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Watch the Crab Nebula Expand Over a 13 Year Period
The Bad Astronomer writes "A thousand years ago, the light from the explosion of a massive star reached the Earth. We now call this supernova remnant the Crab Nebula, and a new image of the Crab taken by astronomer Adam Block shows the physical expansion of the debris, made obvious in a short video comparing his 2012 observations with some taken in 1999. The outward motion of filaments and knots in the material can be easily traced even over this relatively short time baseline."
LAME!!! just 2 exposures alternating back and forth.
Craaaaaaab people! Craaaaaaaab people! Craaaaaab people!
The newer one picks up more of the blue, so it looks larger. If you watch the red, it is definitely moving outward. Will have to use this the next time I teach about nebula.
The video was over a minute, watching two images flip back and forth every couple of seconds with cheesy music in the background.
No voice over, no explanation, no real utility to the video. Showing the two static snapshots in a super-imposable way would have been a cooler use of technology.
2.43759728 × 10^-9 FPS should be enough for anybody.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Can't wait for the next 13 year sequel, it will be a blast !
that gives we Ents a headache, please slow it down
Plus the biggest changes seem to be in the colors not the growth which might be related to the fact it was taken by two different telescopes....
Technology, the cause of and solution to all of life's problems.
The Crab Nebula exploded in 1054; well, 6500 years earlier, to be pedantic. But the light arrived to Earth in 1054. So what else happened in 1054? Oh yeah, the great Schism (http://en.wikipedia.org/wiki/East%E2%80%93West_Schism#Mutual_excommunication_of_1054).
Funny coincidence...
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
The second "larger" image was processed differently - more lightening of the dark end & over exposed. All the stars bloom in the new image as they've been enhanced stronger than the older image. Granted the internal filaments did move slightly, there is cheating to make it look more pronounced.
from 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
to 45 2F 6E 40 3C DF 10 71 4E 41 DF AA 25 7D 31 3F
Cool guys don't look at explosions.
We should all take this time to remember the brave folks who, thousands of years ago, had to self destruct their crab-class starship to save the universe from the Daleks.
This was first done in 1921
http://www.pnas.org/content/7/6/179.full.pdf+html
True, they didn't have animated gifs back then...
Not really. As the nebula expands it will cool. Over time it will become even more red than it is now. That is the ionized hydrogen emitting light. It will be the last thing to cool below a point of emission. In the earlier picture you can see that many elements were emitting light over a larger spectrum than it is today. Those sky blue sections you see are the previously emitting elements now refracting light. Blue in color because of how easily that wavelength refracts, just like it does in our atmosphere.
Ignore the parts that are differently visible and the color differences, and focus on the parts that are the same in both images.
You'll see that the elements from the earlier photo have moved away from the center of the nebula and this is visible relative to all the background stars.
G.
many features near the edge have not moved at all. It leads me to
think that in the later exposure, you are simply seeing details
that were not previously visible.
You have to drop your pants on a few dozen dubious tracker URLs and then it's a Vimeo video which is served from a a potato-powered server someplace.
There are probably a million lines of JavaScript that want to execute so that I can see what *should* be a two-frame animated GIF with a direct link. Remember? Remember when it'd be an a .EDU server someplace, just like that?
Sheesh. Shit like this just makes me want to unplug the whole web. My machine is fully capable of viewing the video, but I'm not going to jump through these hoops just to view it. Will somebody please turn it into the aforementioned GIF and host it someplace with a direct link that isn't trying to monetize every damn cycle on my CPU?
Anyone figure out how fast the "debris" is moving from the center? To see this kind of a change, on this scale, in such a short time, it must be mind-blowing fast!
neorush
Off topic but I really am annoyed with the hack web "programmers" that build web sites with a dozen or more cross site scripts. Here's the shit list from this latest atrocity:
facebook.com
google.com
google-analytics.com
outbrain.com
parsley.com
chartbeat.com
criteo.com
vimeo.com
twitter.com
washingtonpost.com
revsci.net
adsonar.com
cleanprint.com
wapolabs.com
grvcdn.com
echoenabled.com
content.ad
googleapis.com
amazon-adsystem.com
visualrevenue.com
vimeocdn.com
slate.com
That's 21 external javascript sites. There are probably more that would be pulled in if I enabled all these sites in NoScript. This is seriously pathetic.
I am becoming gerund, destroyer of verbs.
This is what I thought of, basically the newer telescope probably has updated optics and can take a finer grain of image, of course it will show more and seem like it has grown bigger.
I'm not sure if any of the parts of the parent's post are correct. Hydrogen won't be the last element to emit as it cools, as there are plenty of lower energy transitions in other elements, and even many elements there with lower ionization energies (e.g. iron and carbon). There are plenty of blue oxygen and iron lines that can be quite bright, especially if the gas is not in a thermal equilibrium due to ionization from emissions from the pulsar in the center. Additionally, the blue glow is not from Raleigh scattering in the sky, but has been shown to be synchrotron radiation from high speed electrons being stopped as they hit more dense plasma and gas.
Why the misinformation?! The background stars don't move, the nebula expands, the color is irrelevant. Watch it in black and white if you must.
