![]() The drastic difference between “face-on” vs “edge-on” appearance, which has to do with our viewing angle of WR 112, is demonstrated in the figure and animations below.įigure 2: Model of the WR 112 nebula from a face-on viewing angle (left) and the observed viewing angle (right). The models and the series of imaging observations revealed that the rotation period of this dusty “edge-on” spiral (and the orbital period of the central binary system) is 20 years. The appearance of the model images shows a remarkable agreement with the real images of WR 112. The animation above shows a comparison between the models of WR 112 created by the research team alongside the actual mid-IR observations. The animation pauses at each phase that is displayed in the real observations. The φ symbol on the model animation indicates the orbital phase of the central binary, where φ = 0 is at the beginning of its 20-yr orbit, and φ = 1 is at the end of its orbit. “I shared the images of WR 112 with Peter and Yinuo, and they were able to produce an amazing preliminary model that confirmed that the dusty spiral stream is revolving in our direction along our line of sight,” said Lau.Īnimation 1: Animated model of the spiral dust nebula around WR 112 (left) and the actual corresponding observations (right). Peter Tuthill and undergraduate Yinuo Han, who are experts at modeling and interpreting the motion of the dusty spirals from binary systems like WR 112. Lau collaborated with researchers at the University of Sydney including Prof. It confused me so much that I couldn’t sleep after the observing run-I kept flipping through the images until it finally registered in my head that the spiral looked like it was tumbling towards us.” “To my surprise, the COMCIS image revealed that the dusty shell had definitely moved since the last image we took with the VLT in 2016. “We published a study in 2017 on WR 112 that suggested the dusty nebula was not moving at all, so I thought our COMICS observation would confirm this,” explained lead author Ryan Lau (ISAS/JAXA). After almost 20 years uncertainty on WR 112, images from the COMICS instrument on the Subaru Telescope taken in Oct 2019 provided the final-and unexpected-piece to the puzzle. Decades of multi-wavelength observations presented conflicting interpretations of the dusty outflow and orbital motion of WR 112. However, the dusty nebula around WR 112 is far more complex than a simple pinwheel pattern. WR 104, in particular, reveals an elegant trail of dust resembling a ‘pinwheel’ that traces the orbital motion of the central binary star system. This binary dust formation phenomenon has been revealed in other systems such as WR 104 by co-author Peter Tuthill ( University of Sydney). This dust formation process is exactly what is occurring in WR 112. ![]() “When the two winds collide, all Hell breaks loose, including the release of copious shocked-gas X-rays, but also the (at first blush surprising) creation of copious amounts of carbon-based aerosol dust particles in those binaries in which one of the stars has evolved to He-burning, which produces 40% C in their winds,” says co-author Anthony Moffat (University of Montreal). However, interesting things happen when the fast winds of two massive stars in a binary interact. (Credit: NAOJ and ISAS/ JAXA)ĭust formation, which is typically seen in the gentle outflows from cool stars with a Sun-like mass, is somewhat unusual in the extreme environment around massive stars and their violent winds. The lead author Ryan Lau introduces the highlights of the research results. The study reveals the motion of the dusty outflow from the system and identifies WR 112 as a highly efficient dust factory that produces an entire Earth mass of dust every year. ![]() Dust is expected to be formed in the region where stellar winds from these two stars are colliding. ![]() WR 112 is a binary system composed of a massive star in the very late stage of stellar evolution losing a large amount of mass and another massive star at the main sequence. Massive binary star systems, as well as supernova explosions, are regarded as sources of dust in the Universe from its early history, but the process of dust production and the amount of the ejected dust are still open questions. With almost two decades of mid-infrared (IR) imaging from the largest observatories around the world including the Subaru Telescope, a team of astronomers was able to capture the spiral motion of newly formed dust streaming from the massive and evolved binary star system Wolf-Rayet (WR) 112. The length of the white line on each image corresponds to about 6800 astronomical units. Sequence of 7 mid-IR (~10 micrometers) images of WR 112 taken between 2001 – 2019 by Gemini North, Gemini South, Keck, the Very Large Telescope (VLT), and the Subaru Telescope.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |