Signs of first planet found outside our galaxy
Astronomers have found hints of what could be the first planet ever to be discovered outside our galaxy. Nearly 5,000 "exoplanets" - worlds orbiting stars beyond our Sun - have been found so far, but all of these have been located within the Milky Way galaxy.
The possible planet signal discovered by Nasa's Chandra X-Ray Telescope is in the Messier 51 galaxy. This is located some 28 million light-years away from the Milky Way.
[...] Dr Rosanne Di Stefano and colleagues searched for dips in the brightness of X-rays received from a type of object known as an X-ray bright binary. These objects typically contain a neutron star or black hole pulling in gas from a closely orbiting companion star. The material near the neutron star or black hole becomes superheated and glows at X-ray wavelengths. Because the region producing bright X-rays is small, a planet passing in front of it could block most or all of the X-rays, making the transit easier to spot.
The team members used this technique to detect the exoplanet candidate in a binary system called M51-ULS-1.
[...] The transit lasted about three hours, during which the X-ray emission decreased to zero. Based on this and other information, the astronomers estimate that the candidate planet would be around the size of Saturn, and orbit the neutron star or black hole at about twice the distance Saturn lies from the Sun.
Also at NASA.
A possible planet candidate in an external galaxy detected through X-ray transit
Previously: Detection of Extragalactic Exoplanets and Large Organic Molecules
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Astronomers have detected exoplanets in a galaxy 3.8 billion light years away using gravitational microlensing:
In an incredible world first, astrophysicists have detected multiple planets in another galaxy, ranging from masses as small as the Moon to ones as great as Jupiter. Given how difficult it is to find exoplanets even within our Milky Way galaxy, this is no mean feat. Researchers at the University of Oklahoma achieved this thanks to clever use of gravitational microlensing.
[...] Oklahoma University astronomers Xinyu Dai and Eduardo Guerras studied a quasar 6 billion light-years away called RX J1131-1231, one of the best gravitationally lensed quasars in the sky. The gravitational field of a galaxy 3.8 billion light-years away between us and the quasar bends light in such a way that it creates four images of the quasar, which is an active supermassive black hole that's extremely bright in X-ray, thanks to the intense heat of its accretion disc.
Using data from NASA's Chandra X-ray observatory, the researchers found that there were peculiar line energy shifts in the quasar's light that could only be explained by planets in the galaxy lensing the quasar. It turned out to be around 2,000 unbound planets with masses ranging between the Moon and Jupiter, between the galaxy's stars. "We are very excited about this discovery. This is the first time anyone has discovered planets outside our galaxy," Dai said.
Separately, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have detected dimethyl ether and methyl formate molecules in the Large Magellanic Cloud (LMC), a dwarf galaxy and satellite of the Milky Way just 160,000 light years away. These molecules had not been previously detected outside of the Milky Way galaxy. The study also found evidence of methanol, which had already been detected in the LMC.
Probing Planets in Extragalactic Galaxies Using Quasar Microlensing (DOI: 10.3847/2041-8213/aaa5fb) (DX)
The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud (DOI: 10.3847/2041-8213/aaa079) (DX)
Also at Universe Today, National Geographic, the University of Oklahoma, and the National Radio Astronomy Observatory.
(Score: 4, Informative) by StupendousMan on Tuesday October 26 2021, @01:03PM (6 children)
In order to confirm that a dip in brightness is produced by the transit of a planet, one must measure a series of transits at periodic intervals: two transits allows one to guess a period, and three transits will confirm (or reject) that period. The candidate in this case might be twice as far from its host star as Saturn is from the Sun. Saturn takes about 29 years to complete one orbit, so _if_ the host star has roughly the mass of the Sun, we might have to wait three decades for transit number 2, and then another 30 years for transit number 3. Even if the mass of the host star is several times that of the Sun, which would decrease the period, astronomers will still have to wait years to confirm this. Moreover, in order not to _miss_ a transit, they would have to monitor the source continuously for that entire time, which is .. not likely.
Bummer.
(Score: 2) by takyon on Tuesday October 26 2021, @01:38PM
It seems like they determined a lot about it already, like the orbital period from just the one transit.
Proxima Centauri is more interesting.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: -1, Troll) by Anonymous Coward on Tuesday October 26 2021, @01:47PM (2 children)
Common sense suggests that the jewels in the firmament are no more than 500 miles away, which is close enough that they can be reached by any vessel capable of navigating both the air and the waters above the firmament. Harvesting the jewels can provide a revenue stream for the 2nd incarnation of Musk to continue his mission.
(Score: 0) by Anonymous Coward on Tuesday October 26 2021, @02:29PM (1 child)
Dear God I hope this is satire, it is getting so hard to tell these days.
(Score: 0) by Anonymous Coward on Tuesday October 26 2021, @11:36PM
Crespo Dollar is a thing. Watch evangelicals on youtube and weep at the intellectual divide. Jewels in the firmament are a bedrock of Truth for most people.
(Score: 0) by Anonymous Coward on Tuesday October 26 2021, @06:47PM
The estimated orbital period is 70 years.
(Score: 1) by kreuzfeld on Tuesday October 26 2021, @10:14PM
First responder is correct. I was afraid we would see martyb post this article here... it's a shameful attempt by some astronomers who should know better to gain some free press attention. The odds are astronomically (ha) higher that this is anything but a planet; as someone who works in this field, it's embarrassing to see the claims being made about this so-called 'discovery.'