Search found 2891 matches
- Tue May 07, 2024 6:52 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Black Hole Accreting with Jet (2024 May 07)
- Replies: 15
- Views: 424
Re: APOD: Black Hole Accreting with Jet (2024 May 07)
From the link posted just above: "You can roughly think of a black hole as a star that traps all of its light" . I like the " its " light. We normally read that "even light" can't escape a black hole, but saying "its" own light makes me wonder further. For in...
- Mon May 06, 2024 6:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Total Solar Eclipse from Sliver to... (2024 May 06)
- Replies: 4
- Views: 286
Re: APOD: A Total Solar Eclipse from Sliver to... (2024 May 06)
Nice to see the diamonds of the two rings on diametrically opposite sides through the center, as god intended. (Yeah, I know Chris has pointed out that it might not appear like this in other totality locations.)
- Sun May 05, 2024 4:47 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
- Replies: 29
- Views: 680
Re: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
A black hole's "gravitational effect" is determined by its mass. The event horizon isn't a real thing, just a boundary that defines where light can't escape. It really has little physical meaning. We're talking here about stellar mass black holes interacting with stars . That is, objects ...
- Sun May 05, 2024 4:36 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
- Replies: 29
- Views: 680
Re: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
The mass of the black hole doesn't matter, except to the extent that it's a factor in determining the orbit. Whether it hits the star depends on whether its orbit intersects the interior of the star. This is basically no different than two stars passing by each other, except in the case of the blac...
- Sun May 05, 2024 4:06 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
- Replies: 29
- Views: 680
Re: APOD: A Black Hole Disrupts a Passing Star (2024 May 05)
The tidal force of a black hole, because it is so small, is also small. Something doesn't feel tidal distortion around a black hole until it's about to fall in. (And with supermassive black holes, after it's fallen past the event horizon.) I edited my post with more queries... The mass of the black...
- Sat May 04, 2024 8:18 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: 3 ATs (2024 May 04)
- Replies: 5
- Views: 321
Re: APOD: 3 ATs (2024 May 04)
The 3ATs are certainly an advantage for us who keep on looking for new pictures of the infinity of the Cosmos. It is also fascinating that our beautiful Earth will not be destroyed but only be transformed into a New Earth just like other planets like Mars to be terraformed. Well, your title certain...
- Sat May 04, 2024 4:07 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: 3 ATs (2024 May 04)
- Replies: 5
- Views: 321
Re: APOD: 3 ATs (2024 May 04)
I searched in vain on the ESO site for an annotated overall map of the VLTI facility but came up empty. But google was my friend. Sadly though, the - much! - smaller R2D2-like ATs on their tracks aren't labeled, but are clear to see in the lower parts of the photo: https://www.eso.org/sci/facilities...
- Sat May 04, 2024 12:50 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Well. When I look at the galaxy in IR, it doesn't remind me much of a bar either. ...more like an alien.... :evil: https://live.staticflickr.com/65535/52800764387_d5f66eb24a_c.jpg Image source: SST ... https://live.staticflickr.com/65535/52801748535_57b2c13737_b.jpg Image source: HST jac berne (fli...
- Fri May 03, 2024 10:07 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Temperatures on Exoplanet WASP-43b (2024 May 03)
- Replies: 25
- Views: 624
Re: APOD: Temperatures on Exoplanet WASP-43b (2024 May 03)
I find it interesting that the trailing side is slightly hotter than the leading side. That's what I was wondering. If the planet was rocky, I suppose the temp would be similar to it's present state, except that it would take longer to go from sun-side to dark-side? But that is I guess a moot point...
- Fri May 03, 2024 10:06 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Temperatures on Exoplanet WASP-43b (2024 May 03)
- Replies: 25
- Views: 624
Re: APOD: Temperatures on Exoplanet WASP-43b (2024 May 03)
The last link says the winds are 5,000 mph!wilddouglascounty wrote: ↑Fri May 03, 2024 8:03 pm Seems like the winds must be unreal on such a system, and judging from the heat retention, the atmosphere pretty darn thick. It would be interesting for someone to make a stab at modeling such extreme conditions!
- Fri May 03, 2024 7:46 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
I just told you that I don't necessarily always trust Wikipedia, but now I'm going to quote Wikipedia anyway to back up my claim that there are two bars in NGC 1365: And I can see the bars of NGC 1365. :wink: Ann Is there even a definition of a "bar" based on something other than mere app...
- Fri May 03, 2024 3:19 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
I just told you that I don't necessarily always trust Wikipedia, but now I'm going to quote Wikipedia anyway to back up my claim that there are two bars in NGC 1365: And I can see the bars of NGC 1365. :wink: Ann Is there even a definition of a "bar" based on something other than mere app...
