Search found 17363 matches
- Sun Apr 28, 2024 4:09 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rings Around the Ring Nebula (2024 Apr 28)
- Replies: 11
- Views: 298
Re: APOD: Rings Around the Ring Nebula (2024 Apr 28)
So, something similar will likely be the fate of our own Sun, correct? From the link - Planetary Nebulae Planetary nebulae (PN) represent the last stages of evolution for low- and intermediate-mass stars whose Main Sequence mass was less than about 8 solar masses. After evolving through the Asympto...
- Sun Apr 28, 2024 3:06 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rings Around the Ring Nebula (2024 Apr 28)
- Replies: 11
- Views: 298
Re: APOD: Rings Around the Ring Nebula (2024 Apr 28)
Interesting adjective "elongated". Implies ovoid, but outermost wisps are almost perfectly circular. We do not know the viewing aspect. Could be looking down the barrel of somethig like the butterfly nebula. In fact, we understand both the viewing aspect and the 3D structure of the Ring N...
- Sun Apr 28, 2024 2:29 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rings Around the Ring Nebula (2024 Apr 28)
- Replies: 11
- Views: 298
Re: APOD: Rings Around the Ring Nebula (2024 Apr 28)
The instruments of the observers of the 16th and 17th centuries were less precise than the 150 mm amateur telescopes, but with the desire to discover they solved it. When the Ring Nebula is observed with an amateur telescope, a milky circle appears to the eye with a dark center and nothing more res...
- Sun Apr 28, 2024 2:20 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rings Around the Ring Nebula (2024 Apr 28)
- Replies: 11
- Views: 298
Re: APOD: Rings Around the Ring Nebula (2024 Apr 28)
Had Messier discovered this planetary nebula with the same fine details seen here, I'm sure he would have ditched the term "planetary" nebula right away! We read over and over that it's a misnomer; what would be a better term? Red giant remnant? I've always liked the term, and wouldn't la...
- Sat Apr 27, 2024 7:51 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: All Sky Moon Shadow (2024 Apr 27)
- Replies: 12
- Views: 319
Re: APOD: All Sky Moon Shadow (2024 Apr 27)
This image really showcases just how tiny this phenomenon really looks to the unaided eye. Still, though, it's a great image! Actually, to the unaided eye, it looks much larger. What this picture illustrates is just how small it actually is, despite the powerful illusion of it appearing much larger...
- Sat Apr 27, 2024 3:13 pm
- Forum: The Asterisk Café: Discuss Anything Astronomy Related
- Topic: Colors of Twilight vs. Sunset/Sunrise
- Replies: 28
- Views: 1921
Re: Colors of Twilight vs. Sunset/Sunrise
Thanks for the suggestion, Chris, I didn't think of that! :D 🐐 That's a lovely goat, by the way. What's her name? She looks very feminine to me! :D 👱🏾♀️ Ann Gretel. She'll be kidding in a couple of weeks. Thanks for teaching me a new word, Chris! I only knew one meaning of the word "kidding&q...
- Sat Apr 27, 2024 3:05 pm
- Forum: Open Space: Discuss Anything
- Topic: Weather!
- Replies: 2850
- Views: 987795
- Fri Apr 26, 2024 2:13 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
- Replies: 13
- Views: 565
Re: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
Well I was going to ask at what point we differentiate between a star cluster and dwarf spheroidal galaxy, but thanks to the color commentary I am guessing the black hole at the center may be a factor. :idea: Some globular clusters have central black holes. I think there are at least two difference...
- Fri Apr 26, 2024 1:58 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
- Replies: 13
- Views: 565
Re: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
So many unanswered questions - flabbergast to the max. First - what mechanism causes a star to rotate at such an enormous rate? Sucking gas off another star won’t do it. Second - try tracking down the two assertions about LEO I. Central density comes from a model which requires a central black hole...
- Fri Apr 26, 2024 12:55 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
- Replies: 13
- Views: 565
Re: APOD: Regulus and the Dwarf Galaxy (2024 Apr 26)
Well I was going to ask at what point we differentiate between a star cluster and dwarf spheroidal galaxy, but thanks to the color commentary I am guessing the black hole at the center may be a factor. :idea: Some globular clusters have central black holes. I think there are at least two difference...
- Thu Apr 25, 2024 3:55 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 604: Giant Stellar Nursery (2024 Apr 25)
- Replies: 7
- Views: 439
Re: APOD: NGC 604: Giant Stellar Nursery (2024 Apr 25)
I'm still somewhat puzzled by JWST colour choices. Is there a scientific reason why they chose pink/red for NGC 604 but a kind of rusty brownish not-really-red for the Tarantula Nebula? Is it to reflect different molecular properties or are these different colours for no real reason? 604.png 2070.j...
- Thu Apr 25, 2024 2:54 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: NGC 604: Giant Stellar Nursery (2024 Apr 25)
- Replies: 7
- Views: 439
Re: APOD: NGC 604: Giant Stellar Nursery (2024 Apr 25)
I'm still somewhat puzzled by JWST colour choices. Is there a scientific reason why they chose pink/red for NGC 604 but a kind of rusty brownish not-really-red for the Tarantula Nebula? Is it to reflect different molecular properties or are these different colours for no real reason? 604.png 2070.j...
