by florid_snow » Tue Jun 18, 2024 11:22 pm
VictorBorun wrote: ↑Tue Jun 18, 2024 7:17 pm
Fast Eddie wrote: ↑Tue Jun 18, 2024 2:44 pm
The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?
to answer that we need to recognize the star field. Is there a star field recognition software?
Ah well, given the scale of the frame, near the horizon, northern hemisphere summer, there's only one globular cluster it could possibly be, that is the greatest cluster of them all, Omega Centauri. This is confirmed by the three bright blue stars that form a triangle above and to the left, they are the characteristic finder stars for Omega Centauri, I had to look these up, they are Mu, Nu, and Phi Centauri.
And now that I'm zooming into the pixels and comparing with Stellarium around the region, I think the photographer has at least doubled the star field, just about an hour apart, probably they stacked all exposures for the jets. Look closely and you'll see that central triangle of blue stars above Omega Centauri has an identical double of itself, just where we would expect it to be an hour later. So that means what appears to be a second dimmer globular cluster to the bottom right is actually just Omega Centauri again on another exposure an hour later,
dimmed by haze near the horizon.
Edit: wait, maybe this is a partial answer to your question about exposure time, the photographer included the second omega centauri because it is partially behind one of the jets, so the amount that it's dimmer must be representative of how much brighter the jets are than the globular cluster. So these jets are actually not that bright, at least from this distance, since they can't completely outshine a globular cluster that usually requires binoculars.
Very beautiful picture and great effort by the photographer, thanks to them and APOD for sharing!
[quote=VictorBorun post_id=339727 time=1718738240 user_id=145500]
[quote="Fast Eddie" post_id=339725 time=1718721883]
The image is striking (pun intended). The number of Jets is a good question. It appears that there are 5 with 2 converging and one (on the right) diverging. But, I am wondering what is the bright object in the middle of the frame?
[/quote]
to answer that we need to recognize the star field. Is there a star field recognition software?
[/quote]
Ah well, given the scale of the frame, near the horizon, northern hemisphere summer, there's only one globular cluster it could possibly be, that is the greatest cluster of them all, Omega Centauri. This is confirmed by the three bright blue stars that form a triangle above and to the left, they are the characteristic finder stars for Omega Centauri, I had to look these up, they are Mu, Nu, and Phi Centauri.
And now that I'm zooming into the pixels and comparing with Stellarium around the region, I think the photographer has at least doubled the star field, just about an hour apart, probably they stacked all exposures for the jets. Look closely and you'll see that central triangle of blue stars above Omega Centauri has an identical double of itself, just where we would expect it to be an hour later. So that means what appears to be a second dimmer globular cluster to the bottom right is actually just Omega Centauri again on another exposure an hour later, [s]dimmed by haze near the horizon.[/s]
Edit: wait, maybe this is a partial answer to your question about exposure time, the photographer included the second omega centauri because it is partially behind one of the jets, so the amount that it's dimmer must be representative of how much brighter the jets are than the globular cluster. So these jets are actually not that bright, at least from this distance, since they can't completely outshine a globular cluster that usually requires binoculars.
Very beautiful picture and great effort by the photographer, thanks to them and APOD for sharing!