Astronomers find evidence for a strange new planetary system

Jun 21, 2011
An artist’s impression of the binary UZ For and planet

(PhysOrg.com) -- A team of astronomers, including Dr Gavin Ramsay of the Armagh Observatory, has found evidence that suggests the existence of an extraordinary planetary system. Two giant planets appear to be revolving at some distance around a compact, interacting stellar binary known as UZ For, which comprises two small stars orbiting very closely one about the other.

If confirmed, this would be an example of a very strange new , given the nature of the stellar pair. The two stars, one a white dwarf and the other a red dwarf, are each smaller than our Sun and are orbiting in such close proximity that they take only a couple of hours to complete one revolution. The stellar pair would actually fit comfortably inside our Sun! By chance, the system is oriented in such a way that the stars pass in front of one another every orbit as seen from Earth, producing mutual eclipses that allow the properties of the system to be very well determined.

But the researchers noticed that the eclipses were not occurring precisely on time. Instead, they were sometimes too early and sometimes too late. This led them to suggest the presence of two , whose gravitational tugs would cause the orbits of the stars to "wobble" in space and so slightly change the measured time between eclipses. According to their calculations, the masses of the two planets would have to be at least eight and six times that of Jupiter, and they would have to take respectively five and sixteen years to orbit the two central stars. The system is too far away for these planets to be directly imaged.

The interacting system, which is called UZ For because of its location in the southern constellation of Fornax, produces an extremely inhospitable environment for planets. Due to their close proximity, the gravity of the more massive, but much more compact white dwarf star is constantly "stealing" material from the surface of the red dwarf in a continuous stream. This stream of material collides with the surface of the white dwarf, where it is heated to millions of degrees Kelvin, flooding the entire planetary system with enormous amounts of deadly X-rays.

The discovery was made using new observations from the Southern African Large Telescope (SALT) together with archival data spanning 27 years gathered from multiple observatories and Earth-orbiting satellites. The Armagh Observatory has access to SALT through its membership of the UK SALT Consortium. Astronomy at Armagh is supported by core funding from the Northern Ireland Department of Culture, Arts and Leisure.

Explore further: The entropy of black holes

More information: The research has been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society, under the title "Possible detection of two giant extrasolar planets orbiting the eclipsing polar UZ Fornacis". The authors are: Steve Potter, Encarni Romero Colmenero (South African Astronomical Observatory), Gavin Ramsay (Armagh Observatory) and a number of others. A pre-print can be seen here.

Provided by Armagh Observatory

4.9 /5 (13 votes)

Related Stories

Astronomers find 'snooker star system'

Nov 09, 2010

Astronomers at The University of Warwick and the University of Sheffield have helped discover an unusual star system which looks like, and may even once have behaved like, a game of snooker.

A sub-stellar Jonah: Brown dwarf survives being swallowed

Aug 02, 2006

Using ESO's Very Large Telescope, astronomers have discovered a rather unusual system, in which two planet-size stars, of different colours, orbit each other. One is a rather hot white dwarf, weighing a little bit less than ...

Recommended for you

The entropy of black holes

Sep 12, 2014

Yesterday I talked about black hole thermodynamics, specifically how you can write the laws of thermodynamics as laws about black holes. Central to the idea of thermodynamics is the property of entropy, which c ...

Modified theory of dark matter

Sep 12, 2014

Dark matter is an aspect of the universe we still don't fully understand. We have lots of evidence pointing to its existence (as I outlined in a series of posts a while back), and the best evidence we have point ...

Gaia discovers its first supernova

Sep 12, 2014

(Phys.org) —While scanning the sky to measure the positions and movements of stars in our Galaxy, Gaia has discovered its first stellar explosion in another galaxy far, far away.

Astronomers unveil secrets of giant elliptical galaxies

Sep 12, 2014

New findings of how giant elliptical galaxies move have been discovered by an international team of astronomers using the newly installed Multi Unit Spectroscopic Explorer (MUSE) at the European Southern Observatory's (ESO) ...

Exploring the cosmic X-ray background

Sep 12, 2014

You are likely familiar with the cosmic microwave background. This background is a thermal remnant of the big bang. Because of the expansion of the universe, this remnant energy has a temperature of about ...

User comments : 13

Adjust slider to filter visible comments by rank

Display comments: newest first

pt30
2.1 / 5 (15) Jun 21, 2011
Quote: "..where it is heated to millions of degrees Kelvin..."

