Astronomers Might Have Found a Planet in Another Galaxy – Universe Today
[ad_1]
Not that long ago,, astronomers weren’t sure that exoplanets even existed. Now we know that there are thousands of them and that most stars probably harbour exoplanets. There could be hundreds of billions of exoplanets in the Milky Way, by some estimates. So there’s no reason to think that stars in other galaxies don’t host planets.
But to find one of those planets in another galaxy? That is a significant scientific achievement.
Astronomers find most exoplanets in our galaxy with the transit method. When a planet passes between us and its star, the star’s light dips a tiny amount as the planet blocks out some of the light. Measuring that slight dip is very difficult, but that’s what planet-hunters like NASA’s Transiting Exoplanet Survey Satellite (TESS) do. That method won’t work in another galaxy. It’s difficult to even discern individual stars in other galaxies, let alone detect the minuscule light blockage when a potential exoplanet transits in front of its star.
But TESS observes in visible light and near-ultraviolet light. What if observing a different part of the spectrum allowed astronomers to see individual stars in another galaxy and even planets orbiting those stars?
A team of astronomers have used data from the ESA’s XMM-Newton spacecraft, which observes x-rays, to discern individual stars in another galaxy. There are fewer bright objects in x-rays than in visible light, so identifying the sources of x-rays isn’t as challenging as in visible light.
The team has published a paper in the journal Nature Astronomy titled “A possible planet candidate in an external galaxy detected through X-ray transit.” The lead author is Rosanne Di Stefano from the Center for Astrophysics, Harvard & Smithsonian. In their paper, the researchers present evidence of a Saturn-sized planet orbiting a star in the Whirlpool Galaxy.
The team studied a particular type of star that shines brightly in x-rays. They’re called x-ray binaries because they exist in pairs, and their unique relationship makes them extremely x-ray emissive. An x-ray binary (XRB) consists of a donor star and an accretor. The donor star is usually a fairly typical star, and the accretor is either a stellar-mass black hole or a neutron star.
In an x-ray binary, the more massive accretor draws matter away from the donor star. As that matter falls into the donor, an enormous amount of gravitational potential energy is released and heats the material to millions of degrees. The heated material emits x-rays, and these x-rays are detectable by XMM-Newton.
If a large enough object passes between the x-ray binary and us, we could potentially observe a dip in x-rays, the same way TESS observes dips in visible light.
“X-ray binaries may be ideal places to search for planets because, although they are a million times brighter than our Sun, the X-rays come from a very small region. In fact, the source that we studied is smaller than Jupiter, so a transiting planet could completely block the light from the X-ray binary,” explains first author Rosanne Di Stefano in a press release.
Along with data from XMM-Newton, the team used data from NASA’s Chandra X-ray Observatory. Altogether they examined x-ray data from three galaxies for x-ray transits that might indicate the presence of planets. In the Whirlpool Galaxy, they found a transit that completely blocked the x-ray source for a few hours.
When astronomers detect something novel like this, they have to rule out other explanations before concluding it’s an actual planet. X-ray sources can be variable. There are flares and high and low emission states that can last for long periods of time. X-ray sources like M51-ULS-1 can even undergo x-ray off periods, where no there are no x-ray emissions. The team observed one of those periods, but it was observed separately from a transit.
It could have been an object other than a planet, like a brown dwarf or a red dwarf. But the system is too young for those explanations. And the transiting object was too large.
Changes in the density of the gas and dust in the system could have caused it.But the transiting object has a well-defined surface, which a cloud does not have. Even if the planet is a gas giant or a world with an extensive atmosphere, it still would have a well-defined surface. But the researchers make it clear that they can’t completely rule out a gas cloud. “We note, however, that the characteristics of clouds are so broad that the set of possibilities can never be completely explored and ruled out,” they explain.
There are also accretion dips. But dips are different than transits and can take different shapes, while transits do not. “Dips can differ in shape from the eclipses, and in fact, exhibit a wide range of shapes, even in the light curve of a single source. The most obvious difference between a dip and an eclipse is, however, that dips display energy dependence,” the paper states. The paper also explains that a dip changes the spectral nature of the x-ray signal, which provides “…information about the source and the material in its close environment.”
Another possible explanation is changes in the x-rays coming from the accretor itself. But the team eliminated that possibility because the temperature and the light colours never changed. The light was blocked for several hours, but other than that, it was unchanged.
“We first had to make sure that the signal was not caused by anything else,” says Di Stefano. “We did this by an in-depth analysis of the X-ray dip in the Chandra data, analyzing other dips and signals in the XMM data, and also modelling dips caused by other possible events, including a planet.”
They also considered that the donor star itself might be passing in front of the accretor. That did happen, according to the data from XMM-Newton. But that was separate from the other transit. The donor star transit caused a much more prolonged blackout.
In their paper, the authors wrote, “Instead, the data are well fit by a planet transit model in which the eclipser is most likely to be the size of Saturn.”
