Posted on 05/01/2015 9:10:45 AM PDT by Red Badger
The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form.
"We have found a small star, with a giant planet the size of Jupiter, orbiting very closely," said researcher George Zhou from the Research School of Astrophysics and Astronomy.
"It must have formed further out and migrated in, but our theories can't explain how this happened."
In the past two decades more than 1,800 extrasolar planets (or exoplanets) have been discovered outside our solar system orbiting around other stars.
The host star of the latest exoplanet, HATS-6, is classed as an M-dwarf, which is one of the most numerous types of stars in galaxy. Although they are common, M-dwarf stars are not well understood. Because they are cool they are also dim, making them difficult to study.
HATS-6 emits only one twentieth of the light of our sun. The giveaway that the faint star had a planet circling it was a dip in its brightness caused as the planet passed in front of the star, observed by small robotic telescopes including telescopes at the ANU Siding Spring Observatory.
To confirm the signal was a planet and not a blip in the system, Dr Bayliss called in help from one of the world's largest telescopes, the Magellan Telescope in Chile, and an amateur astronomer, T G Tan, who operates from his backyard in Perth.
"T G Tan has been really helpful on our projects. He was able to catch the transit of the planet from Perth, after it had set over our horizon," Mr Zhou said.
Subsequent observations from the Chilean telescope, and spectra taken from the ANU 2.3 metre telescope at Siding Spring, confirmed the planet had an orbit of just one-tenth that of mercury, and orbits its star every 3.3 days.
"The planet has a similar mass to Saturn, but its radius is similar to Jupiter, so it's quite a puffed up planet. Because its host star is so cool it's not heating the planet up so much, it's very different from the planets we have observed so far," Mr Zhou said.
"The atmosphere of this planet will be an interesting target for future study."
The research is published in the Astronomical Journal.
Explore further: Perth's planet hunter helps discover unusual exoplanet
More information: "HATS-6b: A Warm Saturn Transiting an Early M Dwarf Star, and a Set of Empirical Relations for Characterizing K and M Dwarf Planet Hosts," 2015. The Astronomical Journal 149 166. DOI: 10.1088/0004-6256/149/5/166
Journal reference: Astronomical Journal
An artist's impression of HATS-6. Credit ANU
George Zhou at the Hawaiian Mauna Kea observatory. Credit: Daniel Bayliss
EXO-PLANET Ping!...............
Did they name it "Planet Hollywood?"
Sounds like a typical hot Jupiter orbiting a typical M-dwarf.
Clearly this must be a European Expoplanet, because everyone knows African Exoplanets are non-migratory
Well done!
Mexican Exoplaneta...........
It’s probably just a space ship.
I sometimes wonder if our solar system had a giant planet close to the sun and at some time in the distant past but it was gobbled up by the sun.
It could be when a large planet smashes intot he sun it creates an explosion of debris through the entire solar system which then leads to terrestrial planet building.
There’s an interesting program on the Discovery channel called ‘How the Universe Works’...they had an episode on that posited an explanation of how a Jupiter-like planet could have gotten so close to the parent star...it seems the enormous gravity of the star and the planet create a harmonic convergence wave, similar to ripples in a pond when you throw in a stone, that the planet ‘rides’ inbound; sound like this might be a similar situation, if this isn’t indeed the star/planet they were talking about on the show; sounded plausible enough, I guess.
“but our theories can’t explain how this happened.”
ah yes the comfort of settled science
on the other hand.... “In the beginning...”
It surfed in on a Gravity Wave....................dude..........
A Dyson sphere in a binary system
It seems to me that virtually EVERYTHING in the universe requires something else for its existence.
A system of two or more things that work together,if one were missing the other would not exist.
From Galaxy’s to Solar systems to Life on Earth.
ah the fragility of symbiosis
and yet “In the beginning.....”
John 1:1
“Does this exoplanet make me look fat?”
Maybe Obama will have a proposal in the next State of the Union address. Maybe just a few billion for a pilot study to begin with....
Maybe Obama will have a proposal in the next State of the Union address. Maybe just a few billion for a pilot study to begin with....
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