Search found 2948 matches

by johnnydeep
Sat Jun 01, 2024 6:41 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Stereo Helene (2024 Jun 01)
Replies: 1
Views: 175

Re: APOD: Stereo Helene (2024 Jun 01)

Ok, can anyone explain to me why exactly it is that Helene is so "appropriate named"? I get from the links that it's something to do with John Herschel suggesting that the moons of Saturn be associated with mythical brothers and sisters of Cronus/Cronos/Kronos/Saturn; Trojan satellites and...
by johnnydeep
Sat Jun 01, 2024 4:00 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 28
Views: 910

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

It's complicated. W-R stars blow off a lot of material which often generates a local nebula, similar in some ways to a planetary nebula. But they can certainly exist within existing nebulas. I think we're seeing both of those here. The "fingery" blue ring is clearly from the W-R star, but...
by johnnydeep
Fri May 31, 2024 6:36 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 28
Views: 910

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

Is the source of the gas in prominent blue arc at the upper left the W-R star? Or is that just gas that happened to be in the vicinity? It's complicated. W-R stars blow off a lot of material which often generates a local nebula, similar in some ways to a planetary nebula. But they can certainly exi...
by johnnydeep
Fri May 31, 2024 6:14 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Nebulous Realm of WR 134 (2024 May 31)
Replies: 28
Views: 910

Re: APOD: The Nebulous Realm of WR 134 (2024 May 31)

Is the source of the gas in prominent blue arc at the upper left the W-R star? Or is that just gas that happened to be in the vicinity?
by johnnydeep
Thu May 30, 2024 6:22 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Lunar Corona over Paris (2024 May 30)
Replies: 12
Views: 572

Re: APOD: A Lunar Corona over Paris (2024 May 30)

There is a copyright on the actual lighting (at night) of the Eiffel Tower since it has an artistic twist. As a result, one cannot take photos of the Eiffel Tower lit at night and provide licensing for commercial purposes thereafter. The credit and copyright in the APOD is in relation to the photog...
by johnnydeep
Thu May 30, 2024 4:26 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Lunar Corona over Paris (2024 May 30)
Replies: 12
Views: 572

Re: APOD: A Lunar Corona over Paris (2024 May 30)

Astronymus wrote: Thu May 30, 2024 2:16 pm Illuminated Eiffel Tower at nighttime without special copyright disclaimer. That could mean trouble if the photo is used commercially.
What do you mean? The image is attributed to "Image Credit & Copyright: Valter Binotto". Isn't that enough?
by johnnydeep
Wed May 29, 2024 5:58 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Stairway to the Milky Way (2024 May 29)
Replies: 11
Views: 633

Re: APOD: Stairway to the Milky Way (2024 May 29)

Or perhaps it is NGC 3603 (and maybe NGC 3576) that are the bar-end enhancements of the southern Milky Way? Well, we are still in Carina. Do the distances (from Wikipedia) to NGC 3603 (20,000 ly) and NGC 3576 (9,000 ly) jibe with either or both of them being physically in the "bar-end"? E...
by johnnydeep
Tue May 28, 2024 9:02 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Solar X Flare as Famous Active... (2024 May 28)
Replies: 16
Views: 821

Re: APOD: Solar X Flare as Famous Active... (2024 May 28)

That's not the flare (which was at the surface), but is probably a CME thrown off by the flare. CMEs at angles like that can hit the Earth, because of the complex way that the Sun's and Earth's magnetic fields interact , but this CME is not expected to hit Earth. Thanks. Once again, reality is more...
by johnnydeep
Tue May 28, 2024 8:37 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Solar X Flare as Famous Active... (2024 May 28)
Replies: 16
Views: 821

Re: APOD: Solar X Flare as Famous Active... (2024 May 28)

So, I presume this extremely brief flash at the 2s mark (approximately) is the flare? A split second later it vanishes. huge sp;ar f;lare from AR3664.jpg Also, I also assume the reason it won't have much of an effect on the Earth is simply because it wasn't directed in the Earth's direction? It loo...
by johnnydeep
Tue May 28, 2024 4:36 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 590

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

mjsakers wrote: Tue May 28, 2024 3:17 pm I'm interested in the name of the distant galaxy seen to the right of the cloud in the photo (?)
You mean the tiny one on a direct horizonal line rightward from the brightest star in the center of the blue region? I have no idea. But someone here might!
by johnnydeep
Tue May 28, 2024 3:43 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Solar X Flare as Famous Active... (2024 May 28)
Replies: 16
Views: 821

Re: APOD: Solar X Flare as Famous Active... (2024 May 28)

So, I presume this extremely brief flash at the 2s mark (approximately) is the flare? A split second later it vanishes. huge sp;ar f;lare from AR3664.jpg Also, I also assume the reason it won't have much of an effect on the Earth is simply because it wasn't directed in the Earth's direction? It look...
by johnnydeep
Mon May 27, 2024 6:52 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 590

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

They lie a mere 650 light-years away , at the boundary of the local bubble and the Chamaeleon molecular cloud complex. The orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees....
by johnnydeep
Mon May 27, 2024 6:06 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Chamaeleon I Molecular Cloud (2024 May 27)
Replies: 10
Views: 590

Re: APOD: Chamaeleon I Molecular Cloud (2024 May 27)

They lie a mere 650 light-years away , at the boundary of the local bubble and the Chamaeleon molecular cloud complex. The orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees....
by johnnydeep
Sun May 26, 2024 3:23 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Manicouagan Impact Crater from Space (2024 May 25)
Replies: 14
Views: 913

Re: APOD: Manicouagan Impact Crater from Space (2024 May 25)

Does anyone else see two additional spots that look like they could also be impact locations? Immediately to the Northwest of the circle for Manicouagan is another smaller circular object and even further northwest is a much larger circular object with a circle in its center. Are these all known to...
by johnnydeep
Sun May 26, 2024 3:15 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Solar Filament Erupts (2024 May 26)
Replies: 13
Views: 463

Re: APOD: A Solar Filament Erupts (2024 May 26)

I'll only add that "the resulting explosion shot electrons and ions into the Solar System, some of which arrived at Earth three days later" means those electrons and ions were moving at about 1,300,000 mph! (That's 93,000,000 miles / 3 days / 24 hours.)
by johnnydeep
Sat May 25, 2024 6:05 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Manicouagan Impact Crater from Space (2024 May 25)
Replies: 14
Views: 913

Re: APOD: Manicouagan Impact Crater from Space (2024 May 25)

The Siberian Traps, I'm just saying!!! :shock: ... I think I've heard that this enormously prolonged series of volcanic eruptions had something to do with the breaking up of with the super-continent Pangea and/or with the Indian tectonic plate colliding with the Russian plate. So the Permian–Triass...
by johnnydeep
Sat May 25, 2024 5:31 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Manicouagan Impact Crater from Space (2024 May 25)
Replies: 14
Views: 913

Re: APOD: Manicouagan Impact Crater from Space (2024 May 25)

Lots of interesting questions arise! How accurate are age estimates? The text says 215 million years, 1 million years plus or minus, so cannot have caused Triassic-Jurassic die-off at 201 million years. Percentage of error possible at that remove, for each estimate? Also, where was Quebec back then...
by johnnydeep
Fri May 24, 2024 1:12 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: M78 from the Euclid Space Telescope (2024 May 24)
Replies: 10
Views: 706

Re: APOD: M78 from the Euclid Space Telescope (2024 May 24)

The brightest foreground stars show six straight diffaction spikes and also at least two arcs. Are the arcs similarly an artefact of the way the telescope's mirror is mounted? You beat me to asking about the arcs. Clearly it's an optical artifact, but what causes it and why is it only visible on so...
by johnnydeep
Thu May 23, 2024 8:19 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 393

Re: APOD: Unraveling NGC 3169 (2024 May 23)

So, I'm reading that tiny NGC 3165 is also part of this triple, and at about the same distance, yet it doesn't seem to be interacting with the other two at all, either currently or in the past. Why not? First, these interactions are tidal . That means they occur when extended bodies are close enoug...
by johnnydeep
Thu May 23, 2024 8:18 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 393

Re: APOD: Unraveling NGC 3169 (2024 May 23)

So, I'm reading that tiny NGC 3165 is also part of this triple, and at about the same distance, yet it doesn't seem to be interacting with the other two at all, either currently or in the past. Why not? Also, I note that NGC 3165 is classified as a spiral too, which would confirm that spirals reall...
by johnnydeep
Thu May 23, 2024 6:43 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Unraveling NGC 3169 (2024 May 23)
Replies: 11
Views: 393

Re: APOD: Unraveling NGC 3169 (2024 May 23)

So, I'm reading that tiny NGC 3165 is also part of this triple, and at about the same distance, yet it doesn't seem to be interacting with the other two at all, either currently or in the past. Why not? Also, I note that NGC 3165 is classified as a spiral too, which would confirm that spirals really...
by johnnydeep
Mon May 20, 2024 1:01 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Jupiter Diving (2024 May 19)
Replies: 10
Views: 392

Re: APOD: Jupiter Diving (2024 May 19)

Chris Peterson wrote: Sun May 19, 2024 10:13 pm I just re-read Clarke's 1971 short story A Meeting with Medusa about a dirigible pilot who ventures down into the upper levels of Jupiter's atmosphere (and discovers life there). Kind of like the APOD, but in slow motion.
Nice. I'll have to go read it myself. For the first time!
by johnnydeep
Sun May 19, 2024 5:58 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Jupiter Diving (2024 May 19)
Replies: 10
Views: 392

Re: APOD: Jupiter Diving (2024 May 19)

Nice, but I want my gargantuan tentacled buoyant Jovian alien gas bag "jellyfish"!
by johnnydeep
Sat May 18, 2024 12:58 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: North Celestial Aurora (2024 May 18)
Replies: 1
Views: 319

Re: APOD: North Celestial Aurora (2024 May 18)

I trust we are nearing the end of Aurora Week! How about we have a Galaxy Week next?

EDIT: looking back, I see we had a cluster featured last Tuesday (May 14), so it wasn't a pure Aurora Week after all.