Starship Asterisk*

Astro_mark wrote: ↑Tue May 14, 2024 7:12 pm Indeed! I thought I was still commenting on the moons post that was one line before this one.
Of this image I love the natural colors of the sky and the orange glow of the horizon!

Sorry, but what moons post? Still not getting it. I must be getting too old...

That's because you have a cheap calculator. Mine has more digits, so I know the age of this cluster to within a few milliseconds! I actually rounded it down. The Windows Calc app gives me 11,668,096.170609625164708884885897 ! Cool. So we know the age of the cluster to within a few attoseconds! I lo...

What about it? The link to the "webda" page mentioned (https://webda.physics.muni.cz/cgi-bin/ocl_page.cgi?dirname=ngc2169) shows a "Log age" of 7.067 and 10 the power of that is about 11,668,096.17 😊 That's because you have a cheap calculator. Mine has more digits, so I know the...

Chris Peterson wrote: ↑Tue May 14, 2024 6:10 pm

Roy wrote: ↑Tue May 14, 2024 6:09 pmLog Age

What about it?

The link to the "webda" page mentioned (https://webda.physics.muni.cz/cgi-bin/o ... me=ngc2169) shows a "Log age" of 7.067 and 10 the power of that is about 11,668,096.17

EDIT: oops: Roy beat me to it!

Hopefully someone can clear up some sun confusions for me. Today's APOD shows AR-3664 towards the BOTTOM of the solar disk. That of May 11 showed this cluster to be towards the RIGHT. Does the apparent orientation of the sun shift from day to day? My understanding is that the storms move from left ...

Hi! I'd like to introduce myself, I'm Lee! I won't be contributing anything of value to these discussions. I just love to look at the pictures. As an example, the first thing I thought of when I saw this one was "ET phone home". So, there ya go! I do read the discussions and sometimes eve...

In its simplicity, this image is both artistic and scientific. the colors of the Moon catch the eye. I would like to understand a little more what the magenta color of the central moon is due to. I will check Marcella's blog. Perhaps it is a Moon low on the horizon with this coloration that the aut...

I wonder why after I clicked Show in YouTube I was presented with a view defaulted to 480 pixel height video and had to go through options to see 1080 pixel height original video Hmm, I get a 720p (1024x720) video resolution when I click on the link. I would think the default resolution is set by t...

Amazing display on Friday night from Cornwall in the South-West of the UK. The pillars were bright rapidly changing, in subtle greens, purples and occasionally blue. Didn't know where to look at times, there were some bright transient features due South. Brightest display here for over 20 years I b...

The result looks like so: https://www.youtube.com/watch?v=1MYJhsjX-C4 Thanks johnny, I had to strip a channel parameter off my url in order to get it to work. FYI, this URL also works properly in the [youtube][/youtube] tags: https://www.youtube.com/watch?v=1MYJhsjX-C4?si=zsBn6ckJw_SLulZa

Amazing display on Friday night from Cornwall in the South-West of the UK. The pillars were bright rapidly changing, in subtle greens, purples and occasionally blue. Didn't know where to look at times, there were some bright transient features due South. Brightest display here for over 20 years I b...

Is this image, its quality and the gesture to publish it, a huge joke? From time to time APOD editions pop into my view, last time I left some abrasive comments was for the photoshoped solar eclipse-moon-something. I literally shoot better (read: much better, link below to our forum) images during ...

The four CMEs in the last days, and the new one today, all came from this group, and are responsible for the current auroral activity. Ok. Is the cause and effect indisputable? I guess so simply due to travel time from the Sun and the extreme improbability of it NOT being so. The flares and ejectio...

Wrong question. Cause and effect. Where were the sunspots a couple of days ago? That's what mattered! And where were they? Is it ever possible to link a specific sunspot group with an aurora? The four CMEs in the last days, and the new one today, all came from this group, and are responsible for th...

Pretty good here in central Colorado, 38°N, despite it being pretty cloudy. This is an allsky video from late twilight to 1:30am when it completely clouded over. https://vimeo.com/945334892 Last image below was taken pointing very high, with the Big Dipper in the frame. _ E7_48521p.jpg E7_48527p.jp...

Pretty good here in central Colorado, 38°N, despite it being pretty cloudy. This is an allsky video from late twilight to 1:30am when it completely clouded over. https://vimeo.com/945334892 Last image below was taken pointing very high, with the Big Dipper in the frame. _ E7_48521p.jpg E7_48527p.jp...

Sunspot groups remind me of random Life patterns (as in Conway's cellular automaton "Game of Life"). Here's an illustrative example I just created with the very excellent "Golly" app: https://asterisk.apod.com/download/file.php?id=49682&t=1 But the location of sunspots on th...

Sunspot groups remind me of random Life patterns (as in Conway's cellular automaton "Game of Life"). Here's an illustrative example I just created with the very excellent "Golly" app: sunspot group life pattern.jpg And hey, the Sun's atmosphere is even partitioned into "cell...

Does a pair of BHs have to lose any of its total mass-energy to merge? Can the two BHs just get closer (losing potenial energy and gaining kinetic energy) and then merge in a central collision? It seems to me that a straight line collision would involve minimum of going around and radiating away on...

I don't think there are any missing words. When a mass is allowed to move in a gravitational field, its velocity increases, which represents a conversion of gravitational potential energy to kinetic energy. Right? And any accelerating mass generates gravitational waves ("acceleration" can...

In the mundane world, gravitational potential energy gets converted to kinetic energy, gets converted to gravitational waves all the time. Like when you drop a rock. But it takes something as massive as merging black holes or neutron stars to produce strong enough gravitational waves for our existi...

Neither black hole lost mass. The individual precursor black holes merged to form a new black hole, and it has a higher mass than either of the precursors. The total mass difference reflects the conversion of gravitational potential energy (as the two precursors got closer) into kinetic energy, and...

Hello everybody, I have a question about the BHs' masses. I imagined that nothing could escape from a BH (except perhaps by Hawking radiation) but it seems that part of the mass of a couple of merging BHs is radiated as GW. I suspect that the energy emitted as GW comes from the kinetic/gravitationa...

I don't think the quote is a good description at all. A black hole is an entity which is sufficiently dense that there is a region around it (bounded by the event horizon... which itself isn't a physical thing) where the escape velocity is greater than c. Really, that's all. Every visual aspect of ...

Photons are just packets of energy. Presumably the energy is converted to its mass form once a photon falls into a black hole. The black hole keeps its energy; it doesn't keep its "light". That implies a cool idea! All the photons of every star in the sky that reach a black hole are conti...