Starship Asterisk*

You have to wonder why the Moon's far side is so different from its near side. Does it have anything to do with the fact that the Moon is tidally locked, and always shows the same face to the Earth? Then again, the Earth itself also looks very different in different places.We don't often think of t...

Massive stars form from particularly large disks. It seems likely, at least to me, that large disks are more prone than smaller ones to fragmenting, thus creating massive stars that are born as binaries. Thanks Ann. But what causes this fragmentations? Gravity from a nearby star, or a black hole? O...

Is the source of the gas in prominent blue arc at the upper left the W-R star? Or is that just gas that happened to be in the vicinity? It's complicated. W-R stars blow off a lot of material which often generates a local nebula, similar in some ways to a planetary nebula. But they can certainly exi...

Is the source of the gas in prominent blue arc at the upper left the WR star? Or is that just gas that happened to be in the vicinity? It's complicated. W-R stars blow off a lot of material which often generates a local nebula, similar in some ways to a planetary nebula. But they can certainly exis...

Given that something like 85% of high mass stars are part of binary systems, maybe the question to ask is why only 50% of WR stars are binaries? OK, so I ask: Why 85% of high mass stars are part of binary systems? Probably because high-mass stars typically form in clusters, and the very high-mass s...

But why they occur in binary systems? And why their companion is most likely a compact object? Given that something like 85% of high mass stars are part of binary systems, maybe the question to ask is why only 50% of WR stars are binaries? OK, so I ask: Why 85% of high mass stars are part of binary...

It is estimated that about 50% of Wolf-Rayet stars occur in binary systems. Proposed companions are another Wolf-Rayet star, or a compact companion such as a black hole or neutron star. There is some evidence for both of these scenarios, but conclusive observations have yet to be obtained. The only...

a Wolf-Rayet nebula is primarily shaped by the tremendous heat and wind of its own central star Ann I have trouble getting my head wrapped round the way that things work on these scales. If the nebula has something like a 40 light year radius, does that mean that the glow from the nebula has actual...

I find it a little irritating that this APOD is so large that I have to post it here as an attachment! For reasons unclear the images are posted as PNG files. That's a totally inappropriate format in this case. If you want to use them in your response, you can simply open them in your favorite imag...

Chris, That is my suspicion as well. Only possible glitch is if some outfit has operations in both the EU and outside the EU (vis a vis a multi-national book publisher, media outfit etc) and where you could choose the venue to pursue the case. And how much you're willing to throw at lawyers. Always...

In instances were a physical person is involved, there is a statute of limitations and which I recall is 70 years after they pass away. It is for this reason that some well-known books are now in print by third-party publishers and available at steep discounts since the authors have died and did so...

The galaxy is not bent unless you distort the photo. The galaxy seen from within the disk is straight. This is improper to make laymen think this arch actually exists. These photos of bent Milky Ways are improper and shouldn’t be posted. If you are standing on the ground when the Milky Way is overh...

So I have been waiting to see photos taken from the ISS or any other orbiting spacecraft/satellite that shows the auroras of May 10-11 in color from space. I haven't run across a single such image and really don't know where to look for them. Does someone know where I can view such photos? I've see...

So, I presume this extremely brief flash at the 2s mark (approximately) is the flare? A split second later it vanishes. huge sp;ar f;lare from AR3664.jpg Also, I also assume the reason it won't have much of an effect on the Earth is simply because it wasn't directed in the Earth's direction? It loo...

So, I presume this extremely brief flash at the 2s mark (approximately) is the flare? A split second later it vanishes. huge sp;ar f;lare from AR3664.jpg Also, I also assume the reason it won't have much of an effect on the Earth is simply because it wasn't directed in the Earth's direction? It loo...

APOD, please, please, please, be more specific in description of each image! After spending 5+ minutes of my time, I could not find how this image was obtained - what tool, method or interpretation was used? I guess the picture is made in UV? References to NASA etc do not help! This is very importa...

If one is going to map grayscale to a color scale, why limit ourselves to just purple or orange, when we could have both? The perceptually uniform colormap "plasma" or "inferno" freely available from matplotlib might look really good, and they seem appropriately named. Yes, and ...

How about showing the UV Sun as purple? I don't understand those who say that it would be horribly wrong to show the UV Sun as purple, but OK to show it as orange. Here's another pseudocolor palette example, using today's Sun image. I think that, objectively, the palette they've chosen allows us to...

It's not my kind of image either, partly because I tend not to be all that enthusiastic about pictures of the Sun, but mostly because it really irks me that the Sun is shown as orange. The image appears to be constructed from a single channel of data made by selecting the brightest pixels in a stac...

It's not my kind of image either, partly because I tend not to be all that enthusiastic about pictures of the Sun, but mostly because it really irks me that the Sun is shown as orange. The image appears to be constructed from a single channel of data made by selecting the brightest pixels in a stac...

This occurred when there was only one landmass on Earth, Pangea. The area that became Quebec was at a lower latitude, probably not far north of the tropics. The radiometric dating methods used to determine the age of the event are very well developed, so the 215 million year determination is almost...

Lots of interesting questions arise! How accurate are age estimates? The text says 215 million years, 1 million years plus or minus, so cannot have caused Triassic-Jurassic die-off at 201 million years. Percentage of error possible at that remove, for each estimate? Also, where was Quebec back then...

Lots of interesting questions arise! How accurate are age estimates? The text says 215 million years, 1 million years plus or minus, so cannot have caused Triassic-Jurassic die-off at 201 million years. Percentage of error possible at that remove, for each estimate? Also, where was Quebec back then...

Orbiting 400 kilometers above Quebec, Canada, planet Earth, the International Space Station Expedition 59 crew captured this snapshot of the broad St. Lawrence River and curiously circular Lake Manicouagan on April 11. April 11? Which one? I guess the one in 2019? As Expedition 59 was from March th...

So, I'm reading that tiny NGC 3165 is also part of this triple, and at about the same distance, yet it doesn't seem to be interacting with the other two at all, either currently or in the past. Why not? First, these interactions are tidal . That means they occur when extended bodies are close enoug...