On Thursday evening, at the time of its closest approach to the sun, comet ISON still had an active nucleus which was spewing gas and dust. About two hours after the Perihelion passage, however, there were no longer indications for any output.
The remains of ISON: On this image taken by satellite Soho, a tail-like structure is moving away from the sun. But now the comet is fading.
© ESA / NASA / SOHO
This is the assessment made by scientists at the Max Planck Institute for Solar System Research in Katlenburg- Lindau on Saturday. They analysed actual pictures of the instrument LASCO which enjoys a unique view of the comet from its vantage point on board of the Solar Observatory SOHO.
On current photographs, the brightness of the apparently inactive comet is gradually decreasing. It is almost certain that there won't be a spectacular comet display after all.
Against 8:30 p.m. yesterday evening, the tail of ISON emerged from behind sun in the field of view of the LASCO instrument. At this point in time, however, it was unclear whether the tip of the tail concealed a nucleus or not. Pictures taken a few hours after Perhelion now allow further conclusions to be drawn.
"The dust tail of the comet is now divided into two parts," explains Hermann Böhnhardt from the Max Planck Institute for Solar System Research. According to Böhnhardt, the part of the tail that is pointing towards the sun consists of dust particles, which were released significantly before the comet's Perihelion passage – i.e. prior to reaching the closest point to the sun.
The other part, however, appears to contain more recent material: It was released when ISON passed the sun and suggests that at least part of the nucleus still existed and was active at that time.
The Max Planck researchers base their assessment on computer simulations in which they model the shape of the dust tail. "If we assume in our calculations that the comet has emitted dust at Perihelion, we can reproduce the current images quite well," says Böhnhardt.
The LASCO images from Saturday showed the ISON stopped producing dust two hours after Perhelion. Whether the comet nucleus was still intact at Perihelion or continued its flight as a small fragment or as collection of chunks is not yet clear.
The instrument Sumer on board of the satellite SOHO, which was developed and built under the auspices of the Max Planck Institute in Lindau observed ISON on Thursday night in the hour when it directly approached the sun. The instrument divides the light that is sent into space by the celestial body into its individual components. From this, researchers can draw conclusions about the elements and molecules in the comet's dust cloud.
"Our measurements show a clear signal of the comet during its flight past the sun," says Max Planck scientist Werner Curdt. Exact results of the measurement, however, are not yet available.
ContactDr. Birgit Krummheuer
Dr. Birgit Krummheuer | Max-Planck-Institute
A tale of two pulsars' tails: Plumes offer geometry lessons to astronomers
18.01.2017 | Penn State
Studying fundamental particles in materials
17.01.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
18.01.2017 | Power and Electrical Engineering
18.01.2017 | Materials Sciences
18.01.2017 | Life Sciences