Gliese Andrea Catalán
It is
called Gliese 581d and orbits the star of the same name (without the last
letter), a red dwarf star located 20 light years from Earth, along with five
other worlds, some also very interesting. The extrasolar planet was discovered
in 2009 by researchers at Queen Mary College London and Hertfordshire, who
presented it as the first super-Earth found in habitable zone, ie, a world of a
size somewhat larger than ours which is the right distance from their star to
support liquid water on its surface, an indispensable condition for the
existence of life as we know it.
The
candidate planet was discovered using a spectrometer that measures the
"wobble" small changes in the wavelength of the light emitted by a
star caused by a planet orbiting around it. However, a report published last
year in Science magazine rejected the existence of this planet, considering
what astronomers saw was nothing more than "stellar activity disguised as
a planet." In his view, the world was actually supposed noise in the data
caused by star spots.
The
"fathers" of the "d" are not achantado, insist that their
planet exists and ensure that the findings of his colleagues have been caused
by inadequate analysis of the data. The statistical technique used in the
investigation of 2014 to account for stellar activity is, as explained,
"just enough" to identify smaller planets as Gliese 581d.
In his
view, that approach has worked in the past in identifying the larger planets
because its effect on the star was too important to deny the errors in the
results. However, it makes it almost impossible to find smaller planets signals
within the noise caused by the stellar variability itself.
"It
has always been there"
Using a
more accurate model on existing data, researchers are convinced that the signal
GJ 581d is real, despite the stellar variability. "The existence (or not)
of GJ 581d is significant because it was the first similar to Earth discovered
in the" Goldilocks "planet (the habitable zone, not too hot, not too
cold, as in the fairy tale) about another star (where water can exist in liquid
form) and is a reference case for the Doppler technique, "explains Guillem
Anglada-Escudé, lead author of the article.
"There
are always discussions among scientists about the way we interpret the data,
but I'm sure 581d has been in orbit around Gliese 581 all the time," added
the researcher. "In any case, the strength of his statement was too
strong. If his treatment of the data is correct, then some projects search for
planets in Earth-based observatories have to be revised significantly as they
are intended to detect even smaller planets. You have to be more careful with
these claims, "he warns.
The star
Gliese 581 is a source of findings for planet hunters, but also a source of
controversy. In 2010, astronomers at the University of California Santa Cruz
and the Carnegie Institution of Washington announced the discovery of the first
planet "really living" outside our solar system, the planet 'g',
another of the six known worlds of the system. As has happened with his brother
'd', the 'g' was also questioned just a few weeks after being announced
officialy, but also in the same way, the discovery team turned to bring new
evidence that seemed to confirm their existence. Certainly not fail to
give Gliese surprises
No comments:
Post a Comment