This marks the first discovery of another system of planets that has striking similarities with our Solar System. Moreover, it suggests that such giant planets do not favour the single-life but are more likely to be found in family groups. The research is published in the 15th February issue of Science.
Whilst there are more than 250 planets now known, there are only about 25 such systems with multiple planets and the newly discovered system resembles our own Solar System more closely than any previously observed.
Dr Martin Dominik, Royal Society University Research Fellow at the University of St Andrews, points out "Our gravitational microlensing technique is currently best suited for studying extra-solar planets that resemble the gas giants of the Solar System at their respective orbital radii, given that we do not need to wait for many years for them to complete their orbit."
The two newly discovered planets have revealed their existence through characteristic signatures in the received light during the gravitational microlensing event OGLE-2006-BLG-109. Rather than orbiting the observed star, these are associated with an unseen foreground star, systematically designated OGLE-2006-BLG-109L (where 'L' stands for 'lens), whose gravitational field (together with that of the planets) bent the light of the observed background star, with which it happened to be closely aligned.
While planet OGLE-2006-BLG-109Lb with 0.71 Jupiter masses is 2.3 times as far from its host star as the Earth is from the Sun, the less massive OGLE-2006-BLG-109Lc, 0.27 times the mass of Jupiter resides at twice the distance from its host star as its fellow companion.
Despite of the fact that their host star is only half as massive as the Sun, and therefore cooler, the OGLE-2006-BLG-109L planetary system otherwise bears a remarkable similarity to our Solar System. Both the ratio between the two masses of the detected giant planets (close to 3:1) and the ratio between their orbital radii (1:2) are remarkably similar to those of Jupiter and Saturn. Similarly, the ratio between the orbital periods of 5 years and 14 years, respectively, resembles that between Jupiter and Saturn (2:5).
More hidden planets?
Due to the lack of respective signatures, additional gas-giant planets more massive than Saturn can only reside in orbits smaller than that of Venus or substantially wider than that of OGLE-2006-BLG-109Lc. This leaves the plausible possibility for terrestrial planets (like Mercury, Venus, Earth, and Mars) to reside inside the orbit of OGLE-2006-109Lb, which is likely to be the innermost giant planet. Moreover, planets taking the roles of Uranus and Neptune, respectively, could also be present. These features make the OGLE-2006-BLG-109L system the most similar to the Solar System amongst the about 25 exo-planetary systems discovered so far.
Given that we already know from observations that not all stars host gas-giant planets, and that the detection of each of them is not guaranteed, the double catch around OGLE-2006-BLG-109L suggests that they come as hierarchic systems rather than as lonesome objects. Dr Nicholas Rattenbury, STFC-funded Postdoctoral Research Associate at the Jodrell Bank Centre of Astrophysics, points out: "Like humans, gas-giant planets appear to prefer not to come as lonely hearts."
The contributing observations with the Liverpool Telescope (LT) were carried out as part of the RoboNet microlensing programme, whose principal investigator, Prof Keith Horne from the University of St Andrews remarks "The flexible scheduling and short response time of robotic telescopes is ideally suited to carry out a time-critical programme like the search for extra solar planets by microlensing." Apart from the Liverpool telescope, RoboNet exploits two further identical robotic telescopes with a diameter of 2m, the largest of their kind.
The RoboNet microlensing programme is spread over the network by means of intelligent-agent technology built by the eSTAR (e-Science Telescopes for Astronomical Research) Project. Dr Alasdair Allan from the University of Exeter, one of the core developers of eSTAR, explains "Single isolated telescopes are rapidly being integrated into expanding smart telescope networks, spanning continents and responding to transient events in seconds. These time-critical observations can be optimally scheduled across the network using Intelligent Agent technology which negotiates a contract for the observations with the remote telescopes".
The UK microlensing planet hunters are now preparing to boost their capabilities by adopting a fully-automated three-step approach of survey, follow-up, and anomaly monitoring. Enabled by the ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search) expert system that determines the optimal target to be followed at any given time for any observing site, ground-based observations with a global network of telescopes could not only lead to the first detection of an Earth-mass extra-solar planet, but even of less massive ones.
Dr Dominik concludes: "While most planetary systems around other stars substantially differ from the Solar system, a series of recent detections have brought us closer and closer to home. Sooner rather than later, someone can be expected to discover an Earth-mass planet orbiting a star other than the Sun - and it could be us."
Prof Horne adds, "Apart from individual spectacular discoveries, the technique of gravitational microlensing allows to infer a census of planets within the Milky Way. Once we know that planets similar to Earth are common, it is straightforward to go ahead on finding them and investigating whether these harbour any forms of life."
Timeline of a global discovery26 March 2006:
Summary of Planet PropertiesOGLE-2006-BLG-109LbOGLE-2006-BLG-109LcJupiterSaturn
Julia Maddock | alfa
Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center
Supermassive black hole model predicts characteristic light signals at cusp of collision
15.02.2018 | Rochester Institute of Technology
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy