational techniques and
better data analysis, presages more such discoveries, the experts said." Another group
"led by Paul Kalas...found a planet orbiting the star Fomalhaut, only 25 light-years from
Earth." Kalas' planet, which also was visibly seen, is about three times the size of
Jupiter. All of the planets orbit much farther from their star than the Earth from the sun.
"Marois and his colleagues used the 8-meter in diameter Gemini North and the 10meter Keck telescopes on Mauna Kea in Hawaii" and "Kalas did his work with the
Hubble Space Telescope."
The Washington Post (11/14, A1, Achenbach, 696K), on its front page, reports, "Seeing
an extrasolar planet directly was one of the last and most speculative goals of the
Hubble Space Telescope when it was put in orbit in 1990, said Edward J. Weiler,
associate administrator of NASA's science mission directorate." Both systems' stars
"are much younger and hotter than our sun. Any planets around them would be unlikely
to harbor life." Author and astronomer Alan Boss "said he's not ready to accept that the
new objects are truly planets" as the models that estimated the planets' mass "have not
been precisely calibrated. And Fomalhaut b has its own ambiguities. It is not clear
whether the light is coming from a planet or from a disk of dust surrounding a planet."
The Los Angeles Times (11/14, Johnson, 833K) reports, "The two teams used different
techniques to solve the problem. Berkeley's Kalas relied on Hubble's Advanced Camera
for Surveys," as he noticed "the inner edge of the ring was sharply defined, raising his
suspicions that there was something hiding in there that had a lot of gravity." The
Fomalhaut planet "represents the lowest mass planet yet found outside our solar
system, [Eugene Chiang of UC Berkeley] said, bringing the day closer when
researchers might be able to find Earth-like planets." According to the article, "These
twin discoveries mean researchers have now found alien planets whose orbits are close
to (the wobble technique) and far away (direct imaging studies) from stars outside our
solar system. That still leaves a vast area in between."
The Christian Science Monitor (11/14, Spotts, 56K) reports, "Two broad factors now
make these observations possible, researchers say. One involves technology." Larger
telescopes and more sensitive detectors make "astronomers...better able to spot
planets. They do this with hardware as well as software that in effect dims the star." The
second is a better selection of potential targets, according to the article. "By focusing on
young solar systems, planets are still gathering material and contracting. So they give
off heat. All this makes it easier for increasingly sensitive infrared detectors. ... The holy
grail, of course, is to find Earth-like planets at Earth-like distances from sun-like stars.
That is likely to await a new generation of space-based telescope."
The AP (11/14, Borenstein) reports, "There are disputes about whether these are the
first exoplanet photos. Others have made earlier claims, but those pictures haven't been
confirmed as planets or universally accepted yet. The photos released Thursday are
being published in a scientifically prominent journal, but that still hasn't convinced all the
experts."
Bloomberg News (11/14, Dolmetsch) reports, "The discovery may prove to be the
'Rosetta Stone" that allows astronomers to find similar planets in other dust rings
around stars, said Marc Kuchner, an exoplanet scientist with NASA's Goddard Space
Flight Center."
New Scientist (11/14, Courtland) reports, "The newly discovered planets - which all lie at
least four times that distance from their host stars - could challenge the leading model of
how planets form, says [Ray] Jayawardhana" of the University of Toronto, who was not
part of either study. "Far from a star, matter in the disc thins out and takes longer to
orbit. This might mean that distant, nascent planets do not have enough time to form a
core before a star's radiation blasts away the surrounding gas."
Physics World (11/13) reports, "Although all four of the new exoplanets are thought to
be well below the threshold of 13 times the mass of Jupiter, which is when a planet
technically becomes a brown dwarf, the estimates rely on models of planetary evolution
that are subject to sizeable uncertainties."
The Baltimore Sun (11/14, Roylance, 249K), Contra Costa (CA) Times (11/14, Bohan),
AFP (11/14), CNN (11/14, Ansari), Space.com (11/14, Bryner), Scientific American
(11/14, Matson), Nature News (11/14, Yeager), Science NOW (11/14, Kerr), BBC News
(11/14), Sky and Telescope (11/13, Naeye), Wired's (11/13, Moskowitz) "Wirred
Science" blog, Canadian Press (11/14), UPI (11/14), Canwest (11/14, Spears), the UK's
Daily Telegraph (11/14, Gray), and the Baltimore Examiner's (11/13, Philips) "Space
News Examiner" blog also cover the story.
Same Class Of Stars May Have Icy Planets. Science News (11/14, Cowen) reports in
an upcoming report of a survey of young A-type stars, "the same class of massive star
that includes Fomalhaut and HR 8799," by the Spitzer Telescope "show that the dusty
disks swaddling these stars have the right temperature to have formed from the collision
of icy planetary bodies about as small as Pluto. The finding suggests that about half of
all A stars have have tiny, icy planets."
Cosmos Magazine (11/14, Cathpole) reports, "The researchers used data from NASA's
Spitzer Space Telescope and the ROSAT All-Sky Survey...to observe A- and B-type
stars that dwell 25 million light-years away in the constellation Monoceros." The
research revealed cold dusty disks around 12 of the stars and warmer disks around only
one. By comparing the temperature of the disks to planetary formation models, they
calculated that the colder disks were formed by "the debris of icy planet-forming
collisions" and "predicted that young stars, around 25 million years old, and slightly
more massive than the Sun, would likely have dozens of 1000-kilometre-sized nascent
planets." Chris Tinney from the University of New South Wales doubts the results and
said, "They've demonstrated A-type stars have these 24 micrometre emissions – that
doesn't necessarily mean they produce icy planets. Many things in space have cold
dust, it doesn't necessarily mean that icy planets."
Astronomers Gets Direct Images Of Two Extra-solar Planetary Systems.
Astronomers using the Hubble Space Telescope to image the star Fomalhaut believe
they have captured the first extra-solar planet ever detected directly in visible light. A
separate near-infrared image collected with the Keck and Gemini telescopes in Hawaii
directly revealed what are believed to be three more planets in the extra-solar system
surrounding the star HR8799, 140 light years distant. If the scientists are correct -- and
there is some expert skepticism -- the two images would be the first created with
radiation reaching Earth directly from planets circling other stars. More than 300 other
extra-solar planets have been detected, but only through indirect measurements of the
effect they have on their stars' motion through the heavens. In the case of the planet
known as Fomalhaut b, scientists used the coronagraph on the Hubble's Advanced
Camera for Survey (ACS) in 2004 to create a false eclipse blocking the star itself -- one
of the brightest objects in the sky and easily visible to the unaided eye in the southern
constellation Piscis Australis.The result was an image of a dust ring circling the star with
the planet visible just inside the ring, which scientists believe is comparable to the
Kuiper Belt beyond Neptune. A second image collected in 2006 showed how far the
planet had moved in its 872-Earth-year orbit. The planet itself is 10.7 billion miles from
the star, which is 27 light years from Earth. The ACS has since failed, and astronauts
plan to repair it when they return for the final Hubble servicing mission next year. If they
succeed, astronomers want to use it to collect additional direct images of Fomalhaut b,
and to collect infrared images of the planet's glow with the Hubble's Near Infrared
Camera and Multi-Object Spectrometer as well.- Frank Morring, Jr. *
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