Starship Asterisk*

How to guess the size of a distorted barred disk galaxy when the dark part is elusive? For now we have light matter sizes: SMC 7 kly, LMC 14 kly, with 75 kly between these binary system galaxies. Then again, some suppose SMC is in fact teared in two, with 30 kly between foreground and background shr...

Come to think of it, if we have a rotating globular cloud of constant density, its equatorial plane cross-section must be moving like a solid body. There can be strings or bars that don't get smeared by the difference in orbiting periods. Sadly real globular clouds are not dense enough and self-grav...

https://upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Rotation_curve_of_spiral_galaxy_Messier_33_%28Triangulum%29.png/1024px-Rotation_curve_of_spiral_galaxy_Messier_33_%28Triangulum%29.png https://lh3.googleusercontent.com/proxy/wzmYtSYW_NCmWR9be07bBo_IVO5ub-9iyRR3Z9WJj50bs-T9YmVEuXqR29Gzl_0GcT...

https://apod.nasa.gov/apod/image/1708/NGC1512inner_Hubble_960.jpg Through density waves, the bars rotate as solid bodies, even though they are not solid. As they rotate, they sweep up gas and channel it into two places: At the ends of the bar, which often see increased star formation, and into a sm...

wow
a real galactic jewelry
An amberish bar with blue ends and a blue-ringed pearl at the center.

Check out this video , which shows the formation of a spiral galaxy. Note how the galaxy gradually evolves a bar. Ann Video is great, thanks. But now I don't understand how come that the core, though low-gas and populated mostly with long-living stars, is solid enough to cunduct a density wave. A g...

https://asterisk.apod.com/download/file.php?id=38563&t=1 Ann I wonder if LMC is an ordinary flat gas/dust disk spiral galaxy with a bar at its core. What is a bar in a barred galaxy anyway? Is it a binary system of cores in the moment of merge? Is it a disk with another plane that we get to see...

Do I get it right? 1. Here on Earth we are biased. Let's take an observer in the middle of nowhere, in the center of a typical void. With a telescope, he'll get to see clusters of galaxies all around, say, 250 million ly away, or 100 times the distance of Andromeda galaxy. What mean spectrum that ob...

The resulting cosmic spectrum That 2002 publication https://arxiv.org/pdf/astro-ph/0110676 says it's bluish green though: "It is interesting to compute the perceived color of the cosmic spectrum to the human eye, using standard color matching functions CIE (1971, 1986). Integrating these throu...

Only rigid bodies can tidally lock. Are not the disk gas-rich galaxies rigid when: 1) alone and keeping themselves flat, smoothely whirling 2) run upon another body and conduct a mighty bing through their bodies Is Earth rigid, is the Earth's ocean rigid? And are lito- and hydrospheres going to tid...

The separation between NGC 1055 and M77 is about 442,000 light-years. Do I get it right: the disk galaxies in a binary system don't do a tidal lock. They pose like runaway disk saws about to saw each other in two. And the pair of NGC 1055 and M77 looks like a pair of identical twins at that. It wil...

Once the shock front forms, clumps of the material splash against the back of the shock front in an irregular pattern creating the mottled appearance. So the shock front is like a lamp light when some clumps cast shadows, that are irregular cones in 3d space, every one having the same center as the...

neufer wrote: ↑Fri Dec 11, 2020 5:35 pm
Quegli spaghetti are 1-dimensional intersections of 2-dimensional shock fronts.

http://asterisk.apod.com/viewtopic.php? ... 34#p308860

I just don't get it. To have a spherical shock front crossing another spherical shock front we must have two different centers, must we not?

I was wondering about the use of the descriptive phrase "looping filaments", aka "spaghetti". Wouldn't the "filaments" we are seeing be more likely to be the optical result of "edge darkening" of many overlapping bubbles of gas and dust? I wonder if there is ...

We know that there is a central black hole in the Milky Way because it is the only explanation for the orbits of the stars at the very center. Do those orbits prove that the central BH is not a binary system with a period of 10 hours, to ruin 5 hours exposure in 2017? Do those orbits prove that the...

The Dust comes from stars formation, OK. Ann and Chris, thanks for explaining. But is a normal car crush analogy in any way? Before the auto break system there were cars rotating after having tried to use breaks on a sleazy road. But even those unhappy cars could not rotate fast enough to rival with...

There is actually speculation that a central black hole might not exist? How could that even be possible? Well, are we really sure that there is a central BH in the Milky Way? The Event Horizon Telescope project tried to image it with few hours exposure and failed to get any crisp picture to publis...

This I find strange: how come the bridge is dustier than either of the tidal arms? And this is a question from driveline analogy: considering two colliding galaxies as a two rotating wheels coming to a point of clutch, does that friction accelerate the rotation, decelerate it, or both, or none of th...

made a "drying puddle anime" https://www.facebook.com/AstronomyPictureOfTheDay/posts/3505465126155590?comment_id=3506733752695394&reply_comment_id=3506840939351342&__cft__[0]=AZUODXtO2vZ1NL9m-rjI5Sxwp94YIsG6EeDbmbVC5DEuq_8XykFi95QeCUNY3GibdeJX3A0h6IjpX2Dyo3g8rQqccj2nO7xlA9GtiHJ1VeB...

made a "drying puddle anime" https://www.facebook.com/AstronomyPictureOfTheDay/posts/3505465126155590?comment_id=3506733752695394&reply_comment_id=3506840939351342&__cft__[0]=AZUODXtO2vZ1NL9m-rjI5Sxwp94YIsG6EeDbmbVC5DEuq_8XykFi95QeCUNY3GibdeJX3A0h6IjpX2Dyo3g8rQqccj2nO7xlA9GtiHJ1VeB...

https://scontent.fhen2-1.fna.fbcdn.net/v/t1.0-9/126315406_3451554238298996_2532111946056853504_n.jpg?_nc_cat=100&ccb=2&_nc_sid=dbeb18&_nc_eui2=AeF0w-IakDK0D1MlxrFh2nGnoBr--8LGVeKgGv77wsZV4kKnpR44FX76bJBdwARg46WgPsrVQPiTYpFRiS3I4S-m&_nc_ohc=MyfWgMSxdMAAX9pnade&_nc_ht=scontent.fhe...

What I thought when asking was: 1) curved protuberances of Sun are plasma magnetic loops as are some low density plasma loops a light year long near the center of the Milky Way. What if dust curls about the edge-on view of NGC 5866 were too…? Well dust as such is not one with magnetic field lines, b...

Are complex dust lanes magnetic loops ?

Can the mass of the central black hole be inferred from the size of the bulge (supposing the bulge formed after the gas was gone with the active nucleus's wind) ?

seems 1987A (bright star to the right and low besides the Tarantula) in 2020 looks dark https://www.facebook.com/AstronomyPictureOfTheDay/posts/3482273791808057?comment_id=3482950748407028&__cft__[0]=AZUeDHqe06NsiMlJHtTAI9tkR8GBX5HAideEhc3vDANomoBZndcb828yrJP6vFGNVZPJFPt2uhFr27wY4ldpaIiVs3N0C9_4...

Phobosians will find a way to keep their home in orbit.