Search found 31 matches

by Tara_Li
Wed Jan 01, 2020 9:51 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Betelgeuse Imagined (2020 Jan 01)
Replies: 46
Views: 18330

Re: APOD: Betelgeuse Imagined (2020 Jan 01)

Could it be this confluence of cycles that triggers Betelguese?
by Tara_Li
Sat Nov 23, 2019 4:01 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Orion Rising (2019 Nov 22)
Replies: 5
Views: 2559

Re: APOD: Orion Rising (2019 Nov 22)

I like how the reflection makes it that much easier to actually pick out the stars that make up Orion per se.
by Tara_Li
Sat Nov 23, 2019 4:00 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Messier 61 Close Up (2019 Aug 28)
Replies: 18
Views: 9205

Re: APOD: Messier 61 Close Up (2019 Aug 28)

Galactic cores are usually quite compact, but the yellowish, elongated bulge (really a bar) of M61 is not that small. Not sure what you're identifying as the elongated bulge - I'm looking at the tiny, circular as far as I can tell, bright central spot that the dust lanes come right up to and touch ...
by Tara_Li
Thu Nov 21, 2019 10:50 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Messier 61 Close Up (2019 Aug 28)
Replies: 18
Views: 9205

Re: APOD: Messier 61 Close Up (2019 Aug 28)

To my eye, that core region looks abnormally small - is that an effect of the wavelength, or is the core just unusually compact? Galactic cores are usually quite compact, but the yellowish, elongated bulge (really a bar) of M61 is not that small. Not sure what you're identifying as the elongated bu...
by Tara_Li
Thu Nov 21, 2019 10:44 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Arp 273: Battling Galaxies from Hubble (2019 Nov 20)
Replies: 41
Views: 8556

Re: APOD: Arp 273: Battling Galaxies from Hubble (2019 Nov 20)

It's pretty simple. For reasons unknown, presumably aesthetic, the image processor chose to rotate the entire Hubble frame from the original orientation. That resulted in dead space in all four corners where there was no image data. So rather than leaving those areas blank (which would have been th...
by Tara_Li
Thu Nov 21, 2019 3:00 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Arp 273: Battling Galaxies from Hubble (2019 Nov 20)
Replies: 41
Views: 8556

Re: APOD: Arp 273: Battling Galaxies from Hubble (2019 Nov 20)

Nobody addressed the comment in one of the first posts here about repeated background elements. I see many of them, like a pair of faint edge-on galaxies near a bright orange point that appear in the top left, top right, and bottom just right of center. Are they lensed background galaxies (I’m sure...
by Tara_Li
Wed Aug 28, 2019 5:52 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Messier 61 Close Up (2019 Aug 28)
Replies: 18
Views: 9205

Re: APOD: Messier 61 Close Up (2019 Aug 28)

To my eye, that core region looks abnormally small - is that an effect of the wavelength, or is the core just unusually compact?
by Tara_Li
Thu Apr 04, 2019 11:39 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Gaia Stars of M15 (2019 Mar 28)
Replies: 25
Views: 15845

Re: APOD: The Gaia Stars of M15 (2019 Mar 28)

Actually, the GIF wouldn't need to be that much larger, really. Remember that most of the image data is identical between frames. So the only areas that need to vary between frames would be the variables - which are a very small segment of the image. Using difference overlaying, and limiting the are...
by Tara_Li
Fri Feb 01, 2019 3:12 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Twin Galaxies in Virgo (2019 Feb 01)
Replies: 23
Views: 10909

Re: APOD: Twin Galaxies in Virgo (2019 Feb 01)

One of the things I love about the really large pictures APOD posts is that you can often find interesting things in the background. For example - at about pixel 75,750, there's a sharp point of light surrounded by lots of fuzziness. It doesn't exactly look like the normal elliptical/spherical galax...
by Tara_Li
Thu Feb 25, 2016 8:34 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Highest, Tallest, and Closest to the... (2016 Feb 25)
Replies: 26
Views: 15352

Re: APOD: Highest, Tallest, and Closest to the... (2016 Feb 25)

Now, the question I have is - due to centrifugal force on the *atmosphere*, and the variations in local gravitation affecting the density profile of the atmosphere - is this peak actually the best one to peek through, as in the least atmosphere in the way? (And of course, light pollution is always a...
by Tara_Li
Fri Sep 18, 2015 4:40 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Plutonian Landscape (2015 Sep 18)
Replies: 44
Views: 5326

Re: APOD: A Plutonian Landscape (2015 Sep 18)

Can I presume the semi-circular streaks more or less parallel to the horizon are star trails? Or is the atmosphere of Pluto *VASTLY* more complicated than we ever imagined?
by Tara_Li
Sun Aug 17, 2014 5:08 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: No X-rays from SN 2014J (2014 Aug 16)
Replies: 20
Views: 28407

Re: APOD: No X-rays from SN 2014J (2014 Aug 16)

My understanding was that all three arose from General Relativity, and were essentially the same underlying phenomena appearing in different manners. I'm just surprised quantum theory doesn't throw in its own red shift source. (Or does it? Do photons lose energy through interactions with the backgr...
by Tara_Li
Sun Aug 17, 2014 12:47 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: No X-rays from SN 2014J (2014 Aug 16)
Replies: 20
Views: 28407

