Comments on: The dusty depths of a spectacular spiral galaxy

By: Picture Kaleidoscope 8/10/11 « Gloria Oliver

Picture Kaleidoscope 8/10/11 « Gloria Oliver — Sat, 13 Aug 2011 02:11:34 +0000

[...] Nate shared this article from Dicover Magazine with this awesome pic of a spiral [...]

By: Enlaces de Astronomía: Semana 01-08-2011 « Campos de Estrellas

Enlaces de Astronomía: Semana 01-08-2011 « Campos de Estrellas — Sun, 07 Aug 2011 19:56:13 +0000

[...] Galaxias: Could Reflected Radiation of Active Galactic Nuclei be the Long-Sought Missing Part of the Cosmic X-ray Background?. The dusty depths of a spectacular spiral galaxy. [...]

By: cesar

cesar — Fri, 05 Aug 2011 21:34:59 +0000

awesome!! thank god for smart people

By: bk_2

bk_2 — Tue, 02 Aug 2011 08:43:19 +0000

There’s another factor in effect here. The dust lanes on the far side of the galaxy are illuminated on the near side by the brilliant galaxy center. They reflect a lot of that starlight, so they are less dark than the near clouds, which are in sillouhette against the brilliance behind.

I think this was mentioned before in the context of NGC 7049, but I can’t find a reference yet.

By: Anchor

Anchor — Tue, 02 Aug 2011 07:26:10 +0000

I’m frankly amazed that Phil’s ‘explanation’ hasn’t been blazingly obvious to everyone long before HST was even a glimmer in our eye. The effect has been well known for almost as long as we’ve realized what ‘spiral nebulae’ were – vast collections of stars. I have known it for over 45 years and have used it as a means of quickly determining which edge of a galaxy obliquely oriented to our line-of-sight in an image was closer to us: obviously the far side dark clouds are typically washed out by the intervening halo stars which are more densely populated near the core. (Yes, John Sandlin #21 & 22 is quite right). Every semi-serious student of galaxies I know is familiar with this elementary aspect of galaxy geometry, that they are diffuse distributions of stars attended by extensive haloes. Glad to discover that Phil Plaitt “suddenly realized” it now too “after mulling it over for a moment”.

Sheesh.

By: Messier Tidy Upper

Messier Tidy Upper — Mon, 01 Aug 2011 23:55:44 +0000

Stunningly, superluminously magnificent. I love that image. Good thinking and probable explanation for the darkness of the nearer side dust lanes there too.

In something I’m considering making a tradition here at BA Central, here is your Monday morning jaw-dropping spiral galaxy: NGC 634 as seen by Hubble

I love that idea too. Please make it so!

Isn’t that something?

Yes, it is a whole galaxy rich in glowing stars, dark dust lanes and, probably, invisible other exoplanets in their trillions among other wonders all set upon an exceptional star field of the Black speckled with stars and some neat background galaxies too.

By: John Sandlin

John Sandlin — Mon, 01 Aug 2011 23:13:04 +0000

Here’s an image that demonstrates, sort of, what I mean. I made a 3D galaxy-like disk, a central bright ball, rings that would be stars, rings that would be dust, and a faint halo of stars. Depending on the angle, the farther dark rings (and star rings, for that matter) are obscured.

https://picasaweb.google.com/sandlin.john/StudyDustyGalaxy?authkey=Gv1sRgCPfWzO-Dxr6kbg#5636028548430652034

By: John Sandlin

John Sandlin — Mon, 01 Aug 2011 22:27:11 +0000

In Windows 7 the wall paper can auto change.

I have another thought on the lack of visible dust on the farther side. Don’t the disks have a slight change in thickness so that near the core the disk is thicker (north to south) and have more stars than toward the edges. This should help hide dust lanes on the far side and show them better on the near, depending on the degree of tilt. And the halo idea would certainly be a contributing factor as you’re looking through a denser star pattern to see the disk on the far side than the near.

It’d be like standing in front of a crowd of people arranged tall in back to short in front for the near side, and behind a similarly arranged crowd for the far side. Everyone is visible from the front. Only the tallest are visible from behind.

By: Photo: The Beauty of the Universe Around Us — In the Mind of Jason Thibeault

Photo: The Beauty of the Universe Around Us — In the Mind of Jason Thibeault — Mon, 01 Aug 2011 22:08:41 +0000

[...] http://blogs.discovermagazine.com/badastronomy/2011/08/01/the-dusty-depths-of-a-spectacular-spiral-g… [...]

By: Antonio Ceci

Antonio Ceci — Mon, 01 Aug 2011 21:34:13 +0000

Another amazing screensaver for my laptop!!!! Every day at 3.00 pm (Rome time) I open your webpage to read someting amazing about science and space… Every time you surprise me with something very very special!
Thank you Phil!