An Exoplanet with a Potassium-Rich Atmosphere

Mar 04, 2011
An image of Jupiter next to a artist's conception of the exoplanet XO-2b. Scientists have discovered that the atmosphere of XO-2b contains potassium. Credit: Ignacio González Tapia

( -- A hot Jupiter - a type of celestial object unknown only fifteen years ago - is a Jupiter-sized exoplanet orbiting so close to its host star that its atmospheric temperature is thought to be hundreds of degrees Celsius.

When a hot is seen in a transiting system, its passage across the face of the star provides an opportunity to study its atmosphere, as light from the star passes through the thin layer on route to Earth.

The atmospheres of two hot Jupiters have been studied so far, with sodium (but only sodium) detected.

The constituents and their properties are interesting in and of themselves, and also shed light on global parameters of the planet such as , thermal inversion layers, and the possible presence of clouds.

CfA Jean-Michel Desert has teamed up with ten colleagues to use the 10.4-meter telescope in the Canary Islands to study the atmospheres of transiting hot Jupiters.

The astronomers have just announced their results on the object known as XO-2b, a hot Jupiter whose radius is the same as Jupiter's, whose mass is about half, and which orbits its star in only 2.6 days.

They discovered that the atmosphere contains potassium, one of the elements that had been predicted to exist in current models but which had not been seen in the other two cases.

The new results help to substantiate and improve the current theory of exoplanetary atmospheres, and illustrate the dramatic advances underway in detecting and modeling the atmospheres around strange distant worlds that were unknown not long ago.

Explore further: Hubble traces the halo of a galaxy more accurately than ever before

Related Stories

X-Ray observations of an extrasolar planetary system

Oct 22, 2010

( -- The majority of extra-solar planets (about 278 of them) are more massive than Jupiter. About 20% of this majority group orbit their stars at a distances of less than one-tenth of an astronomical ...

First temperate exoplanet sized up (w/ Video)

Mar 17, 2010

( -- Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first “normal” exoplanet that can be studied in great detail. Designated Corot-9b, ...

COROT's exoplanet hunt update

May 22, 2008

Two new exoplanets and an unknown celestial object are the latest findings of the COROT mission. These discoveries mean that the mission has now found a total of four new exoplanets.

Superhot Planet Likely Possesses Comet-like Tail

Jul 15, 2010

( -- As if the debate over what is and what is not a planet hasn't gotten confusing enough, Hubble Space Telescope astronomers have now confirmed the existence of a tortured, baked object that ...

Recommended for you

Fermi finds a 'transformer' pulsar

9 hours ago

( —In late June 2013, an exceptional binary containing a rapidly spinning neutron star underwent a dramatic change in behavior never before observed. The pulsar's radio beacon vanished, while at ...

Transiting exoplanet with longest known year

Jul 21, 2014

Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days. In comparison, Mars orbits our Sun once every 780 days. Most of the 1,800-plus ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

1.7 / 5 (3) Mar 05, 2011

Potassium [K, element #19] is not an abundant element.

In 1917 Harkins* reported that seven elements with even atomic numbers (Fe, O, Ni, Si, Mg, S and Ca) comprise 99% of the material in ordinary meteorites.

He correctly concluded ... in the evolution of elements much more material has gone into the even-numbered elements than into those which are odd... [Harkins, p. 869].

*Harkins, W. D. The evolution of the elements and the stability of complex atoms, Journal of the American Chemical Society, vol. 39, 1917, pp. 856-879.

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
not rated yet Mar 07, 2011
It might just be me. When H goes to He, the number becomes even... When more He-atoms are combined, it will always resume to be even numbers. Might this not just be the explanation?
1 / 5 (2) Mar 08, 2011
It might just be me. When H goes to He, the number becomes even... When more He-atoms are combined, it will always resume to be even numbers. Might this not just be the explanation?

Yes, He-fusion produced C-12, O-16, Ne-20, Mg-24, Si-28, S-32, Ar-36 etc.

These elements with even atomic numbers (6, 8, 10, 12, 14, 16, 18) generally have greater nuclear stability and more isotopes than elements with odd atomic number (e.g., 7, 9, 11, 13, 15 and 17) for N, F, Na, Al, P, and Cl.

This subject is discussed in more detail here [1,2]:

1. "Why the model of a a Hydrogen-filled Sun is obsolete"

2. "Neutron Repulsion," The APEIRON Journal in press (2011), 19 pages