APOD: Seyfert's Sextet (2013 Dec 10)

[smitty]

Can't help being curious about the bright pair (perhaps a binary star pair?) to the right and slightly above center in the image. The leftmost member of the pair appears to have a slightly yellowish tint, whereas the other has a bluer tint. I'm assuming this pair is unrelated to Seyfert's Sextet, but if anyone can say more regarding what's known about the pair it would be appreciated. Thanks in advance for any enlightenment! What an exciting universe we inhabit! Never a dull moment.

[geckzilla]

Can't help being curious about the bright pair (perhaps a binary star pair?) to the right and slightly above center in the image. The leftmost member of the pair appears to have a slightly yellowish tint, whereas the other has a bluer tint. I'm assuming this pair is unrelated to Seyfert's Sextet, but if anyone can say more regarding what's known about the pair it would be appreciated. Thanks in advance for any enlightenment! What an exciting universe we inhabit! Never a dull moment.

I noticed that too. I was thinking that it could actually be a sort of bi-polar lobed structure with a dense toroid of dust around the center which creates the illusion of two bright stars next to one another. Or it could just be two bright stars. As far as I can tell, it's uncatalogued, or at least a quick SIMBAD query provided no result for it.

[smitty]

Thanks, geckzilla. The slight specular spikes on the pair suggests that they're nearer us, perhaps within our Milky Way? I recall seeing a beautiful yellow-purple pair of binary stars somewhere in the night sky, but don't recall offhand exactly where. Lyra perhaps?

[Chris Peterson]

Thanks, geckzilla. The slight specular spikes on the pair suggests that they're nearer us, perhaps within our Milky Way? I recall seeing a beautiful yellow-purple pair of binary stars somewhere in the night sky, but don't recall offhand exactly where. Lyra perhaps?

Albireo, I would guess, in Cygnus. The contrasting colors, yellow and blue, make the color much more apparent than we'd normally notice if the stars were isolated.

[tomatoherd]

Which reminds me: do astronomers ever use the aid of binocular vision? For instance, an image by Hubble taken with earth on one side of the sun, and repeated 6 months later on the far side, would each be 2 AU apart, and might be enough separation to give a 3D effect if the images were then viewed separately in a right and left human eye, like the old stereoscopes.

Nothing of astronomical interest outside our solar system is close enough to allow for a visually stereoscopic image given a baseline of only 2 AU. The nearest star shows an annual parallax of less than one arcsecond. Stars in the Orion Nebula have parallaxes on the order of one milliarcsecond. We're talking about the sort of stereoscopic views of those objects that you get of the Moon using your eyes.

You are mostly correct. One light year is to 2 AU roughly the same ratio as half a mile is to the space between our eyes, ~32,000 to 1. Alpha Centuri, at 4 ly, would be similar to our vision at 2 miles, where stereo vision begins to be less important. I had never done the math before. There are no visually interesting things between our solar system and the nearest star.

[smitty]

Chris, yes, now that you mention it, Albireo it is! Thank you for refreshing my memory. What a beautiful pair, even in a small telescope!

[Ron-Astro Pharmacist]

Well done geckzilla. So, the tightly packed elliptical feline galaxy (which looks in danger of being sucked into a black hole) is part of the local fluff, and everything else is light years away and aeons ago. Got it!

And yay to cats!

Ann

Around our house we have dual elliptical Catalexies only in "white" holes; each with thier own physicis

[geckzilla]

If it fits, we sits.

[owlice]

If we sits, it fits.

[Anthony Barreiro]

Chris, yes, now that you mention it, Albireo it is! Thank you for refreshing my memory. What a beautiful pair, even in a small telescope!

The sky is full of binary and multiple star systems, and many of them are quite beautiful. As a huge cloud of gas and dust collapses under its own gravity, it's much easier for one little rotating pocket of gas and dust in the cloud to collapse enough to trigger hydrogen fusion (the birth of a star!) if it is mutually orbiting another very dense pocket of gas and dust. The two rotating pockets of stuff can put their angular momentum into orbiting around one another rather than needing to conserve it entirely within their own little pockets. Our Sun is rather uncommon in being a single star. (Conservation of angular momentum is also involved in the formation of planets around protostars, and now we are learning that planets seem very common.)

Other beautiful double and multiple stars visible through a small telescope during this season include Gamma Andromedae at the northeastern end of Andromeda's brighter leg, Castor in Gemini, and Sigma Orionis in the eastern end of Orion's belt.

By the way, today's apod is a beautiful image! If anybody is in touch with the creator, please give her my regards!

[geckzilla]

If we sits, it fits.

Maybe.

[owlice]

See? Fits!

Screen shot 2013-12-10 at 3.20.10 PM.png (72.85 KiB) Viewed 1981 times

Screen shot 2013-12-10 at 3.22.15 PM.png (99.45 KiB) Viewed 1981 times

[Ron-Astro Pharmacist]

I bet that cat's name is "Super Nova"

[smitty]

Other beautiful double and multiple stars visible through a small telescope during this season include Gamma Andromedae at the northeastern end of Andromeda's brighter leg, Castor in Gemini, and Sigma Orionis in the eastern end of Orion's belt.

Thank you for the tips on other pretty binaries, Anthony. I'll check them out sometime. Thanks also for the info on binary star formation, etc. Very interesting and helpful.

[geckzilla]

I bet that cat's name is "Super Nova"

If you were referring to the posts above yours, his name is actually Maru, which means round or circle.

[Ron-Astro Pharmacist]

by geckzilla » Tue Dec 10, 2013 2:01 pm

Ron-Astro Pharmacist wrote:
I bet that cat's name is "Super Nova"

If you were referring to the posts above yours, his name is actually Maru, which means round or circle.

No - just taking a guess. Maru is quite the character. The yellow one is round too and also likes squeezing into tight places with way too much mass to accomplish the feat. He should have been named Nova. And the other one is just the opposite - maybe Avon?? They are symmetric cats - photographically and personality-wise

[Anthony Barreiro]

Other beautiful double and multiple stars visible through a small telescope during this season include Gamma Andromedae at the northeastern end of Andromeda's brighter leg, Castor in Gemini, and Sigma Orionis in the eastern end of Orion's belt.

Thank you for the tips on other pretty binaries, Anthony. I'll check them out sometime. Thanks also for the info on binary star formation, etc. Very interesting and helpful.

You're welcome, Smitty. I hope the discussion of stars isn't too distracting from pictures of cats.

[smitty]

You're welcome, Smitty. I hope the discussion of stars isn't too distracting from pictures of cats.

Well . . . now that you mention it, Anthony, I was beginning to wonder whether perhaps I'd accidentally logged on to Facebook rather than an APOD discussion forum. I've noticed that these discussions frequently stray pretty far afield of late. I guess we can't set our expectations for serious discussions too high these days without risking some degree of disappointment. Maybe it's a generational thing?

[geckzilla]

Well . . . now that you mention it, Anthony, I was beginning to wonder whether perhaps I'd accidentally logged on to Facebook rather than an APOD discussion forum. I've noticed that these discussions frequently stray pretty far afield of late. I guess we can't set our expectations for serious discussions too high these days without risking some degree of disappointment. Maybe it's a generational thing?

If you are trying to imply there are a bunch of young whippersnappers running around the forum ruining discussions with cats, you are mistaken. I would guess that the average age of an Asteriskian is greater than 40.

[BDanielMayfield]

Great APOD today. It makes great wallpaper too, having a convenient place in the lower left hand corner were you can put your icons so they won’t cover any of the image. (Turning lemons into lemon-aid.)

[rstevenson]

Well . . . now that you mention it, Anthony, I was beginning to wonder whether perhaps I'd accidentally logged on to Facebook rather than an APOD discussion forum. I've noticed that these discussions frequently stray pretty far afield of late. I guess we can't set our expectations for serious discussions too high these days without risking some degree of disappointment. Maybe it's a generational thing?

If you are trying to imply there are a bunch of young whippersnappers running around the forum ruining discussions with cats, you are mistaken. I would guess that the average age of an Asteriskian is greater than 40.

Which doesn't say anything about our being grown up.

Rob

[Chris Peterson]

Well . . . now that you mention it, Anthony, I was beginning to wonder whether perhaps I'd accidentally logged on to Facebook rather than an APOD discussion forum. I've noticed that these discussions frequently stray pretty far afield of late. I guess we can't set our expectations for serious discussions too high these days without risking some degree of disappointment. Maybe it's a generational thing?

These discussions go where they go. Where the discussers take them. Want more serious science? Offer some up, or ask a question. I guarantee you'll get seriousness.

[Tetrodehead]

If it's the densest group of galaxies, why no gravitational lensing?

[Chris Peterson]

If it's the densest group of galaxies, why no gravitational lensing?

This cluster is very close at 190 Mly (z = 0.14). The vast majority of gravitational lenses are z > 0.3, or more than 4 billion light years away. As close as NGC 6027 is, a source galaxy would have to be perfectly placed to see even a tiny distortion.

[Galaxian]

Thesextet actually contains only four interacting galaxies, though. Near the center of this Hubble Space Telescope picture, the small face-on spiral galaxy lies in the distant background and appears only by chance aligned with the main group. Also, the prominent condensation on the upper left is likely not a separate galaxy at all, but a tidal tail of stars flung out by the galaxies' gravitational interactions.

Are we sure the deep-diving blue whale at centre-bottom of the group is part of the interaction? I have a feeling it, too, is background but not as far from the group as the grand face-on spiral.
According to this the blue whale component, "C", has a slightly higher red shift than the rest of the group. Could that make it as far from them as M31 is from us and thus non-interacting?
We really need a 3-d, stereoscopic view. say from 90-degrees or more from our present line of sight.
Another good candidate for FTL.
Anyway, this is a beautiful image. Thank you.