Starship Asterisk*

I made a mistake in my previous post so I will assume that caused a miscommunication. I have changed the previous post saying TV news people are reporting is fact to instead say TV news people are reporting it as fact . If the current findings persist as being fact then it is a fantastic developmen...

So the image resolved the area around the black hole on a scale below that expected for its event horizon. But that means that the event horizon is smaller than expected? Otherwise we wouldn't be able to see anything there? I'm also thinking of the extreme gravity near a supergiant black hole, and ...

RickyM wrote: ↑Thu Apr 11, 2019 6:59 pm The passage of the ISS at that date, time and location wasn't 7 minutes long

My checks indicate it was visible for about 7 minutes. On what do you base your assertion? For how long do you think it was visible?

I offer this:
https://www.nytimes.com/2007/10/28/opin ... 81659.html

Light that approaches a radius of about 2.5 or 2.6 times the radius of the event horizon, spirals inward and crosses the event horizon, never to be seen again. That's the explanation for the size of the shadow, as I understand it. Light that approaches a radius of about 1.5 times the radius of the ...

With M87 being 12 degrees north of the celestial equator, I am not sure how the South Pole Telescope might have helped in this image. Certainly useful for Sgr A*, however, the data from which, I assume, is currently being analysed. I am now wondering how a resolution of 20 micro arc seconds was ach...

With M87 being 12 degrees north of the celestial equator, I am not sure how the South Pole Telescope might have helped in this image. Certainly useful for Sgr A*, however, the data from which, I assume, is currently being analysed. I am now wondering how a resolution of 20 micro arc seconds was achi...

The thing I don't hear anyone talking about is why they had to get a black hole from more than 50 million light-years. Why can't they get an image of the (or a) black hole in our galaxy? If astronomers are unable to get an image of a black hole in our galaxy then how can they be sure that the image...

Nitpicker, not to bust bubbles but 'fake news' is an exploitation of the lowest common denominator. Try harder to rise above it, my friend. Martin, you have incorrectly attributed the words of "Confused" to me, by mangling the quote tags. It might be best to ease off on the condescension,...

So - are we seeing the effect of a very massive object on a rotating ball of gas? We are not actually seeing the black hole or the event horizon? I would like to see a proper physics explanation of the meaning of the image. We are seeing the effect of the black hole on the hot accretion disc surrou...

Iksarfighter wrote: ↑Thu Apr 11, 2019 8:02 am OK this black thing isn't the event horizon of the BH, but what would be the size of the event horizon of this BH compared to this image please ?

Smaller than the shadow by a factor of 2.5.

The thing I don't hear anyone talking about is why they had to get a black hole from more than 50 million light-years. Why can't they get an image of the (or a) black hole in our galaxy? If astronomers are unable to get an image of a black hole in our galaxy then how can they be sure that the image...

Heh, heh, 2.5 times smaller . :-) I agree that using "times" should be for multiplication, not as used there. A percent would be easy to understand, or even a fraction, if a whole number is the smaller measure (5 times smaller is easy to understand if written as 1/5th). My 1/50th of a dol...

The ESO video called it “superheated gas and dust”. Are we seeing (the bright parts of) the accretion disk here? Does such a disk go all the way up to the event horizon? Why is “the shadow” of the black hole not the same as event horizon? According to the "EHT" link in the last sentence o...

Thats awesome. But would it be being difficult to ask how it is that radio telescopes can 'see' or resolve such stuff, at the minute angles and immense distances that this is being observed at ? The angular resolution of a telescope array, in radians, is observed wavelength divided by baseline dist...

high frame rate digital camera. A total of 2500 frames were recorded during the 7 minute long visible ISS passage 5.95 fps is not a high frame rate. The recording probably didn't cover the full 7 minutes. I would be surprised to learn these individual images were made with exposure times longer tha...

Starship discussions are so wonderfully broad: grammarism, sizeism, timelapseism, ageism and goldfishism.

Re the timelapseism, it is possible that only a limited number of individual frames were recorded, so it was sped up to provide a smoother animation.

high frame rate digital camera. A total of 2500 frames were recorded during the 7 minute long visible ISS passage 5.95 fps is not a high frame rate. The recording probably didn't cover the full 7 minutes. I would be surprised to learn these individual images were made with exposure times longer tha...

I like the music in the "Moon moves in front" video link. It reminds me of the sound inside an MRI scanner, or perhaps a Berlin nightclub. Dark and full of panic ... perhaps reflective of the task of recording a fleeting occultation with multiple filters.

And never mind that Phobos actually has dimensions of 27×22×18 km ... its mean diameter of 22.5 km is 150 times smaller than Luna's.

I suppose a scientific paper might be written as "Phobos, at 1.15x10^4 meters across, is 6.67x10^-3 times the diameter of Luna". Quite revolting. I'm glad the APOD captions aren't written like scientific papers.

The phrase "150 times smaller than Luna" is not at all nonsensical. I suspect more people would have trouble understanding "1/150th the size of Luna". But I cannot say with any certainty whether either form is discouraged in any style guide. The phrase "50 times closer"...

And here is an improved version from the same 90 second video, created after a full night's sleep: I think the colour balance is a little more accurate in this version, and it is slightly sharper, especially at the north pole.

They relate to the degree of ionization of the nebula, which in turn is dependent on the temperature of (or distance from) the ionizing source. Ann No, the narrow bands relate to the specific elements in the nebula, that are being ionised by photons from nearby stars. Each different ionised element...

But, Ann, do the narrow bands of ionisation wavelengths relate to temperature in the same way as starlight? I think they rather relate to the elements being ionised. They relate to the degree of ionization of the nebula, which in turn is dependent on the temperature of (or distance from) the ionizi...