It should be noted that Kelvins are a unit of measurement. You don't go around writing, "the Sun is millions of kilometers miles from the Earth..."

Come on, Physorg!
jamesrm
2.5 / 5 (8) Jun 21, 2011
Degrees Kelvin, Degrees Celsius, Degrees Fahrenheit

Millions of Kilo-metres, Giga-metres

:o*
SCVGoodToGo
2.3 / 5 (6) Jun 21, 2011
Centigrade and Kelvin are NOT in degrees as pt30 points out. Only Fahrenheit and Rankine are expressed in degrees (and I'm not so sure on the latter).
Sanddog
5 / 5 (5) Jun 21, 2011
From Wikipedia:
"Unlike the degree Fahrenheit and degree Celsius, the kelvin is not referred to or typeset as a degree."

from Kelvin to Kelvin
Celsius [°C] = [K] 273.15 [K] = [°C] + 273.15
Fahrenheit [°F] = [K] × 95 459.67 [K] = ([°F] + 459.67) × 59
Rankine [°R] = [K] × 95 [K] = [°R] × 59
For temperature intervals rather than specific temperatures,
1 K = 1 °C = 1.8 °F = 1.8 °R
Comparisons among various temperature scales
lengould100
4 / 5 (5) Jun 21, 2011
That seems a wierd convention, as Kelvin are simply Celcius offest 273.15 . If "Degrees C", why not "Degrees K"?
pauljpease
3.8 / 5 (4) Jun 21, 2011
That seems a wierd convention, as Kelvin are simply Celcius offest 273.15 . If "Degrees C", why not "Degrees K"?


Because the unit of temperature on the absolute scale in the SI system is "Kelvin", not "degrees Kelvin". That's what it's called. And "degrees" was probably dropped because it's unnecessary and nobody likes to have to add special characters such as the degree symbol when writing about science.
that_guy
3 / 5 (2) Jun 21, 2011
and you all seem to know what the article is trying to say whether or not the author says "degrees" or not.

Anyways, it seems that this strange or extraordinary system is doomed to die soon in a type 1a supernova.
ColossusVSGuardian
5 / 5 (1) Jun 21, 2011
How did it form? I dont think it could of formed without an external force.I wonder if a pair of accretion discs became entwined, or if they were already fully formed solar systems. Bet there were some fireworks that day.
Shootist
1 / 5 (2) Jun 21, 2011
So what happens if the barycenter is exterior to both stars, while their orbit is close enough for one star to steal material from the other?
James_Hager
5 / 5 (2) Jun 21, 2011
ok for those who dont know, kelvin and celsius the -273 conversion, each unit expresses the same amount of heat per unit, so 1 celsuis unit measures the same as 1 kelvin unit, kelvins units are just offset by -273, -273 celsuis is absolute 0 the temp where all subatomic motion stops...celsius 0 is set to water freezing, kelvins 0 is set to absolute 0...but on a point for point bases the heat/unit is the same amount just the start of 0 is different in the 2...and kelvin, celsius, and fahrenheit all use degrees, degrees isnt a unit itself lol
HannesAlfven
1 / 5 (4) Jun 22, 2011
Within the electrical framework, stars split when exposed to exceptional electrical stress. They do this in order to increase their surface area, which effectively decreases the electrical stress.

The inference of an external gravitational distortion from rotating planets is possibly unnecessary within this other view.

It may turn out that the reason the eclipses aren't perfectly timed is due to some sort of slow-motion separation of the two bodies. Or, there may be a sudden change in the entire system's stability due to the fact that the number of bodies has changed.

I'm surprised that there is no observable energetic event which preceded the separation. I wonder what led the researchers to observe it, to begin with ...
StandingBear
1 / 5 (1) Jun 22, 2011
I believe that the article was about a binary star system. Nowhere in that article is any real reference to temperature units. This semantics backache about degrees and definitions is not germane to the article and does not belong in this discussion. At issue is a serious atronomical observation whose discussion is being sidetracked and effectively hyjacked. Binary starsystems are the most prevalent stable basic astronomical phenomena in the universe as we usually observe, and their study is important.
Ramael
not rated yet Jun 30, 2011
The first half dozen comments are pointless. Egotistic competitions of scientific penis size, as though the winner is deemed the smartest and greatest. In reality all your doing is announcing how small in inadequate you really feel.