Re: APOD: No X-rays from SN 2014J (2014 Aug 16)

I have not heard red-shift explained this way before. It does not sound at all like the explanations I have heard before, namely that we see red-shift because (at the time of emission), the light source was moving relative to the velocity we have (when receiving the light wave). Their are different...
by Tara_Li
Sat Aug 16, 2014 8:35 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: No X-rays from SN 2014J (2014 Aug 16)
Replies: 20
Views: 28407

Re: APOD: No X-rays from SN 2014J (2014 Aug 16)

Here's the thing - there's *ALMOST* nothing there, but ... not quite. Look at the "before" inset. There's a somewhat diffuse glow, strongest on the left, with something of a waist before it brightens back up just a bit (mostly reddish). There's also a somewhat more compact source in the u...
by Tara_Li
Sat Aug 16, 2014 5:39 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: No X-rays from SN 2014J (2014 Aug 16)
Replies: 20
Views: 28407

Re: APOD: No X-rays from SN 2014J (2014 Aug 16)

Here's the thing - there's *ALMOST* nothing there, but ... not quite. Look at the "before" inset. There's a somewhat diffuse glow, strongest on the left, with something of a waist before it brightens back up just a bit (mostly reddish). There's also a somewhat more compact source in the up...
by Tara_Li
Fri Apr 04, 2014 4:41 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Along the Western Veil (2014 Apr 04)
Replies: 18
Views: 8596

Re: APOD: Along the Western Veil (2014 Apr 04)

Just be careful about looking at this with R/B anaglyph glasses. Freaky!
by Tara_Li
Wed Nov 20, 2013 10:37 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Heavy Black Hole Jets in 4U1630 47 (2013 Nov 20)
Replies: 58
Views: 13423

Re: APOD: Heavy Black Hole Jets in 4U1630 47 (2013 Nov 20)

Unless this star is very unusual, it is going to contain heavy metals, up to and including iron - and probably even a bit beyond. Iron contained in the star material gets drawn off into the accretion disk, spirals in and gets ejected in the disk... Who honestly *DIDN'T* expect to see iron & nic...
by Tara_Li
Wed Nov 20, 2013 4:07 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Heavy Black Hole Jets in 4U1630 47 (2013 Nov 20)
Replies: 58
Views: 13423

Re: APOD: Heavy Black Hole Jets in 4U1630 47 (2013 Nov 20)

Unless this star is very unusual, it is going to contain heavy metals, up to and including iron - and probably even a bit beyond. Iron contained in the star material gets drawn off into the accretion disk, spirals in and gets ejected in the disk... Who honestly *DIDN'T* expect to see iron & nick...
by Tara_Li
Sun Aug 18, 2013 4:08 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Skylab Over Earth (2013 Aug 18)
Replies: 24
Views: 6479

Re: APOD: Skylab Over Earth (2013 Aug 18)

*vaguely wonders why this discussion on alignment marks didn't take place in a separate thread over where the camera nuts hide* It's kind of sad, really, that we never launched Skylab B. Or a Skylab C. Three of them would give us as much pressurized volume as the ISS currently has. And since they'd ...
by Tara_Li
Sat Jun 01, 2013 5:09 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)
Replies: 40
Views: 9368

Re: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)

Eddies can appear in fluid dynamics but not, I think, when the dynamism of a system is driven by gravity. ... Except that aren't planets supposed to collapse from eddies in the dust clouds around the stars? Sure, there's some magnetic effects in play, but the primary force in the protoplanetary dis...
by Tara_Li
Fri May 31, 2013 1:21 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)
Replies: 40
Views: 9368

Re: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)

Eddies can appear in fluid dynamics but not, I think, when the dynamism of a system is driven by gravity. Any seeming eddy in an image of a galaxy will either be a background galaxy or a much smaller colliding galaxy, as in the image you linked to Ann. In that case I don't think eddy is quite the r...
by Tara_Li
Fri May 31, 2013 4:02 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)
Replies: 40
Views: 9368

Re: APOD: One Armed Spiral Galaxy NGC 4725 (2013 May 30)

One thing I find interested in a little knot in the arm of the galaxy, at about the 5:30 position. I can't quite tell if it's a small region of sub-rotation, or another galaxy in the background. Be kind of neat, though, to actually find a galaxy with a notable eddy spiral in one of its arms.
by Tara_Li
Mon Oct 29, 2012 12:23 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Phobos: Doomed Moon of Mars (2012 Oct 28)
Replies: 44
Views: 13873

Re: APOD: Phobos: Doomed Moon of Mars (2012 Oct 28)

rstevenson wrote:It's possible to see a lot given just a few pixels. Or rather, it's possible to imagine a lot given just a few pixels.
Arty_Fact.jpg
Rob
So very very true.
by Tara_Li
Mon Oct 29, 2012 12:22 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Phobos: Doomed Moon of Mars (2012 Oct 28)
Replies: 44
Views: 13873

Re: APOD: Phobos: Doomed Moon of Mars (2012 Oct 28)

BDanielMayfield wrote:I'm trying to find what ya'll are discussing, but were are the numbers (pixel coordinates?) you're using?

Bruce
They're pixels, yes - and my image editor (Gimp in this case) has a scale along the sides, and a "cursor position information window" that gives me the location.