A successful API design takes a mixture of software design and pedagogy.
I have heard it suggested that when Messier was compiling his list of things not to look at because they're not comets, the Crab Nebula was prominently in his list because it was significantly smaller and brighter in his day than it is now. It's far from conspicuous today...
...laura
I've also expanded over a 13 year period.
Table-ized A.I.
There are more comments bitching about the link than comments about the actual nebula. Even the nerds are disinterested in space these days...
There is a pretty wide variation in density, temperature and ionization across the nebula and its structures, which results in quite a variation in the emission spectra of different parts. The result is that you could take two different pictures at the same time, using different filters, and you can potentially see different parts of the nebula, and the size will look different as a result. There does looks like there is some clear movement of some structures, but that doesn't mean the color is irrelevant.
If you think color doesn't matter, compare this image with this image. They were both taken over the same nights in February 2008, but the latter has an H-alpha layer added in. There are stars in the former that look like they are outside the edge of the nebula, but in the latter now look like they are shining through part of the nebula.
I'm overwhelmed with regret that they did not, indeed, take a picture every week like I expected, or even every year.
Two pictures. And they made a VIDEO. For two pictures.
Seriously?
No. Firstly the colours are simply mapping different emissions to different wavelengths. The reddish picture is what it really looks like with the red being mostly Hydrogen Alpha and in part Ionised Sulphur emissions (both infrared). The yellowish picture maps Hydrogen Alpha to the green channel and Sulphur II to the red channel (result is yellow / brown). In either case the blue remains Ozone emissions. This has been labelled the Hubble Palette as that's how pictures came from the Hubble so you could separate the amount of Ha and SII in each nebula rather than mushing them all into red.
But really note that the stars don't move, however the actual details like the shock fronts visible in the detail actually seem to move out from the centre. The colour, camera quality, and even exposure is really irrelevant. You could have seen the same result on a well calibrated backyard telescope and a DSLR if someone was looking.
It does in this case. Red in the normal sense is Hydrogen Alpha and Ionised Sulphur when picked up on a colour camera. When narrow band imaging and mapping the emissions to the Hubble palette Hydrogen Alpha becomes green and Ionised Sulphur stays mapped to red. The result is that the red in the second picture is the same emissions as the yellow/brownish colours in the first pictures, and they clearly show expansion.
The colour has nothing to do with being two different scopes. It's to do with two different ways of mapping data. The reddish picture is what the nebula looks like on a colour camera. Ha and SII emissions from nebula are infrared and cameras map them to red. When doing narrow band imaging if you want to separate these emissions you can do it quite well the way Hubble did and map Ha to the green channel and SII to red.
This means the yellow in the first picture is the same emission as the red in the second picture, and take a look at the shock fronts in both frames and note that they have moved outward from the centre.
I think you missed the point. The ideas that there is visible expansion and that the details of filters (i.e. color) used is relevant, are not mutually exclusive. It is easily quite possible for different filters to produce the illusion of expansion, which is not the same as saying this image does not show expansion.
If someone says, "the colors look different, maybe these images were taken differently," the incorrect response is to say, "But the stars don't move and color is irrelevant." Of course the stars won't move if using different filters, that isn't a counter point to the idea they may have been filtered differently. Instead he could have said something closer to what you said, that in this case the colors are produced by very similar filters (disregarding that mapping them to different color channels will confuse some people more than others...).
If someone demonstrated an "anti-gravity balloon" and someone asks if it is filled with helium, you don't tell them, "It doesn't matter what a balloon is filled with," instead of maybe explaining in that case it was in a vacuum and that didn't matter in that case.
H-alpha is pretty solidly within the visible range, and the sulfur lines at 671 and 673 should be visible to nearly everyone. And it is pretty vague to say what a "color camera" does with infrared, as it depends on what particular filters they used. In my experience, near IR stuff tends to show up on many cameras as either white or in the blue channel, even down to ~800 nm part of the spectrum. This experience has comes from having used many consumer cameras as a cheap alignment tool for IR optics, and they seem to have surprising half-assed ways of filtering IR some times.
That could have been made more clear in the article, which briefly mentions using different filters, and links to the details of one photo, but not the other (unless I missed a link). Considering how often pop-sci explains or shows off images of other parts of the spectrum by contrasting them with visible images or different colors, some people are probably used to the idea that different colors (especially in false color cases, which are not always immediately obvious) or filters means things can look different. It is a perfectly relevant question or thing to consider, and is not resolved by looking at the lack of star movement or "watching it in black and white."
I wished people would ask more questions like that in my field of study, instead of just oohing and ahhing, or worse, chiding others for bringing up an important point to consider, even if it ends up not relevant to the particular example.
Hubble: Timelapse of V838 Monocerotis (2002-2006) [1080p]
"The NASA/ESA Hubble Space Telescope has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique "thin-section" through the interstellar dust around the star. This video morphs images of the light echo from the Hubble taken at multiple times between 2002 and 2006. The numerous whorls and eddies in the interstellar dust are particularly noticeable. Possibly they have been produced by the effects of magnetic fields in the space between the stars." (apologies if this is a re-post)
It's more like "Crap Nebula", duh!
So say we all