- Tue Apr 23, 2024 6:12 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Contrail Shadow X (2024 Apr 23)
- Replies: 20
- Views: 577
Re: APOD: Contrail Shadow X (2024 Apr 23)
They are most certainly the condensation trails produced by passing jet airplanes. Contrails.P. Mitchell wrote: ↑Tue Apr 23, 2024 6:08 pm These are not 'contrails'.
- Tue Apr 23, 2024 3:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Contrail Shadow X (2024 Apr 23)
- Replies: 20
- Views: 577
Re: APOD: Contrail Shadow X (2024 Apr 23)
from beneath https://www.globe.gov/documents/16792331/47233527/cld_pers1.jpg/f3c94d07-4a38-414c-b856-1566e7e7c5ae?t=1581356571539 Right... but relevance to my comments? ok I am fitting the shadow, the trails and Sun… and you are right, Sun is high in the sky Contrail Shadow X (2024 Apr 23)-.jpg I'm...
- Tue Apr 23, 2024 2:27 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Contrail Shadow X (2024 Apr 23)
- Replies: 20
- Views: 577
Re: APOD: Contrail Shadow X (2024 Apr 23)
I agree with others here that we are seeing the shadows of the contrails cast down onto the clouds, not up. (I'm not convinced it's even possible to have a contrail shadow cast up onto a cloud... the Sun would have to be on or slightly below the horizon, and I think the directly illuminated cloud w...
- Tue Apr 23, 2024 1:49 pm
- Forum: The Observation Deck: Latest Sky Photography
- Topic: Submissions: 2024 April
- Replies: 96
- Views: 3816
Re: Submissions: 2024 April
NGC 2403 This spiral galaxy in Camelopardalis is often compared to M33, but is imaged much less often. Visually, it is a bright binocular object. It is strikingly populated by H II regions, one of which is so large it has its own catalog designation (NGC 2404) inside its parent galaxy. NGC 2403 is ...
- Tue Apr 23, 2024 12:53 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Contrail Shadow X (2024 Apr 23)
- Replies: 20
- Views: 577
Re: APOD: Contrail Shadow X (2024 Apr 23)
I agree with others here that we are seeing the shadows of the contrails cast down onto the clouds, not up. (I'm not convinced it's even possible to have a contrail shadow cast up onto a cloud... the Sun would have to be on or slightly below the horizon, and I think the directly illuminated cloud wo...
- Mon Apr 22, 2024 3:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Moon and Smoke Rings from Mt. Etna (2024 Apr 22)
- Replies: 6
- Views: 421
- Sun Apr 21, 2024 4:31 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
- Replies: 15
- Views: 546
Re: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
https://www.jpl.nasa.gov/news/press_kit ... pacecraft/johnnydeep wrote: ↑Sun Apr 21, 2024 4:25 pm Two questions about some info from the links:
1. Why does the Jove probe spin - stability I guess? But doesn't that negatively impact the ability to take pictures? And how fast is it spinning?
- Sun Apr 21, 2024 1:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
- Replies: 15
- Views: 546
Re: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
Until you recognize that Holst was addressing astrology, not astronomy!
- Sun Apr 21, 2024 1:08 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
- Replies: 15
- Views: 546
Re: APOD: Perijove 16: Passing Jupiter (2024 Apr 21)
1) it would have been nice to state the date rather than say it was the 16th pass…like that tells us anything. 2) on a personal note, I hate when people add music to space videos. Could really do better with the William Tell Overture instead of that squirrel music. The APODs focus on the “ oh, Wow!...
- Sun Apr 21, 2024 3:46 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Diamonds in the Sky (2024 Apr 20)
- Replies: 13
- Views: 568
Re: APOD: Diamonds in the Sky (2024 Apr 20)
Hey there, I'm the author of this composite. These images were captured with my lens on a star tracker in Arkansas. The camera was not level at the time of the exposures because I didn't make any adjustments to the camera during tracking by adjusting where the camera was on the right ascension axis...
- Sat Apr 20, 2024 3:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Diamonds in the Sky (2024 Apr 20)
- Replies: 13
- Views: 568
Re: APOD: Diamonds in the Sky (2024 Apr 20)
Alright, I'll ask: why aren't the two "diamonds" on the same line through the center of the eclipse? The centers of the Sun and Moon are coincident at totality, so why aren't the two diamond colinear with the center? The centers of the two bodies are only coincident at mid-totality if you...
- Thu Apr 18, 2024 6:02 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Total Eclipse and Comets (2024 Apr 17)
- Replies: 25
- Views: 1041
Re: APOD: Total Eclipse and Comets (2024 Apr 17)
But I suppose even if there are only two bodies in a system, like, say, the Sun and Jupiter, the Sun may - and will - change mass over time through its evolution along the Hertzsprung-Russell diagram due to changes in its nuclear fusion processes. So I'd think that could also eventually perturb Jup...
- Thu Apr 18, 2024 3:46 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Total Eclipse and Comets (2024 Apr 17)
- Replies: 25
- Views: 1041
Re: APOD: Total Eclipse and Comets (2024 Apr 17)
I wonder what makes the comet get too close to the Sun ? I'd imagine gravity pull .. but then, how long it must have taken that comet to reach that stage (i mean how many times it must have made rounds around Sun and how many years it must have been doing it before finally getting too close and get...