Scientists discover dozens of small celestial bodies every night
Astronomical research on asteroids, i.e. minor planets, is also benefiting from the large-scale Gaia mission of the European Space Agency (ESA). Even though the astrometry satellite’s main purpose is to precisely measure nearly one billion stars in the Milky Way, it has tracked down a multitude of minor planets in our solar system. To determine its current position in space and thus ensure Gaia’s extremely high measurement accuracy, images are taken every day of the regions of the sky where the very faint satellite is located.
“Each night the images reveal several dozen minor planets. The data are quite valuable for our understanding of the origin of our solar system,” says Dr. Martin Altmann of the Institute for Astronomical Computing (ARI), which is part of the Centre for Astronomy of Heidelberg University.
Dr. Altmann heads the observation programme to determine the position of the Gaia satellite for the Data Processing and Analysis Consortium (DPAC), which is responsible for evaluating the data from Gaia.
The Gaia astrometry satellite, which has been fully operational since August 2014, measures with pinpoint accuracy the positions, movements and distances of stars in the Milky Way, thereby furnishing the basis for a three-dimensional map of our home galaxy. According to Dr. Altmann, it became clear during preparation for the Gaia mission that the ambitious accuracy goals required novel methods to determine the position and velocity of the satellite itself.
For this purpose an observation campaign was launched to determine Gaia’s position and velocity from Earth. As early as 2009, Dr. Altmann of the ARI and his colleague Dr. Sebastien Bouquillon of the Observatoire de Paris (France) began planning the programme together with an international team.
Among the partners for the implementation, they attracted observatories in Chile and Spain. The Institute for Astronomical Computing is responsible for coordinating the daily observations. Since the launch of Gaia in December 2013, Gaia’s ground-based position measurements are transmitted regularly to mission control, the European Space Operations Centre in Darmstadt.
Dr. Altmann explains that the astrometry satellite is at a distance of approximately 1.5 million kilometres and is always located in the region of space away from the Sun as viewed from the Earth. “For this reason Gaia’s positioning images are also perfect for observing minor planets. This so-called oppositional position brings these celestial bodies closer to Earth, making them appear brighter than at other times,” continues the Heidelberg researcher.
More than 2,000 small planets have been found this way since the beginning of this year, mainly on images from the VST telescope of the European Southern Observatory (ESO) in Chile. Dr. Altmann indicates that nearly 40 per cent of them are new discoveries. Moreover, these current measurements are especially interesting for already known minor planets as well, precisely because Gaia and the minor planets located in the same part of space are always opposite the sun at the time of observation.
Just like with the full moon, the planets’ entire earthward side is completely illuminated only at that location. This allows the researchers to measure the asteroid’s reflectivity very accurately and draw conclusions as to their chemical composition. Up to now only approximately 30 asteroids have their reflectivity sufficiently well-determined, according to Dr. Altmann.
The Gaia astrometry satellite itself will also discover and accurately measure many asteroids in its survey of the sky, but in totally different regions. “In this respect, the observations from the Gaia mission and the ground-based measurements complement each other extremely well,” says Dr. Altmann. “We hope not only to acquire new insight into the origins of our home galaxy through the Gaia satellite mission. We will certainly learn more about the origins of our solar system,” stresses Prof. Dr. Stefan Jordan of the Institute for Astronomical Computing, whose responsibilities also include public relations for the DPAC Consortium.
Dr. Guido Thimm
Centre for Astronomy of Heidelberg University
Phone: +49 6221 54-1805
Communications and Marketing
Press Office, phone: +49 6221 54-2311
Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
K-State study reveals asymmetry in spin directions of galaxies
03.06.2020 | Kansas State University
The cascade to criticality
03.06.2020 | ETH Zurich Department of Physics
An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links...
Two prominent X-ray emission lines of highly charged iron have puzzled astrophysicists for decades: their measured and calculated brightness ratios always disagree. This hinders good determinations of plasma temperatures and densities. New, careful high-precision measurements, together with top-level calculations now exclude all hitherto proposed explanations for this discrepancy, and thus deepen the problem.
Hot astrophysical plasmas fill the intergalactic space, and brightly shine in stellar coronae, active galactic nuclei, and supernova remnants. They contain...
In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".
Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...
Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.
researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...
Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.
When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...
19.05.2020 | Event News
07.04.2020 | Event News
06.04.2020 | Event News
03.06.2020 | Medical Engineering
03.06.2020 | Physics and Astronomy
03.06.2020 | Physics and Astronomy