Starship Asterisk*

Ok. Presumably the chirp wave at the end marks the moment when the two black holes became one? Does there exist a theory / model explaining the general shape of this chirp? It would be nice to say that "this is what GR predicted the fusion of two black holes to sound like (on the GW spectrum) ...

The interesting part of this picture for me is the bridge of blue star starting at IC 4970 and initially running downwards and to the left before curving around NGC 6872. I take this (and the disruption of NGC 6872's spiral arms) to indicate that IC 4970 has already made its closest pass to NGC 6872...

I'll bite on this one. I notice that the picture taker's company is located in Laurel, MD. And living in the DC area, it seems that the trees look right for being in the area. However, our area generally is not laid out in a grid except in the cities. But that is not a city scene. In any case, a loo...

This APOD is slightly mistaken. The tropical year (364.24219 days) is not the time it takes the Earth to go around the Sun, but instead the time it takes the Earth to go from on vernal equinox to the next. The sidereal year is how long the Earth takes to go around the Sun, and its length is 365.2563...

There is a problem here: The video is for New Horizons and not Fermi's gamma ray "rain".

I did find the Fermi video under the first link in the text. It is very interesting and worthy of being on APOD. I have the you get this APOD corrected quickly.

I think I will have what probably is the last word: The differences between pictures 1 and 3 can probably be chalked up to changing water levels and currents. However, the transient in picture 2 is another matter. Hopefully we will learn more about that over time. In the meantime, it is neat to see ...

Look carefully at the overall image. There appears to be a line of demarcation in first two images running from the center of the top of teh frame towards the bottom near the lower left corner. There is more "stuff" to the right of that line than to the left. In the last picture, the line ...

There is something about the contrast in this image that reveals something interesting: There appear to be two dust lanes in this image. What appears to be the foreground dust land starts on the upper right side of the Milky Way. As it come to the central bulge area, it heads downward and around th...

There is something about the contrast in this image that reveals something interesting: There appear to be two dust lanes in this image. What appears to be the foreground dust land starts on the upper right side of the Milky Way. As it come to the central bulge area, it heads downward and around the...

Awesome detail...very clear picture... Two throwing stars colliding... If two galaxies collide, and no one takes a picture..... :?: One observation...to me, it appears where the collision takes place, 2207's arms are pushed up and away from IC2163...some stars from 2207 trail through and behind IC2...

Dude, it's just a galaxy. Accretion discs are too small to ever image directly. Go ahead and search for pictures. You won't find anything but concept art. Then what would you say that the ring is around the center is? Also, I will direct you to http://en.wikipedia.org/wiki/Accretion_disc which has ...

It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk. Nope. There is no mechanism to pull anything into the center. And an accretion disc around a central massive black hole woul...

It looks to me like a lot of gas and dust are being pulled into the center of the galaxy. Indeed there is a ring around the central object that may well be an accretion disk. This movement of mass from the outer reaches of the bar towards the center may well be behind the phenomenon of jets 1 and 3....

As best I can tell, the small galaxy at the bottom of the photo IS the intruder galaxy. There is a bridge running between the cores of the two galaxies! It comes out of the central code at 6:00, sweeps up past the 2:00 position (where what I think is a tidal tail is being mistaken for the intruder)...

As best I can tell, the small galaxy at the bottom of the photo IS the intruder galaxy. There is a bridge running between the cores of the two galaxies! It comes out of the central code at 6:00, sweeps up past the 2:00 position (where what I think is a tidal tail is being mistaken for the intruder),...

I have my own views if how galaxies merge, and so I have a different interpretation on this altogether. I do agree this this is a galaxy merger, and that the two original galaxies are stretched out in this image, with their cores merging in the center. However, when I see pictures of galaxies mergin...

zorts wrote:This is, indeed, a cool video clip - but I like it better when APOD sticks to straightahead astronomy.

I will second that.

Chris Peterson, your reply to Vincent Pinto is not really an answer to what he said. What studies show that evolutionary processes make this kind of structure essentially inevitable? How could you have evolution without replicating DNA? If, somehow, you had a DNA molecule appear in a living cell, i...

I'm not very impressed by this simulation. No central bulge (and at least an insignificant one), no dust lanes, and no bridges between the centers of the galaxies after a close encounter. So I see there as being a long ways to go here.

The growing nebula in the center reminds me more of the Eta Carinae nebula than anyting else. Maybe this two-lobed structure will evolve into a more "normal" looking supernova remnant, but I still find the similarity to be striking.

Chris Peterson wrote: fusion isn't what powers a star in any case; the energy source is gravity That I will politely take issue with. While the release of gravitational potential energy can act as an energy source, what powers the stars very much is nuclear fusion, with E=mc 2 showing up as the diff...

[T]he Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. I find this to be a very odd statement, since it takes added energy coming from the stellar core for the outer layers to be expelled in the first place. If the core is out nu...

[T]he Dumbbell Nebula, is a planetary nebula, the type of nebula our Sun will produce when nuclear fusion stops in its core. I find this to be a very odd statement, since it takes added energy coming from the stellar core for the outer layers to be expelled in the first place. If the core is out nu...

I think that the case against the two being related becomes much stronger when you can see the initiating region. Maybe this is coincidence, but with the occultation disk in place, what you see is comet heading and CME going out on the comet's trajectory. That makes asking if the two are related mak...

Here is a full screen version of that frame. Once again, notice the anomalous flare at 280 degrees. I'm sure that this is the start of the CME coincident with the comet's death.