Starship Asterisk*

I suppose the Sun has no meaningfully permanent longitude map that would allow these two coronal un-wrappings to be matched up. Which makes sense since the Sun is just a ball of plasma! But I gather that the rotational north-south pole line should remain the same long term. Or does it? I know the r...

I suppose the Sun has no meaningfully permanent longitude map that would allow these two coronal un-wrappings to be matched up. Which makes sense since the Sun is just a ball of plasma! But I gather that the rotational north-south pole line should remain the same long term. Or does it? I know the ro...

Some random comments: .... - And finally, Ann, what exactly is a "color commentator" (though I suppose that is obvious) and how did you acquire that title? (After two years here, I figure I'd ask. 😊) Well, the title was given to me soon after I joined Starship Asterisk* in 2010 (before we...

Some random comments: - Is it just my imagination or does the central star look like it's at the center of a cluster of stars? (Answer: probably I'm being misled by the radiating gas/dust lines). - So, I gather that WD J005311 ("the hottest star known") is the "zombie star". - It...

Are different, despite the appearance after all the directions light travels have been distorted. That's my understanding. Ok. My brain doesn't see it yet. Oh, and what of the nice symmetrical depiction of the magnetic field lines we see here: would it also look the same from any POV? (I may have m...

To be clear, the geometry of the accretion disk and of the magnetic field changes with orientation. It's just a product of the extreme curvature of space around the black hole that the appearance doesn't change much. So the accretion disk "looks" the same from any POV, yet the geometry of...

I can't answer as to what the field looks like. But as noted above, the accretion disk looks similar from most observation directions, and we don't really know what the inclination of Sgr A* even is. Best estimate is inclined 60° to the galaxy or 30° to the ecliptic, but there's a range of tens of ...

Minor nit. The lines indicate polarization of electromagnetic radiation. This is most likely a proxy for magnetic fields. So if the accretion disk can be seen perpendicularly to the line of sight from any angle (as other posts of videos point out), and we're viewing the magnetic field lines in the ...

I have nothing to say about the magnetic lines in today's APOD, but there is a video that explains why the black hole images (minus the magnetic lines) look the way they do. Minor nit. The lines indicate polarization of electromagnetic radiation. This is most likely a proxy for magnetic fields. So ...

Steen Thomsen wrote: ↑Sun Mar 31, 2024 11:05 am Tycho Brahe was certainly a nobleman, but he had no 'de' or 'von' or 'af' in his name.
Best regards from his grand-10-nephew
Steen Thomsen

Yup. That leapt out to me as well.

... Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate , deposited by evaporating water that emerged from within. Sulfuric acid hydrate is another possible explanation for the contaminant observed spectro...

I can hardly wait the 6 more years for Europa Clipper to arrive at Jupiter! (Assuming it launches ok in October.)

Any educated speculation about the cause of the rusty coloration of the long, curving fractures? ... Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate , deposited by evaporating water that emerged from w...

I am not. I'm suggesting that "leftover galaxy core" is a lousy term for it, and that it isn't even a globular cluster, except visually. My point is that there's no evidence that globular clusters (plural, in general) are "leftover galaxy cores". Ok, but it seems the paper is ar...

What of it? Well, doesn't it say that Omega Centauri is - or very well could be - the remnant core of a cannibalized galaxy? And aren't you arguing that it's not? I am not. I'm suggesting that "leftover galaxy core" is a lousy term for it, and that it isn't even a globular cluster, except...

I would not characterize the remnant of a collision as a "leftover galaxy core"! In any case, the hypothesis that Omega Centauri isn't a "true" globular cluster, but rather something left from a collision, is based on the observation that its stellar population looks very differ...

There is no evidence that globular clusters are "leftover galaxy cores". I take it that there is some evidence that Omega Centauri is? Ann I would not characterize the remnant of a collision as a "leftover galaxy core"! In any case, the hypothesis that Omega Centauri isn't a &qu...

Beautiful and Amazing. I wish they had mentioned the range of distances to galaxies (e.g. from 170 million to 10 billion light years away etc). Just to get and give a perspective, not everything that's "seen (looks) together and close" isn't so in reality. Given that the diameter of the c...

Sure, this is creative I suppose, but for me it does absolutely nothing to "help [this] listeners appreciate and understand a visual image of a supernova remnant".

For a shadow, the umbra is the area from which you cannot see any of the source, and the penumbra is the area where you can see part of the source. The smaller the (angular) size of the light source compared with the shadowing body, the more of the shadow is umbral. For a point source light, there ...

Can anyone explain why the edges of the Moon's shadow on the Earth are so blurry, while the outline of Io's shadow on Jupiter is so sharp? For a shadow, the umbra is the area from which you cannot see any of the source, and the penumbra is the area where you can see part of the source. The smaller ...

I love a good Martian sci-fi story, too, featuring the incomparable Dejah Thoris, princess of Helium, and Tars Tarkas, Jeddak of Thark. But when humans get to Mars, it will probably be after we figure out how the UFOS do it. Here are the problems to consider: Gravity is 38% of Earth gravity. Atmosp...

https://apod.nasa.gov/apod/calendar/S_240323.jpg Ares 3 Landing Site: The Martian Revisited Explanation: This close-up from the Mars Reconnaissance Orbiter's HiRISE camera shows weathered craters and windblown deposits in southern Acidalia Planitia . A striking shade of blue in standard HiRISE imag...

Well, Tycho Brahe was the first astronomer to create a rich, very accurate catalog of astrometric positions, so it's logical that the catalog of Hipparcos observations should honor him. Alright, that makes sense. But that just begs another question: why is that mission called Hipparcos?! (Wikipedia...

From SIMBAD: I meant why is it the "Tycho" catalog as opposed to, say, the "Peterson" catalog?! Well, Tycho Brahe was the first astronomer to create a rich, very accurate catalog of astrometric positions, so it's logical that the catalog of Hipparcos observations should honor hi...