Violent events leading up to the death of a star could alienate any planet. Newly discovered Thursday-Size object star may have been dead for a long time.

An international team of used astronomers NASATransiting Exoplanet Survey Satellite (TESS) And the retired Spitzer Space Telescope reported to be the first planet to orbit White dwarf, A dense remnant of a Sun-like star is only 40% larger than Earth.

The Jupiter-sized object, known as WD 1856b, is seven times larger than the dwarf and was named WD 1856 + 534. It orbits this stellar cinder every 34 hours, 60 times faster than Mercury orbits our Sun.

How can a giant planet survive the violent process of turning its parent star into a white dwarf? Astronomers have had some ideas since the discovery of Jupiter-sized object WD 1856 b. Attribution: NASA /JPL-Coltech / NASA’s Goddard Space Flight Center

“WD 1856b was somehow very close to its white dwarf and was able to remain in one piece,” said Andrew Vanderberg, an assistant professor of astronomy at the University of Wisconsin-Madison. “The white dwarf creation process destroys nearby planets, and then anything that comes too close is usually torn apart by the star ‘s extreme gravity. We still have many questions as to how WD 1856b got to its current location.

An essay on the system, led by Wonderberg and co – authored by NASA, will appear in the September 16, 2020 issue. Nature.

TESS monitors large parts of the sky, called sectors, for about a month. This foresight allows the satellite to detect exoplanets or worlds beyond our solar system, capturing changes in stellar brightness that occur when a planet passes or transits in front of its star.

The WD 1856b satellite, 80 light-years away, was discovered in the northern constellation Draco. Across 11,000 miles (18,000 km), it orbits a cool, quiet white dwarf, a distant member of a triple star system, up to 10 billion years old.

When a star like the Sun runs out of fuel, it swells hundreds to thousands of times its original size and forms a cool red giant star. Gradually, the outer layers of its gas are expelled, losing up to 80% of its mass. The remaining hot core turns into a white dwarf. Any nearby objects are usually immersed and ignited in this process, and the system would have incorporated WD 1856b into its current orbit. Vanderburgh and his colleagues estimate that it is possible to be at least 50 times farther away from the present location of the planet.

We have long known that after the birth of white dwarfs, distant small objects such as asteroids and comets are scattered inland to these stars. They will be thrown away by the strong gravity of an ordinary dwarf and turn into a debris disk, ”said Xiu Soo, co-author and assistant astronomer at the International Gemini Observatory in Hilo, Hawaii, a program of the National Science Foundation’s NOIRLab. . “That’s why I was so excited when Andrew told me about this system. We saw Indications The planets will scatter inward, but this is the first time we’ve seen a planet that is damaging the entire journey. ”

WD 1856b The team suggests a number of situations that could lead to an elliptical path around the white dwarf. The gravitational pull of the star will stretch the object and over time this path will become more circular and create larger waves that will extend its orbital energy.

“The most likely case involves other Jupiter-sized bodies near the original orbit of WD 1856b,” said Juliette Becker, co-author of 51 Pegasi B Fellows at Caltech Astronomy in Pasadena. “The gravitational pull of large objects can easily allow the instability to push a planet inward. At this point, we still have more theories than data points. ”

The sequential gravitational tug of the other two stars in the system and the red dwarfs G229-20A and B have been around for billions of years, including a flyby from a rogue star that has been affecting the system. Wonderberg’s team thinks these and other explanations are unlikely, because they require well – tuned conditions to achieve the same results as the giant companion planets.

Jupiter-sized objects can only hold a large mass from planets A few times larger than Earth To stars thousands of times the mass of Earth. Others are brown dwarfs that cross the line between the planet and the star. Usually scientists turn to radial velocity observations to measure the mass of an object, which indicates its structure and character. This method works by learning how an orbit connects its star and changes the color of its light. In this case, the white dwarf is too old, its light has become too dim and featureless, and scientists have not been able to find any noticeable changes.

Instead, the team monitored the system with a spitzer in the infrared a few months before the telescope was shut down. If WD 1856b is a brown dwarf or low-mass star, it will emit its own infrared glow. This means that if Spitzer is a planet, it will record a brighter traffic, which will prevent it from emitting light. When the researchers compared Spitzer data with light transit observations taken with the Gran Telescope or Canarias in the Canary Islands of Spain, they found no clear difference. That is, by combining the age of the star and other information about the system, WD 1856b was concluded to be almost 14 times the size of Jupiter. Future research and observations may confirm this conclusion.

The discovery of a world with the potential to orbit the white dwarf prompted co-authors Lisa Kalteneger, Wonderberg, and others to consider the implications of studying the atmosphere of small rock worlds under similar circumstances. For example, suppose an Earth-sized planet is located within the orbit of WD 1856. Using simulated observations, the researchers show that NASA is coming James Webb Space Telescope Water and carbon dioxide can be detected in the imaginary world by observing just five transitions.

The results of these calculations were published at the Cornell University in Itachi, New York, under the direction of Calteneger and Ryan MacDonald. Letters from the Journal of Astronomy Those ones Available online.

“Even more remarkably, the web can find potential gas combinations in only 25 transit to represent such biological activity in the world,” said Kaltenager, director of the Carl Sagan Institute in Cornell. “WD 1856b indicates that the planets will survive the impeccable history of white dwarfs. Under the right circumstances, those worlds can maintain favorable conditions for life More than the predicted time scale for the Earth. We can now explore many interesting possibilities for worlds orbiting these dead star cores. ”

There is currently no evidence that there are other worlds in the system, but there are additional planets that have yet to be discovered. They may have orbits longer than TESS monitors an area or is tipped in a non-transient manner. The white dwarf is also very small, so the chances of catching an infection from planets far from the system are very low.

Reference: Andrew Wonderberg, Saul A. Rappaport, Xiu Soo, Ian JM Crossfield, Juliet C. Becker, Bruce Gary, Philippe Murgas, Simon Bluin, Thomas G. Kay, Enrique Palle, Carl Mellis, Brett M. Morris, Laura Creedberg, Varugen Georgian, Caroline V. Morley, Andrew W. Mann, Hanu Parvianen, Logan A.. Pierce, Elizabeth R .; Newton, Andrea Carillo, Ben Zuckerman, Lone Nelson, Greg Seaman, Warren R. Brown, Rene Tronsgാർrd, Beth Klein, George R .; Ricker, Roland K. Wandererspeak, David W. Latham, Sarah Seeger, Joshua n. Win, John M .; Jenkins, Fred c. Adams a. Buchawe, Douglas A.. Caldwell, Jesse L .; Christiansson, Karen A.. Collins, Knickol d. Natalia M. Guerrero, Seung Guo, Kevin Heng, Andrea I. Henriksen, Chelsea X. Huang, Lisa Calteneger, Stephen R. Issuer, Farisa Morales, Norio Narita, Joshua Pepper, Mark E. Rose, Jeffrey c. Smith, Kievan G.. Stasun, Liang Yu, September 16, 2020, Nature.
DOI: 10.1038 / s41586-020-2713-y

Tess is guided and operated by the NASA Astrophysics Explorer Mission With NASA’s Goddard Space Flight Center manages the Green Belt in Cambridge, Massachusetts, Maryland. Nortrop Gruman, based in False Church, Virginia; NASA’s Ames Research Center in Silicon Valley, California; Harvard-Smithsonian Center for Astrophysics in Cambridge; More than a dozen universities, research institutes and observatories around the world are participating in the mission.

NASA’s Jet Propulsion Laboratory in Southern California oversaw the Spitzer mission for the agency’s Science Mission Directorate in Washington. Spitzer continues to analyze science data through the Spitzer Data Archive, located in the Infrared Science Archive at the Infrared Processing and Analysis Center (IPAC) at Caltech. Conducted scientific work at the Spitzer Science Center in Caltech. The space shuttle operations were centered on Lockheed Martin Space in Littleton, Colorado. Caltech manages JPL for NASA.