A raw Carmenes visible spectrum of the Luyten's star. Carmenes covers the reddest part of the visible spectrum and a part of the near infrared, which is invisible to human eyes. The Luyten's star (GJ 273) is a cool, red M dwarf at only about twelve light-years to our Solar System. It emits most of its radiation in the wavelength region covered by Carmenes.
A portion of the extracted Carmenes red optical spectrum of the Luyten's star (blue) overimposed on the spectrum of our visible Fabry-Pérot etalon (red). The spectra of stars are like their fingerprints and allow astronomers to know their properties and composition. A displacement of the blue lines in respect to the red ones would indicate a radial-velocity shift led by a planetary companion.
University of Göttingen scientists participate in development of new spectrograph
(pug) Information on Earth-like planets – that is what scientists hope to get from Carmenes, a new highly complex spectrograph. After five years of preparation, the outstanding astronomical instrument has now successfully passed first “on sky” tests at the telescope of the Calar Alto Observatory in southern Spain. It consists of two spectrographs to analyze the visible and the infrared light coming from celestial bodies. Both have been optimized for the discovery of planets orbiting nearby stars. Thus, Carmenes will be an important milestone for one of the most exciting areas of space exploration – the search for a second Earth. It was developed and constructed by eleven partners in Spain and Germany, including Göttingen University’s Institute for Astrophysics.
Carmenes specializes in detecting planets orbiting so-called M dwarfs. These are very small stars, which offer temperate conditions for planets in close orbits. M dwarfs emit most of their light in the near infrared part of the electromagnetic spectrum – a part that Carmenes is sensitive to like no other instrument at this point in time. Furthermore, due to its cutting edge technology Carmenes is able to detect the smallest shifts and changes in the movement of a star. This allows scientists to draw conclusions about the possible existence of a planet.
“The combination of data from two spectrographs will provide us with much more information than any previous similar instrument,” explains Prof. Ansgar Reiners from Göttingen University’s Institute for Astrophysics. “This will help discriminate spots on the surface of the stars from orbital motion caused by planetary companions. We are therefore hopeful that we will discover dozens of potentially habitable planets in the coming years.”
The researchers from Göttingen University hope to be able to acquire scientific data starting January 1, 2016. In the development phase of the project, they were responsible for adapting the spectrographs to the scientific problems addressed as well as for the two van-sized vacuum tanks that protect the spectrographs from outside influences. Furthermore, the data processing software was programmed at Göttingen University. The project applies new methods of calibration that were developed at the Institute for Astrophysics. Further information is available online at https://carmenes.caha.es.