“We did computer simulations to see whether the dip has the characteristics of a planet transiting, and we find that it fits perfectly. We are pretty confident that this is not anything else and that we have found our first planet candidate outside of the Milky Way,” said Di Stefano.
So if there is a planet there, what are its properties? That’s difficult to say with certainty, but the team of researchers was willing to speculate from their data.
It’s about the size of Saturn, and it orbits the binary star at a great distance: it’s tens of times more distant from the binary than the Earth is from the Sun. It also takes about 70 years to complete one orbit. As for habitability? No way. The binary star bombards the planet with extreme amounts of radiation.
The 70-year orbit is a limitation of this study. The long orbital period means the data only showed one transit. That’s why the team is careful to call their finding a “planet candidate.” There’s no way to confirm it any time soon by observing more transits. They’ve eliminated the other possible causes, but other researchers may find something else in the data. “We can only say with confidence that it doesn’t fit any of our other explanations,” Di Stefano says.
This isn’t the first candidate planet in another galaxy. Other candidate planets have been found using gravitational lensing. In fact, one planet candidate was found in the Andromeda galaxy. But lensing events are random and don’t repeat, so there’s no way to confirm it like astronomers can with transits, which occur with each orbit of a planet.
There’s already one confirmed extra-galactic planet, and it was also found with x-rays. Astronomers found it in 1992 around the pulsar PSR1257 + 12. In fact, there are two or more planets orbiting that pulsar, according to researchers.
“The first confirmed planet outside of our Solar System was found around a pulsar, an object typically observed in X-rays. I am excited that X-rays now also play important step in the search for planets beyond the border of our galaxy,” said Norbert Schartel, XMM-Newton Project Scientist for ESA.
Are we seeing a new method of finding extragalactic planets coming to fruition?
“This work demonstrates a new method with the potential to discover planets in a wide range of systems hosting XRSs (X-Ray Sources). Because the most luminous XRSs can be detected in external galaxies, the search for extroplanets, planets in orbits located outside the Milky Way, has now become a realistic and practical enterprise,” the authors write in their paper.
“Now that we have this new method for finding possible planet candidates in other galaxies, our hope is that by looking at all the available X-ray data in the archives, we find many more of those. In the future we might even be able to confirm their existence,” said Di Stefano.
More:
[ad_2]
Original Post
Hi my friend! I wish to say that this post is awesome, nice written and include approximately all important infos. I would like to see more posts like this.
You really make it appear so easy together with your presentation however I in finding this matter to be actually something that I believe I would never understand. It kind of feels too complex and very huge for me. I’m looking ahead in your next put up, I’ll attempt to get the cling of it!
Everything is very open and very clear explanation of issues. was truly information. Your website is very useful. Thanks for sharing.
you are truly a excellent webmaster. The website loading velocity is incredible. It seems that you’re doing any distinctive trick. Moreover, The contents are masterpiece. you’ve done a magnificent process in this matter!
Some genuinely fantastic information, Gladiolus I observed this. “I know God will not give me anything I can’t handle. I just wish that He didn’t trust me so much.” by Mother Theresa.
I really wanted to make a brief message in order to appreciate you for the superb guides you are posting on this website. My incredibly long internet investigation has at the end been compensated with excellent ideas to go over with my contacts. I ‘d point out that we readers are very fortunate to exist in a magnificent site with so many awesome professionals with interesting guidelines. I feel very lucky to have come across your entire website and look forward to tons of more excellent minutes reading here. Thanks a lot again for all the details.
Awsome article and straight to the point. I am not sure if this is truly the best place to ask but do you guys have any thoughts on where to employ some professional writers? Thanks in advance 🙂
I cherished as much as you will obtain carried out right here. The caricature is tasteful, your authored material stylish. nevertheless, you command get got an impatience over that you wish be delivering the following. ill for sure come more previously once more since precisely the similar just about a lot often inside of case you defend this hike.
Hi my friend! I wish to say that this post is awesome, great written and come with almost all important infos. I’d like to see extra posts like this.
I would like to show my thanks to this writer for rescuing me from this type of dilemma. Just after scouting throughout the world-wide-web and coming across thoughts which are not productive, I was thinking my entire life was done. Being alive devoid of the approaches to the issues you’ve resolved all through your good guide is a crucial case, as well as those which may have in a wrong way affected my career if I hadn’t noticed your website. The natural talent and kindness in dealing with all the pieces was important. I am not sure what I would’ve done if I hadn’t discovered such a thing like this. I’m able to at this time look forward to my future. Thanks so much for your skilled and effective help. I won’t hesitate to endorse your web page to any individual who should receive guide on this subject matter.
I really like your writing style, fantastic information, thanks for putting up :D. “Let every man mind his own business.” by Miguel de Cervantes.
hey there and thank you for your information – I have certainly picked up anything new from right here. I did however expertise a few technical points using this website, as I experienced to reload the website a lot of times previous to I could get it to load properly. I had been wondering if your hosting is OK? Not that I am complaining, but slow loading instances times will sometimes affect your placement in google and could damage your high quality score if advertising and marketing with Adwords. Anyway I’m adding this RSS to my e-mail and can look out for a lot more of your respective intriguing content. Make sure you update this again soon..