- Fri May 03, 2024 2:17 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Still not much of a definitive bar in M61 at all compared to your other examples. And I'm not convinced of the "inner" bar in NGC 1365 either! "A bar is in the eye of the beholder" it seems. I just told you that I don't necessarily always trust Wikipedia, but now I'm going to qu...
- Fri May 03, 2024 11:46 am
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Let's look at a truly barred galaxy, M61: Wikipedia thinks M61 is an intermediate barred spiral: Messier 61 (also known as M61, NGC 4303, or the Swelling Spiral Galaxy) is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779...
- Thu May 02, 2024 9:09 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Let's look at a truly barred galaxy, M61: Wikipedia thinks M61 is an intermediate barred spiral: Messier 61 (also known as M61, NGC 4303, or the Swelling Spiral Galaxy) is an intermediate barred spiral galaxy in the Virgo Cluster of galaxies. It was first discovered by Barnaba Oriani on May 5, 1779...
- Thu May 02, 2024 4:39 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Sadly, this "One of the brightest members of the Virgo Cluster of galaxies, M100, also known as NGC 4321" is not even shown at the Virgo Cluster APOD link:
- Thu May 02, 2024 3:10 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
- Replies: 24
- Views: 717
Re: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
Well, yes... not really an option with most astronomical objects, though! Angular sizes are usually only given when they are interesting in their own right for some reason (like if an object is the apparent size of the Moon). But they are always easily determined in any image with more than a handf...
- Thu May 02, 2024 1:26 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
- Replies: 34
- Views: 881
Re: APOD: M100: A Grand Design Spiral Galaxy (2024 May 02)
Thank you very much. Extremely honored again. 🙏🏼 I am blessed with Bortle 2 skies in Northern Arizona. -Drew https://www.astrobin.com/users/DrewJEvans/ https://NAZObservatory.com Excellent work! Can I ask how many hours did you spend creating this picture in total? The link to the author's Astrobin...
- Thu May 02, 2024 1:15 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
- Replies: 24
- Views: 717
Re: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
But in order to determine that the snowman is 2 meters high, we need to know our distance from it and the angle it subtends at that distance. Likewise for the nebula. ... I was declaring the Snowman's height, not estimating. Well, yes... not really an option with most astronomical objects, though! ...
- Wed May 01, 2024 5:44 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
- Replies: 24
- Views: 717
Re: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
Just wanted to note that there are two possible right angle triangles that could be used to determine the distance and angle, but at the large distances typically involved, they are almost the same. I had always assumed that we were using the smaller ɑ angle, but it's really the slightly larger angl...
- Wed May 01, 2024 4:59 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
- Replies: 24
- Views: 717
Re: APOD: IC 1795: The Fishhead Nebula (2024 May 01)
In context from a wider field of view image at one of the links in the text:
- Tue Apr 30, 2024 9:31 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
- Replies: 16
- Views: 830
Re: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
Not so with supernovas. And it's fascinating to think that supernovas type Ia form in much the same way as cataclysmic novas like GK Per. The difference is that so much matter builds up on the white dwarf's surface that the white dwarf reaches its Chandrasekhar limit, the maximum mass of a white dw...
- Tue Apr 30, 2024 6:31 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
- Replies: 16
- Views: 830
Re: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
Sort of. Here's a succession of images taken over the years that demonstrate the growth: https://vimeo.com/31120259mason dixon wrote: ↑Tue Apr 30, 2024 6:19 pm Is there a timelapse of the Firework nebula growing in size like the Crab nebula?
- Tue Apr 30, 2024 1:09 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
- Replies: 16
- Views: 830
Re: APOD: GK Per: Nova and Planetary Nebula (2024 Apr 30)
Not so with supernovas. And it's fascinating to think that supernovas type Ia form in much the same way as cataclysmic novas like GK Per. The difference is that so much matter builds up on the white dwarf's surface that the white dwarf reaches its Chandrasekhar limit, the maximum mass of a white dw...
- Mon Apr 29, 2024 10:35 pm
- Forum: The Bridge: Discuss an Astronomy Picture of the Day
- Topic: APOD: Rings Around the Ring Nebula (2024 Apr 28)
- Replies: 15
- Views: 615
Re: APOD: Rings Around the Ring Nebula (2024 Apr 28)
Ok, agreed. The Sun would be merely senescent, but not yet entirely dead! 😊 Maybe these stars are quite comfortable in anticipation; a ripening chrysalis perhaps. The ripening is only beginning, give them a quadrillion years and white dwarfs apparently turn into giant diamonds! Which of course are ...