The oldest gamma-ray burst ever discovered was just a piece of space junk
[ad_1]
Sometimes a flash is just a fluke.
A signal that scientists first believed was the ground-breaking discovery of a gamma-ray burst from the oldest known galaxy in the universe was in fact a reflection of sunlight from a spent rocket stage in Earth’s orbit, a new paper has found.
The disappointing conclusion comes from a team of Polish scientists following a discussion involving several teams about the origin of the serendipitous sighting made by one of the twin Keck telescopes in Hawaii in 2017. Whereas previous contributions to the debate focused on the probability of seeing a satellite compared to an extremely rare gamma-ray burst, the Polish team managed to track down the exact object that caused the flash — a spent Breeze-M upper stage from a Russian Proton rocket.
“We checked our calculations against three other publicly available orbit calculation software,” Michal Michalowski, an astronomer at the Adam Mickiewicz University in Poland and lead author of the new study, told Space.com.
So what exactly did the Keck telescope see and how is it even possible to mistake the most powerful flash of light in the universe taking place billions of light-years away for sunlight reflecting off a piece of space junk?
Related: Astronomers catch fizzled-out gamma-ray burst from supernova
A chance sighting
The team behind the original observation, led by scientists from the University of Beijing in China, set out to study one of the oldest galaxies in the universe. Known as GN-z11, the galaxy is more than 13 billion light-years away from Earth. That means telescopes can only see it as it looked some 420 million years after the Big Bang, when the universe was very young.
The team used a near-infrared spectrograph called MOSFIRE mounted on one of the Keck telescopes. Instead of capturing images, the spectrograph measures the brightness of a celestial object at specific wavelengths of light. The team was taking three-minute measurements of GN-z11 when suddenly, the galaxy lit up. Within the next three minutes, however, the signal was back to normal.
After ruling out other possibilities, the scientists concluded that the sudden brightening must have been a gamma-ray burst, the brightest and most energetic flash of light in the universe believed to be produced by explosions of massive stars at the end of their lives, which astronomers call supernovas. Lasting only a few seconds, gamma-ray bursts briefly outshine everything else in the surrounding cosmos. But tracing their origins has so far been elusive.
The team published their findings in the journal Nature Astronomy last December. The discovery seemed like a big deal. Scientists have never observed a gamma-ray burst in such an old galaxy, and seeing one would reveal new information about the early universe.
Too elusive
However, other astronomers soon started to question the findings, and two papers published Monday (Oct. 4) in the journal Nature Astronomy lay out what went wrong.
In one, Charles Steinhardt, associate professor of astronomy at the University of Copenhagen in Denmark, and his colleagues argued that the brightening was likely caused by an object orbiting Earth rather than a chance sighting of a rare gamma-ray burst. The reason: probability.
“The probability of catching a gamma-ray burst like this is incredibly low, something like 1 in 10 billion,” Steinhardt told Space.com.
Astronomers estimate that although satellites spot about one gamma-ray burst per day, roughly 500 are occurring within the same time period. However, in most cases, scientists have no idea no idea which galaxies these bursts came from.
“The big gamma-ray telescopes that we use to detect gamma-rays only tell you that a burst went off and give you the rough region of the sky where that happened,” Steinhardt said. “If you want to know the exact galaxy, you would have to point an optical telescope at that region quickly enough to catch the flash and find its source. But you only have a maximum of 100 seconds to do that.”
The odds
To catch a gamma-ray burst in the oldest known galaxy during a random imaging campaign seemed a bit too lucky. Steinhardt and his colleagues therefore looked for other explanations, including reconsidering those ruled out by the Chinese team. The scientists trawled the MOSFIRE archives and found dozens of similar occurrences in other observations.
“When we looked at the signal of the brightening, it actually didn’t look like any of the 10,000 gamma-ray bursts detected before,” Steinhardt said. “It looked more like a typical star, for example our sun. So that might include everything that reflects sunlight.”
In the original paper, the Chinese team claimed a reflection from a satellite couldn’t have caused the brightening. The scientists wrote that they checked against available orbital information of known satellites and pieces of debris and didn’t find an object whose trajectory would have matched the sighting. The astronomers also wrote that it would be extremely unlikely for a satellite or a piece of debris to interfere with observations like that. But the results of Steinhardt and his colleagues give a more favorable probability for such an incident to occur — about one in 1,000.
“If you have a probability of catching a satellite like this one in a 1,000 versus a one in a billion probability of catching a gamma-ray burst, it is clearly 1 million times more likely that you have caught a satellite,” Steinhardt said.
Images from optical telescopes streaked with trails of orbiting satellites have been in the spotlight recently as astronomers call for restrictions on satellite megaconstellations such as SpaceX‘s Starlink internet-beaming project. The smears are obvious and their source unmistakable. In case of spectroscopic measurements, however, picking out the noise is much more challenging.
Tracking down the culprit
“It’s very difficult to distinguish that in spectroscopy,” Michalowski said. “The spectrograph takes in the light through a very narrow slit. The satellite is outside of the slit and then it is suddenly inside of it for a very short moment, there is no trail leading up to it.”
Michalowski and his team, spurred by Steinhardt’s estimates, tracked down the actual source of the brightening by searching the publicly available Space-Track database of orbiting objects. The Breeze-M upper stage circling Earth in a highly elliptical orbit was exactly at the right place at the right time, Michalowski said
Interestingly, the Chinese team had originally excluded this rocket stage based on calculations using the web-based astronomical calculator called Calsky. But Michalowski is confident that their calculations were wrong.
“It’s hard to say why the original calculation differed,” he said. “The software that the team used is now down so it’s impossible to reproduce that. Our calculations match four others so we are fairly confident that we got it right.”
A growing problem in astronomy
The conundrum highlights a growing problem in astronomy: the increasing number of satellites and space debris objects in orbit interferes with astronomical observations and the exploration of the universe. A recent study estimated that up to 40% of astronomical observations with wide-field telescopes could be ruined after SpaceX deploys all of the currently planned 12,000 satellites of its Starlink constellation.
The solution, according to Michalowski, is not easy. “There are countless examples even now where satellites cross images, and it will only get worse,” Michalowski said. “The only solution is to observe these satellites and determine their orbits more accurately so that we create a very precise catalogue that will help tell us whether something was actually an astronomical event or a passing satellite.”
Steinhardt agreed. “If we had a good database, if we knew that a satellite or a piece of debris was going to pass through that part of the sky in that particular second, we would have stopped the observations for that second, waited for it to pass by, and then started the next exposure,” he said. “The reason that didn’t happen is that right now, we don’t have the right database or the right toolkit.”
Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.
[ad_2]
Original Post
I really like your writing style, good info, thanks for putting up :D. “In university they don’t tell you that the greater part of the law is learning to tolerate fools.” by Doris Lessing.
Im now not certain the place you’re getting your information, but good topic. I must spend a while learning more or working out more. Thanks for magnificent information I was looking for this info for my mission.
I gotta favorite this site it seems invaluable very helpful
Hey would you mind stating which blog platform you’re using? I’m going to start my own blog soon but I’m having a hard time deciding between BlogEngine/Wordpress/B2evolution and Drupal. The reason I ask is because your design and style seems different then most blogs and I’m looking for something completely unique. P.S Apologies for being off-topic but I had to ask!
You made some clear points there. I did a search on the subject matter and found most guys will approve with your website.
Awsome article and right to the point. I am not sure if this is truly the best place to ask but do you folks have any ideea where to get some professional writers? Thanks in advance 🙂
Very efficiently written information. It will be beneficial to anybody who utilizes it, including myself. Keep up the good work – can’r wait to read more posts.
I am not certain where you’re getting your info, but great topic. I must spend some time studying more or working out more. Thank you for great information I used to be in search of this information for my mission.
Hiya, I’m really glad I’ve found this info. Today bloggers publish only about gossips and web and this is actually irritating. A good blog with interesting content, that is what I need. Thank you for keeping this web site, I will be visiting it. Do you do newsletters? Can’t find it.
Utterly written subject material, Really enjoyed looking at.
I used to be recommended this blog by my cousin. I am now not positive whether or not this publish is written through him as nobody else recognise such detailed about my difficulty. You’re wonderful! Thank you!
I’d should examine with you here. Which is not something I usually do! I enjoy reading a put up that can make individuals think. Additionally, thanks for permitting me to remark!
Thank you for any other informative blog. Where else could I get that type of information written in such a perfect manner? I have a challenge that I’m just now running on, and I have been at the glance out for such info.
I see something genuinely interesting about your web site so I saved to fav.
Hi my loved one! I want to say that this post is amazing, nice written and come with approximately all vital infos. I would like to see extra posts like this .
Hey would you mind letting me know which hosting company you’re utilizing? I’ve loaded your blog in 3 completely different browsers and I must say this blog loads a lot quicker then most. Can you recommend a good hosting provider at a honest price? Cheers, I appreciate it!
I’m impressed, I must say. Really not often do I encounter a weblog that’s each educative and entertaining, and let me inform you, you could have hit the nail on the head. Your thought is excellent; the problem is one thing that not sufficient people are speaking intelligently about. I am very completely satisfied that I stumbled throughout this in my search for one thing relating to this.
Hello this is kinda of off topic but I was wanting to know if blogs use WYSIWYG editors or if you have to manually code with HTML. I’m starting a blog soon but have no coding knowledge so I wanted to get advice from someone with experience. Any help would be greatly appreciated!
This really answered my problem, thank you!
Greetings! This is my first comment here so I just wanted to give a quick shout out and tell you I really enjoy reading through your blog posts. Can you recommend any other blogs/websites/forums that deal with the same topics? Thanks!
When I originally commented I clicked the -Notify me when new comments are added- checkbox and now each time a comment is added I get four emails with the same comment. Is there any way you can remove me from that service? Thanks!
Hiya! I simply would like to give a huge thumbs up for the great info you’ve got here on this post. I will probably be coming again to your weblog for extra soon.
It’s appropriate time to make some plans for the future and it is time to be happy. I’ve read this post and if I could I want to suggest you few interesting things or tips. Maybe you could write next articles referring to this article. I desire to read more things about it!
I would like to thank you for the efforts you have put in writing this web site. I am hoping the same high-grade blog post from you in the upcoming also. Actually your creative writing abilities has inspired me to get my own site now. Actually the blogging is spreading its wings quickly. Your write up is a great example of it.
Nice post. I learn one thing more difficult on totally different blogs everyday. It’ll at all times be stimulating to learn content material from other writers and practice slightly something from their store. I’d desire to make use of some with the content on my blog whether you don’t mind. Natually I’ll offer you a hyperlink in your internet blog. Thanks for sharing.
I’m just commenting to let you understand what a superb discovery my friend’s girl undergone checking yuor web blog. She even learned lots of pieces, not to mention what it’s like to possess a great coaching style to let a number of people without problems master certain hard to do issues. You actually surpassed visitors’ expected results. Many thanks for supplying such practical, trustworthy, informative and fun tips about the topic to Jane.
Its excellent as your other articles : D, appreciate it for putting up.
Hey just wanted to give you a quick heads up. The text in your content seem to be running off the screen in Ie. I’m not sure if this is a formatting issue or something to do with internet browser compatibility but I figured I’d post to let you know. The style and design look great though! Hope you get the issue fixed soon. Many thanks
Excellent post. I was checking constantly this blog and I am impressed! Extremely helpful information specifically the last part 🙂 I care for such information a lot. I was seeking this particular information for a very long time. Thank you and good luck.
Thankyou for all your efforts that you have put in this. very interesting information.
Good V I should certainly pronounce, impressed with your website. I had no trouble navigating through all the tabs as well as related information ended up being truly simple to do to access. I recently found what I hoped for before you know it at all. Quite unusual. Is likely to appreciate it for those who add forums or something, site theme . a tones way for your client to communicate. Nice task..
Hi there just wanted to give you a quick heads up. The text in your content seem to be running off the screen in Opera. I’m not sure if this is a formatting issue or something to do with internet browser compatibility but I thought I’d post to let you know. The design look great though! Hope you get the problem fixed soon. Many thanks
Wow! Thank you! I continuously needed to write on my site something like that. Can I include a part of your post to my website?