I went over this web site and I conceive you have a lot of superb info , bookmarked (:.
Some really rattling work on behalf of the owner of this web site, perfectly great articles.
You are my breathing in, I possess few blogs and sometimes run out from post :). “‘Tis the most tender part of love, each other to forgive.” by John Sheffield.
I have not checked in here for a while as I thought it was getting boring, but the last several posts are good quality so I guess I’ll add you back to my daily bloglist. You deserve it my friend 🙂
Thanks for another informative web site. Where else could I get that kind of info written in such an ideal way? I’ve a project that I’m just now working on, and I have been on the look out for such information.
Its like you read my mind! You appear to know so much about this, like you wrote the book in it or something. I think that you can do with a few pics to drive the message home a bit, but other than that, this is wonderful blog. An excellent read. I’ll definitely be back.
I like forgathering utile information , this post has got me even more info! .
I’d have to examine with you here. Which is not one thing I usually do! I take pleasure in reading a post that may make folks think. Additionally, thanks for permitting me to comment!
Great paintings! This is the type of info that are supposed to be shared around the net. Disgrace on the search engines for not positioning this publish higher! Come on over and seek advice from my web site . Thank you =)
I truly appreciate this post. I’ve been looking all over for this! Thank goodness I found it on Bing. You have made my day! Thank you again
Awesome blog! Do you have any tips and hints for aspiring writers? I’m planning to start my own website soon but I’m a little lost on everything. Would you advise starting with a free platform like WordPress or go for a paid option? There are so many choices out there that I’m completely confused .. Any suggestions? Bless you!
I’ve been surfing online more than 3 hours today, yet I never found any interesting article like yours. It’s pretty worth enough for me. In my view, if all web owners and bloggers made good content as you did, the net will be much more useful than ever before.
Excellent weblog right here! Additionally your site a lot up very fast! What web host are you using? Can I am getting your affiliate hyperlink for your host? I desire my website loaded up as fast as yours lol
I’m not that much of a online reader to be honest but your blogs really nice, keep it up! I’ll go ahead and bookmark your site to come back in the future. All the best
Thank you for every other informative site. Where else could I am getting that kind of information written in such an ideal manner? I’ve a challenge that I am simply now running on, and I have been at the look out for such info.
Right now it seems like Movable Type is the best blogging platform available right now. (from what I’ve read) Is that what you’re using on your blog?
Howdy! This is my 1st comment here so I just wanted to give a quick shout out and say I really enjoy reading through your articles. Can you suggest any other blogs/websites/forums that deal with the same topics? Thanks a lot!
Would love to constantly get updated great site! .
I know this if off topic but I’m looking into starting my own blog and was curious what all is required to get setup? I’m assuming having a blog like yours would cost a pretty penny? I’m not very internet smart so I’m not 100 positive. Any tips or advice would be greatly appreciated. Appreciate it
I?¦m now not positive where you are getting your information, but great topic. I must spend some time studying much more or understanding more. Thanks for fantastic information I used to be on the lookout for this information for my mission.
What is Boostaro? Boostaro revolutionizes romantic performance enhancement through its reliance on the wisdom of natural ingredients
Yeah bookmaking this wasn’t a high risk determination great post! .
An impressive share, I just given this onto a colleague who was doing a little analysis on this. And he in fact bought me breakfast because I found it for him.. smile. So let me reword that: Thnx for the treat! But yeah Thnkx for spending the time to discuss this, I feel strongly about it and love reading more on this topic. If possible, as you become expertise, would you mind updating your blog with more details? It is highly helpful for me. Big thumb up for this blog post!
I loved as much as you will receive carried out right here. The sketch is tasteful, your authored subject matter stylish. nonetheless, you command get got an shakiness over that you wish be delivering the following. unwell unquestionably come further formerly again since exactly the same nearly a lot often inside case you shield this hike.
I’ll right away clutch your rss as I can’t find your e-mail subscription hyperlink or newsletter service. Do you’ve any? Kindly permit me understand so that I may just subscribe. Thanks.
You can certainly see your skills in the paintings you write. The arena hopes for more passionate writers like you who are not afraid to mention how they believe. At all times go after your heart.
Hiya, I am really glad I’ve found this information. Nowadays bloggers publish just about gossips and web and this is really annoying. A good web site with interesting content, that is what I need. Thanks for keeping this web site, I will be visiting it. Do you do newsletters? Can’t find it.
Good post. I be taught one thing tougher on completely different blogs everyday. It will at all times be stimulating to learn content from different writers and observe a bit one thing from their store. I’d favor to use some with the content on my blog whether you don’t mind. Natually I’ll give you a hyperlink on your internet blog. Thanks for sharing.
you’re actually a good webmaster. The website loading pace is incredible. It sort of feels that you’re doing any distinctive trick. In addition, The contents are masterpiece. you have done a fantastic activity on this subject!