Search found 1061 matches

by VictorBorun
Thu Jan 07, 2021 7:11 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)
Replies: 28
Views: 10205

Re: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)

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...
by VictorBorun
Thu Jan 07, 2021 5:33 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)
Replies: 28
Views: 10205

Re: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)

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...
by VictorBorun
Thu Jan 07, 2021 5:22 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)
Replies: 28
Views: 10205

Re: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)

wow
a real galactic jewelry
An amberish bar with blue ends and a blue-ringed pearl at the center.
by VictorBorun
Mon Jan 04, 2021 3:11 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)
Replies: 28
Views: 10205

Re: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)

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...
by VictorBorun
Sun Jan 03, 2021 1:37 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)
Replies: 28
Views: 10205

Re: APOD: Galaxies and the South Celestial Pole (2021 Jan 01)

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...
by VictorBorun
Thu Dec 31, 2020 5:18 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Cosmic Latte: The Average Color of... (2020 Dec 27)
Replies: 30
Views: 12429

Re: APOD: Cosmic Latte: The Average Color of... (2020 Dec 27)

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...
by VictorBorun
Sun Dec 27, 2020 1:44 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Cosmic Latte: The Average Color of... (2020 Dec 27)
Replies: 30
Views: 12429

Re: APOD: Cosmic Latte: The Average Color of... (2020 Dec 27)

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...
by VictorBorun
Sun Dec 27, 2020 1:29 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Portrait of NGC 1055 (2020 Dec 24)
Replies: 15
Views: 5132

Re: APOD: Portrait of NGC 1055 (2020 Dec 24)

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...
by VictorBorun
Sat Dec 26, 2020 5:06 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Portrait of NGC 1055 (2020 Dec 24)
Replies: 15
Views: 5132

Re: APOD: Portrait of NGC 1055 (2020 Dec 24)

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...
by VictorBorun
Fri Dec 25, 2020 10:25 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)
Replies: 17
Views: 10643

Re: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)

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...
by VictorBorun
Tue Dec 22, 2020 11:26 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)
Replies: 17
Views: 10643

Re: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)

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?
by VictorBorun
Fri Dec 11, 2020 5:17 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)
Replies: 17
Views: 10643

Re: APOD: Simeis 147: Supernova Remnant (2020 Dec 10)

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 ...
by VictorBorun
Sat Dec 05, 2020 3:21 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Curly Spiral Galaxy M63 (2020 Dec 04)
Replies: 18
Views: 7248

Re: APOD: Curly Spiral Galaxy M63 (2020 Dec 04)

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...
by VictorBorun
Sat Dec 05, 2020 4:57 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Antennae Galaxies in Collision (2020 Dec 03)
Replies: 13
Views: 9336

Re: APOD: The Antennae Galaxies in Collision (2020 Dec 03)

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...
by VictorBorun
Sat Dec 05, 2020 4:15 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Curly Spiral Galaxy M63 (2020 Dec 04)
Replies: 18
Views: 7248

Re: APOD: Curly Spiral Galaxy M63 (2020 Dec 04)

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...
by VictorBorun
Fri Dec 04, 2020 2:39 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Antennae Galaxies in Collision (2020 Dec 03)
Replies: 13
Views: 9336

Re: APOD: The Antennae Galaxies in Collision (2020 Dec 03)

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...
by VictorBorun
Sun Nov 22, 2020 3:44 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)
Replies: 22
Views: 10105

Re: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)

made a "drying puddle anime" https://www.facebook.com/AstronomyPictureOfTheDay/posts/3505465126155590?comment_id=3506733752695394&reply_comment_id=3506840939351342&__cft__[0]=AZUODXtO2vZ1NL9m-rjI5Sxwp94YIsG6EeDbmbVC5DEuq_8XykFi95QeCUNY3GibdeJX3A0h6IjpX2Dyo3g8rQqccj2nO7xlA9GtiHJ1VeB...
by VictorBorun
Sun Nov 22, 2020 8:46 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)
Replies: 22
Views: 10105

Re: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)

made a "drying puddle anime" https://www.facebook.com/AstronomyPictureOfTheDay/posts/3505465126155590?comment_id=3506733752695394&reply_comment_id=3506840939351342&__cft__[0]=AZUODXtO2vZ1NL9m-rjI5Sxwp94YIsG6EeDbmbVC5DEuq_8XykFi95QeCUNY3GibdeJX3A0h6IjpX2Dyo3g8rQqccj2nO7xlA9GtiHJ1VeB...
by VictorBorun
Sun Nov 22, 2020 7:56 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)
Replies: 22
Views: 10105

Re: APOD: Dark Molecular Cloud Barnard 68 (2020 Nov 22)

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...
by VictorBorun
Mon Nov 16, 2020 2:06 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Edge-On Galaxy NGC 5866 (2020 Nov 15)
Replies: 10
Views: 4905

Re: APOD: Edge-On Galaxy NGC 5866 (2020 Nov 15)

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...
by VictorBorun
Sun Nov 15, 2020 6:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Edge-On Galaxy NGC 5866 (2020 Nov 15)
Replies: 10
Views: 4905

Re: APOD: Edge-On Galaxy NGC 5866 (2020 Nov 15)

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) ?
by VictorBorun
Fri Nov 13, 2020 3:15 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Tarantula Zone (2020 Nov 13)
Replies: 26
Views: 10490

Re: APOD: The Tarantula Zone (2020 Nov 13)

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...
by VictorBorun
Thu Nov 05, 2020 7:57 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: North of Orion's Belt (2020 Nov 05)
Replies: 6
Views: 3356

Re: APOD: North of Orion's Belt (2020 Nov 05)

I wish we had somethinng better than GAIA to gauge a star's distance from us.
Say some way to imply a star's angle diameter from weak blinking caused by interstellar gas fluctuations or rogue planetoids nanolensing
by VictorBorun
Thu Nov 05, 2020 7:45 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: North of Orion's Belt (2020 Nov 05)
Replies: 6
Views: 3356

Re: APOD: North of Orion's Belt (2020 Nov 05)

can a dark dusty pillar last 10 million years to drift a thousand ly away from the star that sculpted it?