Previously, the only way to determine a planet's exact mass was if it transits—has an orbit that periodically eclipses that of its host star. Former Carnegie scientist Mercedes López-Morales has, for the first time, determined the mass of a non-transiting planet. The work is published by Astrophysical Journal Letters.
Knowing a body's mass is essential first to confirm it is a planet and if so, to determine whether it is rocky and possibly habitable or large and gassy. Until now, only the masses of transiting planets have been measured. Transiting planets are also the only type of extra-solar objects on which atmospheres have been detected.
López-Morales, along with her colleagues Florian Rodler and Ignasi Ribas of the Institute of Space Sciences, ICE (CSIC-IEEC, in Barcelona, Spain) measured the exact mass of a non-transiting planet. They did this using a new method that involves studying the carbon monoxide signature of the planet's atmosphere—detecting, in the process, the atmosphere of this non-transiting planet.
The planet is called Tau Boo b, located in the constellation of Bootes, and it orbits a star about 50 light years from Earth that's bright enough to be visible to the naked eye. The planet is similar in size to Jupiter and is so close to its star (only 8 stellar radii), that a year for this planet asts only 3.3 Earth days. Furthermore, its surface temperature reaches 1,500 ° C, making it inhospitable to life.
Discovered in 1996, Tau Boo b was one of the first planets originally detected by the radial velocity method. This planet does not transit, but its presence and characteristics were initially determined by the wobble of its host star. This technique only provides a rough indication of a detected planet's mass.
In June 2011, López-Morales' team conducted five hours of observations at near infrared wavelength (2.3 microns). They obtained data from the high-resolution spectrograph CRIRES, an instrument mounted on one of the four 8.2m Very Large Telescopes (VLT) of the European Southern Observatory (ESO) in Chile.
The observations and subsequent data analysis revealed the presence of carbon monoxide in the planet's atmosphere. In addition, by studying the planet's orbital motion through the displacement of spectral lines of carbon monoxide, the team was able to calculate its exact mass—5.6 times Jupiter—a first using this particular method, and also a first for a non-transiting planet.
An independent study conducted by researchers at the University of Leiden in the Netherlands obtained a similar result for the same planetary system, confirming the potential of this technique.
"This method represents a strong advance in the field of exoplanets," said Lopez-Morales. "It opens a new path to determine masses of exoplanets and the composition of their atmospheres"
The research team expects many more planets will be weighted using this new technique. They are also convinced that in the future, they will be able to detect molecules that are associated with the presence of life in non-transiting distant planets."
This work has been partially supported by the NSF.
The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
Mercedes López-Morales | EurekAlert!
'Frequency combs' ID chemicals within the mid-infrared spectral region
16.03.2018 | American Institute of Physics
Fraunhofer HHI have developed a novel single-polarization Kramers-Kronig receiver scheme
16.03.2018 | Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut, HHI
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences