Its observations like these that really give us an idea about how big the cosmos actually is. A star in a small galaxy called the Large Magellanic Cloud (LMC), some 160,000 light years from Earth, exploded as a massive supernova 400 years ago (Earth years that is). Combining the observations from an X-ray observatory and an optical telescope, scientists are currently observing the reflected light off galactic dust, only just reaching the Earth hundreds of years after the explosion…
Shakespeare’s first run the stage production, Hamlet, will have been in full-swing. Galileo might have been experimenting with his first telescope. Guy Fawkes could have been plotting to blow up the British parliament. These events all occurred around the beginning of the 17th Century when a bright point of light may have been seen in the night sky. This point of light, in the Large Magellanic Cloud (LMC), is a massive star exploding, ending its life in a powerful supernova.
Now, 400 years after the event, we can see a “supernova remnant” (SNR), and this particular remnant is known as SNR 0509-67.5 (not very romantic I know). The remnant of superheated gas slowly expands into space and still emits X-rays of various energies. The 400 year old explosion has even been imaged in great detail by the Chandra Observatory currently observing space in X-ray wavelengths. Analysis of the SNR indicates that it was most likely caused by a Type Ia supernova after analysis of the composition of the gases, in particular the quantities of silicon and iron, was carried out. It is understood that the supernova was caused when a white dwarf star in a binary system reached critical mass, became gravitationally unstable (due to fusion reactions in the core stopping) and exploded.
When SNR 0509-67.5 exploded all those years ago, it will have radiated optical electromagnetic radiation (optical light) in all directions of space. Now, for the first time, optical Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory (Chile) has observed reflected light from within the LMC originating from the supernova, 400 years after the event. Using the (reflected) optical light and X-ray emissions directly from the supernova remnant, scientists have been able to learn just how much energy was generated by the explosion.
Astronomers have even assembled a time-lapse video from observations of the light “echo” from 2001 to 2006. Although there are only five frames to the video, you can see the location of the reflected light change shape as different volumes of galactic dust are illuminated by the flash of supernova light. In each progressive frame, the clouds of gas that become illuminated will be further and further away from us, we are effectively looking further back in time as the light “echoes” bounce off the galactic matter.
An amazing discovery.
Source: Chandra X-ray Observatory
So how does light from a Supernova 160,000 light years away reach us in just 400 years?
My thoughts exactly. I think the author needs to check his math. If the galaxy is 160,000 light years away and the event was first seen 400 years ago then wouldn’t it have happened 160,400 years ago?
The supernova exploded 160,400 years ago. And now we are seeing the light from the superheated gas that glowed 160,000 years ago; 400 years after the supernova exploded. No need for the author to check his math.
On a lighter note (pun), since we recently observed an event more than halfway across the universe, maybe we’ll one day see beyond the “other side of the universe” – and view into our own future to witness Andromeda colliding with our galaxy. Talk about theoretical…..;)
Exactly. Note “Earth years”
Laszlo Says:
March 23rd, 2008 at 4:50 pm
Doug Says:
March 23rd, 2008 at 5:09 pm
These are common mis-perceptions when discussing timing of astronomical events. Typically when we discuss a random astronomical event specifically in terms of observations, we talk about it happening at the time when we observed it here on Earth. Hence, we say things like ‘that supernova exploded 400 years ago’ if it were observed in the year 1608, or we name a supernova 1987a if we saw it in 1987. We do this even if the event actually occurred very far away (and hence long ago), for example 160,000 light years away. It is sort of taken as a given that ‘this event occurred 400 years ago’ means 400 years ago plus the time the light took to get here to observe it. It would be better to say ‘blah event was observed 400 years ago’ rather than ‘blah event happened 400 years ago’, but its not too hard to interpret once you get the hang of it…
On the other hand, often when discussing events in a more theoretical manner or in terms of a broader theory, astronomers and physicists will talk about the time something happened in the more absolute sense – e.g. – the sentence ‘in the standard Big Bang model, the reionisation era occurred roughly 12.3 billion years ago’ obviously doesn’t mean that reionisation was observed 12.3 billion years ago on Earth plus the time the light took to reach us. Rather, as it refers to something more intrinsic to the universe in a broader model, an absolute date is assigned to it rather than a relative one.
As a general guideline, anything referred to in an observational sense uses the more relative ‘when we saw it’ dating scheme, whereas things referred to in a more theoretical sense generally use the absolute ‘when it happened from the universe’s perspective’ scheme.
Although it can be a little fuzzy sometimes to work out which ‘scheme’ is being used when if you’re not familiar with it, it eventually becomes second nature to slip between the two cases without even consciously thinking about it too much, depending on the situation.
Also, just concerning an error in the article –
“It is understood that the supernova was caused when a white dwarf star in a binary system reached critical mass, became gravitationally unstable (due to fusion reactions in the core stopping) and exploded.”
Type 1a supernovae, it is thought, do indeed occur due to a white dwarf becoming unstable in a binary system, but the gravitational instability is not actually related to fusion ceasing in its core.
White dwarfs are the remnants of stars that have already finished fusing material at their core – they are small, extremely dense and hot. They maintain their shape against the force of gravity not from radiation pressure (like normal main sequence stars), of which there is not much due to core fusion having ceased, but due to the quantum mechanical effect of electron degeneracy. However, electron degeneracy can only withstand so much pressure, and when mass is inevitably transferred from the binary partner to the white dwarf and builds up on the surface, he process can finally support no more when the WD reaches a mass of about 1.4 Ms and it collapses as a type 1a supernova.
This minor error doesn’t, of course, in any way detract from the great article. Keep ’em coming!
Alright, does anybody know about our Galaxy colliding with the Adromeda Galaxy? i mean its only light years away,
Ian, great attempt at explaining some of the confusing timing of astronomical events to the layman. Showing that something actually happened 160,000 light years ago was first seen 400 years ago and is still unfolding before our eyes now 400 years later while we develop instruments that can finally observe it in “slow motion” is pretty cool. You could also compare the movie at “one frame per year” for a human to understand what was going on to our normal movies or TV at 16-24 frames per second or even 30 or 60 frames per second which is common for events in our life here on earth to see in motion.
“Shakespeare’s first run the stage production, Hamlet, will have been in full-swing. Galileo might have been experimenting with his first telescope. Guy Fawkes could have been plotting to blow up the British parliament. These events all occurred around the beginning of the 17th Century when a bright point of light may have been seen in the night sky”
Perhaps the author should know that the Large Magellanic Cloud (LMC) is visible from southern hemisphere.
@Sheperd
‘Only’ 2.5 Million Light Years, and it’s approaching at 300 km/s.
You do the math.
Essel, Galileo, Shakespeare, and Mr. Fawkes were all too busy to watch for bright specks in Galactic satellites. The Author wasn’t suggesting they could have seen the nova, just that they were around at the same time. Not too many famous Australians from that time.
See Ian o’Neil!
no need for sensationalism1
Good writing!
To expand a touch on electron degeneracy and why white dwarfs explode..Degenerate electrons cannot change energy levels as they can in atoms of ordinary matter. They do, however, vibrate but relativity forbids those vibrations from reaching speed c. When enough material has fallen onto the dwarf gravity will win the battle that the electrons have been resisting. Their resistance, due to their repulsion of getting too near one another, has been holding the star together. But once gravity wins the battle, fusion takes place all over and through the star as electrons crash right into the nuclei from such a close proximity. The number of neutrinos released are enormous and the probability for neutrino collisions with surrounding nuclei and matter skyrockets. They slam into everything in the vicinity and blow the star to smithereens.
Here I am, 68 years old now. [not even a split second in Geological time] My mind has always been involved in some way or another, regarding…. “The Universe”
But, it didn’t take me 68 years to become aware of “Infinity!” and studying everything I can find on the subject! Retired and having my computer, I have found endless [pardon the pun] sites to explore on the subject.
I find Infinity, to be the most important clue, to everything that exists or doesn’t. Where I start is…prior to the “Big Bang Theory”… what was there waiting for that Big Bang to take place!? There had to be something. There was, another area of Infinity!
By thinking about it this way, Infinity seems to be considered? I use Logic when possible. For example, Infinity cancels out two important factors, Time and Distance! You can’t go for ever, if you don’t have the time to do it! Both can be done.
I have submitted my ideas of Infinity to many articles that are covering the findings of the “Universe” in some manner. Regarding Time, I say, it can’t be anything but “Now.” And
Nobody responds?
Especially, when I combine Infinity with the black backdrop, [ for the lack of a better word] which allows us to see the stars in the night sky, known as “Black Matter” or “Dark Matter” in the Science World. I believe it’s the Color of Infinity, since, it has NO END! I may be laughed at, BUT…….Nobody Knows Any different!
If you venture into Deep Space, far enough to see our entire “Solar System, you will see No Evidence of Time! You will see places Dark on one side and Light on the other! WHAT?
g-man
PS: Nice article Bob.
I asked this a few years ago, and I ask again; Do we have enough resolution to map the galaxy as the wavefront of light passes through? Can we say that this cloud is here and that cloud is there and they are that big and shape? So what if it’s a long term project. We could learn more from the outside than we could from inside the Milky Way about many structural features, if we could do the map.
Oh yeah, the sky is full of stars. It’s hard to find an opening through them to see to the 14 billion L.Year limit. It looks black because our eyes can’t amplify the light enough to see the stars without help. Black is absence of light, not a curtain in the background.
Definitely the author had his astromical grammer worng . According to earth year the incident was viewed 400 years back .
(actual event occured before 160,000 light years ago with repect to distance to meganallic cloud) note currently scientists are currently observing the reflected light off galactic dust —
Still an article from a reputed site like Universe today must have it news more clear & accurate ..
‘Light Echos from 400 Year Old Supernova Observed for the First Time’ Oh Come on Mr. O’Neill, if you are going to write about something make sure you are right, echoes from Supernova have been written about for years, try ‘Sky and Telescope’ for January 1990 (pg22), there’s an indepth four page article with photographs of SN1987A and its light echo. and as for a 160,000 lt year object observed 400 lt years after going nova…
…oh by the way, it was not the ‘British Parliament’ but the English Parliament. The Scottish joined us when they lost money in Panama to create the following…
‘Following the Treaty of Union in 1707, Acts of Parliament passed in the Parliament of England and the Parliament of Scotland created a new Kingdom of Great Britain and dissolved both parliaments, replacing them with a new Parliament of Great Britain based in the former home of the English parliament. The Parliament of Great Britain would later become the Parliament of the United Kingdom in 1801 when the United Kingdom of Great Britain and Ireland was formed through the Act of Union 1800.’
See… Wikipedia
How interesting? The Express says’ers that followed my comment needs to get back to their Koolaid!
Clearly, I know that the Dark Sky at night is Not a Curtain backdrop! I also take issue with people who have Not found the proper definition of Time! And by not understanding
how Time plays a part in Human Minds.
For example, the only reason a Day of the week or Months of a year and so on, is because, We Humans, throughout the world…ALL AGREE to which one we are
referring to!
We prove this Two Times a Year! It’s called Daylight Savings! Hmmmm. In the spring, WE Push Time forward one Hour and of course in the fall, WE Pull Time Back an hour!? All else is hogwash!
This is evidence that clearly Supports my claim! So, WE, TOGETHER, can manipulate what we call time, as long as we All Agree to it, period!
With this Subject Matter I’m learning about, is not necessarily what WE have been conditioned for! Time Does Not Exist!
I defy anyone to prove different to this…”It Is Never> Not Now! No matter when you are disturbed to wake up in the middle of the night, Reality will remain to be, Today!!
Yesterday and Tomorrow are ONLY OUR THOUGHTS OF! In other words…Tomorrow will NEVER ARRIVE! Don’t you get it??
Mr. O’Neill, thank you for your article. I enjoyed it and I learned from it as well!
Respectfully,
the “G”
PS: Also, there has Never been a moment
Without Temperature!, to some degree!
Wow. Absolutely incredible
That is really cool stuff!!
I saw a TV show not too long ago that did a “progression” video with the Hubble UDF that let you slowly see the pic as if you were diving through and into the Hubble Ultra Deep Field.
It was INCREDIBLE!!! It really gave you the impact of traveling back in time!!
Does anyone know if that “video” is available online and where it can be found?