Starship Asterisk*

Case wrote: ↑Sat Feb 19, 2022 4:09 pm

In the circle (top): Position of Arp 273 and HD 14511 on the sky.

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XgeoX wrote: ↑Sat Feb 19, 2022 12:11 pmDoes anybody know if that beautiful bright golden star to the left in the photo is H14511?

HD 14511, yes. An 8.8 magnitude G5 star¹ at 444 parsec (1448 light-years) distance, as derived from Gaia data. (Previous estimates put it farther away.) [¹ thought to be a binary or multiple star system, but not visible as such in today’s image.]

Chris Peterson wrote: ↑Sun Feb 20, 2022 11:26 pm

neufer wrote: ↑Sun Feb 20, 2022 10:27 pm

Ann wrote: ↑Sun Feb 20, 2022 6:45 pm
See that big gap between the larger galaxy's inner and outer arms? It makes sense to me that something may have passed through that gap to widen it. My guess is that this is what astronomers think.

My guess is that most astronomers think that these relatively undisturbed galaxies are simply passing by each other... although at a close enough distance that their outer edges are pulled out of their initial central planes by tidal interaction.

That's what I'd think. If one had passed between the core and an arm of the other the entire thing would be one big mess, like the Tadpoles or Mice.

neufer wrote: ↑Sun Feb 20, 2022 10:27 pm

Ann wrote: ↑Sun Feb 20, 2022 6:45 pm
See that big gap between the larger galaxy's inner and outer arms? It makes sense to me that something may have passed through that gap to widen it. My guess is that this is what astronomers think.

My guess is that most astronomers think that these relatively undisturbed galaxies are simply passing by each other... although at a close enough distance that their outer edges are pulled out of their initial central planes by tidal interaction.

Ann wrote: ↑Sun Feb 20, 2022 6:45 pm
See that big gap between the larger galaxy's inner and outer arms? It makes sense to me that something may have passed through that gap to widen it. My guess is that this is what astronomers think.

APOD Robot wrote: ↑Sat Feb 19, 2022 5:06 am Peculiar Galaxies of Arp 273

Explanation: Their distorted appearance is due to gravitational tides as the pair engage in close encounters. The peculiar galaxies of Arp 273 may offer an analog of their far future encounter.

https://en.wikipedia.org/wiki/Close_encounter#Close_Encounters_of_the_Second_Kind wrote:
<<Close Encounters of the Second Kind: A UFO event in which a physical effect is alleged; this can be interference in the functioning of a vehicle or electronic device, animals reacting, a physiological effect such as paralysis or heat and discomfort in the witness, or some physical trace like impressions in the ground, scorched or otherwise affected vegetation, or a chemical trace.>>

VictorBorun wrote: ↑Sun Feb 20, 2022 12:26 pm

Ann wrote: ↑Sat Feb 19, 2022 10:51 am Note the mini-spiral in the arm of UGC 1810 at upper right.

Seems embedded or piercing all right!
If we rotate Hubble's pic by 8.5° counter-clockwise as to make the North direct to the observer and then stretch a little,
we can see the central planar part of UGC 1810 (unlike the whole 3D rose button made tidally) as perfectly round.
And the third galaxy, a spiral dwarf, is clearly meddling with an arm.
Arp 273..jpg

What I don't get is why they say that the stem of the flower-like composition, UGC 1813, is the one that actually passed through the larger one.
If the space were empty there would be no way to tell which one is standing still and which one is passing.
Now there may be some ram pressure for some galaxies to make the difference, but is there any for Arp 273 flower-like system?

Chris Peterson wrote: ↑Sun Feb 20, 2022 2:12 pm

johnnydeep wrote: ↑Sun Feb 20, 2022 2:00 pm

Chris Peterson wrote: ↑Sun Feb 20, 2022 2:11 am
It looks to me like the diffraction spikes were added for aesthetic reasons, and are not in the actual data.

How did you surmise that? Is the raw unprocessed photo available (I couldn't find it after a little searching), or is is just that only those two much brighter stars show diffraction spikes, and no other stars have any sign of them?

Two reasons. First, they don't look like real diffraction spikes, which are not so uniform either in intensity or color. Second, the instrument that was used to collect the data does not have a spider mounted secondary to produce spikes.

johnnydeep wrote: ↑Sun Feb 20, 2022 2:00 pm

Chris Peterson wrote: ↑Sun Feb 20, 2022 2:11 am

E Fish wrote: ↑Sun Feb 20, 2022 1:54 am

Thanks so much for the explanation! I knew it wasn't a Hubble image, but you had excellent details in your image and it definitely is beautiful. The reason I was wondering was because there were other stars with diffraction spikes in your image but that one didn't have them which was why it was harder to determine its nature.

It looks to me like the diffraction spikes were added for aesthetic reasons, and are not in the actual data.

How did you surmise that? Is the raw unprocessed photo available (I couldn't find it after a little searching), or is is just that only those two much brighter stars show diffraction spikes, and no other stars have any sign of them?

Chris Peterson wrote: ↑Sun Feb 20, 2022 2:11 am

E Fish wrote: ↑Sun Feb 20, 2022 1:54 am

Thirteen wrote: ↑Sat Feb 19, 2022 8:33 pm

Original photographer here!

First, thanks so much to the APOD team for the consideration and feature. I'll try to address some of the questions regarding my image. First, in regards to the star that's been confused with another galactic core, the reason it looks so much different than the Hubble image is that this was shot with my rather modest 8" Celestron EdgeHD telescope. The combination of smaller optics and turbulent suburban skies conspires to blur the stars significantly. Though the results can't really compare to Hubble, I did have excellent (by my standards) conditions when photographing this, allowing me to extract impressive details (again by my standards). I hope you enjoyed it as much as I did.

If you want to read my original description and details about the gear, you can find it here...
https://www.instagram.com/p/CZ-YkhsJQWE ... _copy_link

Thanks so much for the explanation! I knew it wasn't a Hubble image, but you had excellent details in your image and it definitely is beautiful. The reason I was wondering was because there were other stars with diffraction spikes in your image but that one didn't have them which was why it was harder to determine its nature.

It looks to me like the diffraction spikes were added for aesthetic reasons, and are not in the actual data.

Ann wrote: ↑Sat Feb 19, 2022 10:51 am Note the mini-spiral in the arm of UGC 1810 at upper right.

E Fish wrote: ↑Sun Feb 20, 2022 1:54 am

Thirteen wrote: ↑Sat Feb 19, 2022 8:33 pm

Original photographer here!

First, thanks so much to the APOD team for the consideration and feature. I'll try to address some of the questions regarding my image. First, in regards to the star that's been confused with another galactic core, the reason it looks so much different than the Hubble image is that this was shot with my rather modest 8" Celestron EdgeHD telescope. The combination of smaller optics and turbulent suburban skies conspires to blur the stars significantly. Though the results can't really compare to Hubble, I did have excellent (by my standards) conditions when photographing this, allowing me to extract impressive details (again by my standards). I hope you enjoyed it as much as I did.

If you want to read my original description and details about the gear, you can find it here...
https://www.instagram.com/p/CZ-YkhsJQWE ... _copy_link

Thanks so much for the explanation! I knew it wasn't a Hubble image, but you had excellent details in your image and it definitely is beautiful. The reason I was wondering was because there were other stars with diffraction spikes in your image but that one didn't have them which was why it was harder to determine its nature.

Thirteen wrote: ↑Sat Feb 19, 2022 8:33 pm

Original photographer here!

First, thanks so much to the APOD team for the consideration and feature. I'll try to address some of the questions regarding my image. First, in regards to the star that's been confused with another galactic core, the reason it looks so much different than the Hubble image is that this was shot with my rather modest 8" Celestron EdgeHD telescope. The combination of smaller optics and turbulent suburban skies conspires to blur the stars significantly. Though the results can't really compare to Hubble, I did have excellent (by my standards) conditions when photographing this, allowing me to extract impressive details (again by my standards). I hope you enjoyed it as much as I did.

If you want to read my original description and details about the gear, you can find it here...
https://www.instagram.com/p/CZ-YkhsJQWE ... _copy_link

De58te wrote: ↑Sat Feb 19, 2022 5:30 pm Another APOD day and again I am confused by the explanation. It mainly describes the ARP 273 galaxies but it also says that nearby is the Andromeda galaxy. That must be the one in the top left corner because I don't see any other galaxies nearby. However it is said that the Andromeda is the most distant light that we can see with the naked eye. My question is if we can see the Andromeda galaxy by eye and yet the Arp 273 galaxies are at least 4 or 5 times larger than Andromeda in this photograph, then how come we can't see the Arp galaxies by naked eye?

E Fish wrote: ↑Sat Feb 19, 2022 3:30 pm

VictorBorun wrote: ↑Sat Feb 19, 2022 5:53 am "the bright cores"
There are just two galactic cores, are not they?
Arp 273.png

That is exactly what I was going to ask. I'm glad that it's already been asked and answered! That's a beautiful image today.

So in the two pictures that Ann provided, it seems obvious that the other blob was actually a foreground star. Does anyone know what was done differently with the processing to change its appearance so much in today's APOD?

E Fish wrote: ↑Sat Feb 19, 2022 3:30 pm

VictorBorun wrote: ↑Sat Feb 19, 2022 5:53 am "the bright cores"
There are just two galactic cores, are not they?
Arp 273.png

That is exactly what I was going to ask. I'm glad that it's already been asked and answered! That's a beautiful image today.

So in the two pictures that Ann provided, it seems obvious that the other blob was actually a foreground star. Does anyone know what was done differently with the processing to change its appearance so much in today's APOD?

De58te wrote: ↑Sat Feb 19, 2022 5:30 pm Another APOD day and again I am confused by the explanation. It mainly describes the ARP 273 galaxies but it also says that nearby is the Andromeda galaxy. That must be the one in the top left corner because I don't see any other galaxies nearby. However it is said that the Andromeda is the most distant light that we can see with the naked eye. My question is if we can see the Andromeda galaxy by eye and yet the Arp 273 galaxies are at least 4 or 5 times larger than Andromeda in this photograph, then how come we can't see the Arp galaxies by naked eye?

XgeoX wrote: ↑Sat Feb 19, 2022 12:11 pmDoes anybody know if that beautiful bright golden star to the left in the photo is H14511?

VictorBorun wrote: ↑Sat Feb 19, 2022 5:53 am "the bright cores"
There are just two galactic cores, are not they?
Arp 273.png

VictorBorun wrote: ↑Sat Feb 19, 2022 5:53 am "the bright cores"
There are just two galactic cores, are not they?

Click to view full size image