Now by analyzing its velocity, light intensity, and for the first time its tell-tale elemental composition, Carnegie astronomers Alceste Bonanos and Mercedes López-Morales, and collaborators Ian Hunter and Robert Ryans from Queen’s University Belfast have determined that it came from our neighboring galaxy, the Large Magellanic Cloud (LMC).
The result suggests that it was ejected from that galaxy by a yet-to-be-observed massive black hole. The research will be published in an upcoming issue of the Astrophysical Journal Letters.
The star, dubbed HE 0437-5439, is an early-type star and one of ten so-called hypervelocity stars so far found speeding away from the Milky Way. “But this one is different from the other nine,” commented López-Morales. “Their type, speed, and age make them consistent with having been ejected from the center of our galaxy, where we know there is a super-massive black hole. This star, discovered in 2005*, initially appeared to have an elemental makeup like our Sun’s, suggesting that it, too, came from the center of our galaxy. But that didn’t make sense because it would have taken 100 million years to get to its location, and HE 0437-5439 is only 35 million years old.”
To explain the enigma, or “paradox of youth,” the discoverers proposed that HE 0437-5439 was either a so-called blue straggler—a relatively young, massive star resulting from the merger of two low-mass stars from the Milky Way, or it originated from the Large Magellanic Cloud.
“We were intrigued by the conundrum and decided to take up the challenge to solve this,” stated Bonanos. “Stars in the LMC are known to have lower elemental abundances than most stars in our galaxy, so we could determine if its chemistry was more like that galaxy’s or our own.”
The team confirmed results of the previous study concerning the mass, age, and speed of the star. It is about nine times the mass of our Sun, about 35 million years old, and it is zooming away from the Milky Way and Large Magellanic Cloud into intergalactic space at 1.6 million miles per hour (2.6 million km/hour).
Although the previous study was able to roughly estimate the star’s elemental composition, the measurements were not detailed enough to determine if the elements match stars in our galaxy, or are characteristic of stars from the Large Magellanic Cloud. These astronomers were able to measure the relative abundances of certain elements for the first time in any hypervelocity star. The relative abundance of key elements tells them where a star originated.
“We’ve ruled out that the star came from the Milky Way,” explained Bonanos. “The concentration of elements in Large Magellanic Cloud stars are about half those in our Sun. Like evidence from a crime scene, the fingerprints point to an origin in the Large Magellanic Cloud.”
Based on the speed of the star’s rotation measured by the discoverers, and confirmed by this team, the astronomers believe that the star was originally part of a binary system. The binary could have passed close to a black hole 1,000 the mass of the Sun**. As one star was pulled into the black hole, the other was whipped into frenzy and flung out of the galaxy.
“This is the first observational clue that a massive black hole exists somewhere in the LMC. We look forward to finding out where this black hole might be,” concluded Bonanos.
Alcestes Bonanos | EurekAlert!
Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center
Supermassive black hole model predicts characteristic light signals at cusp of collision
15.02.2018 | Rochester Institute of Technology
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy