Chandra detected the short-lived dimming of X-rays from a system where a massive star is in orbit around a neutron star or black hole (shown in the artists illustration). These luminescent systems normally include a neutron star or black hole pulling in gas from a closely orbiting companion star. The neutron star or black hole is pulling material from its companion star, producing a disk of material that glows in X-rays (red, orange, and yellow). This system contains either a neutron star or a black hole in orbit with a star about 20 to 30 times the mass of the Sun (large blue star). The neutron star or black hole is pulling product from its companion star, creating a disk of product that glows in X-rays (red, orange, and yellow).
Exoplanets are defined as planets beyond our Solar System. Up until now, astronomers have discovered all other recognized exoplanets and exoplanet candidates in the Milky Way galaxy, almost all of them less than about 3,000 light-years from Earth. An exoplanet in M51 would have to do with 28 million light-years away, implying it would be thousands of times further away than those in the Milky Way.
A composite image of M51 with X-rays from Chandra and optical light from NASAs Hubble Space Telescope. Credit: X-ray: NASA/CXC/SAO/ R. DiStefano, et al.; Optical: NASA/ESA/STScI/ Grendler.
” We are trying to open up an entire brand-new arena for finding other worlds by searching for world candidates at X-ray wavelengths, a technique that makes it possible to find them in other galaxies,” stated Rosanne Di Stefano of the Center for Astrophysics|Harvard & & Smithsonian (CfA) in Cambridge, Massachusetts, who led the study, which was released on October 25, 2021, in Nature Astronomy.
This new result is based upon transits, events in which the passage of a planet in front of a star blocks a few of the stars light and produces a characteristic dip. Astronomers using both ground-based and space-based telescopes– like those on NASAs Kepler and TESS missions– have actually looked for dips in optical light, electro-magnetic radiation human beings can see, enabling the discovery of countless planets.
A composite image of M51 with X-rays from Chandra and optical light from NASAs Hubble Space Telescope includes a box that marks the place of the possible planet prospect. Credit: X-ray: NASA/CXC/SAO/ R. DiStefano, et al.; Optical: NASA/ESA/STScI/ Grendler.
Di Stefano and colleagues have instead searched for dips in the brightness of X-rays received from X-ray bright binaries. These luminescent systems typically contain a neutron star or black hole drawing in gas from a closely orbiting buddy star. The product near the neutron star or great void ends up being superheated and glows in X-rays.
Due to the fact that the region producing intense X-rays is small, a planet passing in front of it might obstruct most or all of the X-rays, making the transit simpler to find since the X-rays can completely disappear. This could allow exoplanets to be detected at much greater ranges than current optical light transit studies, which should be able to spot tiny reductions in light due to the fact that the world just blocks a small fraction of the star.
This binary system contains a black hole or neutron star orbiting a companion star with a mass about 20 times that of the Sun. Based on this and other info, the researchers estimate the exoplanet prospect in M51-ULS-1 would be approximately the size of Saturn, and orbit the neutron star or black hole at about two times the distance of Saturn from the Sun.
While this is a tantalizing study, more data would be needed to verify the interpretation as an extragalactic exoplanet. One difficulty is that the world prospects big orbit means it would not cross in front of its binary partner once again for about 70 years, warding off any efforts for a validating observation for years.
” Unfortunately to validate that were seeing a planet we would likely need to wait years to see another transit,” said co-author Nia Imara of the University of California at Santa Cruz. “And due to the fact that of the uncertainties about how long it requires to orbit, we would not understand precisely when to look.”.
Possible orbits. Credit: NASA/CXC/M. Weiss.
Can the dimming have been triggered by a cloud of gas and dust death in front of the X-ray source? The scientists consider this to be a not likely explanation, as the qualities of the event observed in M51-ULS-1 are not consistent with the passage of such a cloud. The design of a world prospect is, however, constant with the data.
” We know we are making a exciting and strong claim so we expect that other astronomers will take a look at it extremely thoroughly,” stated co-author Julia Berndtsson of Princeton University in New Jersey. “We think we have a strong argument, and this procedure is how science works.”.
This artists animation depicts the possible detection of a world prospect in a double system in the M51 (” Whirlpool”) galaxy. The view starts beyond the galaxy and after that travels into the star cluster including the double star called M51-ULS. This consists of either a neutron star or a black hole in orbit with a star about 20 to 30 times the mass of the Sun (big blue star). The neutron star or black hole is pulling product from its buddy star, developing a disk of material that shines in X-rays (red, orange, and yellow). Credit: NASA/CXC/A. Hobart.
An exoplanet in the system would have had to make it through a supernova surge that developed the neutron star or black hole. At some point the buddy star could likewise blow up as a supernova and blast the world when again with extremely high levels of radiation.
Di Stefano and her coworkers searched for X-ray transits in 3 galaxies beyond the Milky Way galaxy, utilizing both Chandra and the European Space Agencys XMM-Newton. Their search covered 55 systems in M51, 64 systems in Messier 101 (the “Pinwheel” galaxy), and 119 systems in Messier 104 (the “Sombrero” galaxy), leading to the single exoplanet prospect explained here.
This system includes either a neutron star or a black hole in orbit with a star about 20 to 30 times the mass of the Sun (large blue star). The neutron star or black hole is pulling material from its companion star, producing a disk of product that shines in X-rays (red, orange, and yellow).
The authors will browse the archives of both Chandra and XMM-Newton for more exoplanet prospects in other galaxies. Considerable Chandra datasets are offered for at least 20 galaxies, consisting of some like M31 and M33 that are much closer than M51, permitting much shorter transits to be detectable. Another interesting line of research is to look for X-ray transits in Milky Way X-ray sources to discover new close-by planets in unusual environments.
For more on this discovery, read First Evidence for a Possible Planet Outside of the Milky Way Galaxy.
Recommendation: “A possible planet candidate in an external galaxy spotted through X-ray transit” by Rosanne Di Stefano, Julia Berndtsson, Ryan Urquhart, Roberto Soria, Vinay L. Kashyap, Theron W. Carmichael and Nia Imara, 25 October 2021, Nature Astronomy.DOI: 10.1038/ s41550-021-01495-wPDF.
The other authors of this Nature Astronomy paper are Ryan Urquhart (Michigan State University), Roberto Soria (University of the Chinese Science Academy), Vinay Kashap (CfA), and Theron Carmichael (CfA). NASAs Marshall Space Flight Center handles the Chandra program. The Smithsonian Astrophysical Observatorys Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.
Astronomers have actually found evidence for a possible world prospect in the M51 (” Whirlpool”) galaxy, representing what might be the first planet detected beyond the Milky Way. Chandra identified the short-term dimming of X-rays from a system where an enormous star remains in orbit around a neutron star or great void (displayed in the artists illustration). This dimming is interpreted as being a planet that passed in front of an X-ray source around the neutron star or black hole. Credit: NASA/CXC/M. Weiss
Previously, astronomers have actually discovered all other recognized exoplanets and exoplanet candidates in the Milky Way galaxy, nearly all less than about 3,000 light-years from Earth.
Indications of a planet transiting a star outside of the Milky Way galaxy might have been spotted for the very first time. This appealing result, using NASAs Chandra X-ray Observatory, opens a new window to look for exoplanets at higher ranges than ever before.
The possible exoplanet candidate lies in the spiral nebula Messier 51 (M51), also called the Whirlpool Galaxy due to the fact that of its distinctive profile.
