Starship Asterisk*

Ok. Presumably the chirp wave at the end marks the moment when the two black holes became one? Does there exist a theory / model explaining the general shape of this chirp? It would be nice to say that "this is what GR predicted the fusion of two black holes to sound like (on the GW spectrum) :...

Thanks for the extra bits, Chris and Bystander. Looks like I need to recalibrate my impression of what Kepler can detect. Let us also recall this older APOD. In particular what Chris said about Kepler's ability to measure differences in luminosity.

I like Jyrki's thought experiment. If it requires three (complete) periods, Jupiter verification would have had to start when I was born in 79.. Three transits = 2+ orbits = 2.5 (complete) periods on average. Are you seriously saying that three transits (obviously the minimum) is enough? No room le...

An interesting video. The observed exoplanets all seem to have relatively short orbital periods (in our Solar system -centric scale). I guess this is out of necessity... A thought experiment: Somebody far out there wants to detect Jupiter using Kepler's method. Jupiter's diameter is one tenth of the...

Joining the chorus of people thanking Chris for that extra bit of information. But that leads to my question. The biggest black blob of a planet is quite massive. I may have read too much sci-fi, but is it not so that a gas giant a couple orders of magnitude bigger than our own Jove is in danger of ...

Can we count on it being reported here on APOD, if they manage to free Spirit? Or should I just keep on checking the mission www-pages periodically for details?

Best of luck to "free the Spirit" -efforts !!!!!!!!!!!!!!

Cheers,

Jyrki

Googling for more information confirmed my recollection that in these parts it is spelled Betelgeuze. If I find an explanation for the variations in spelling I will return to this theme. In case somebody is interested; A web dictionary that I managed to find suggests that it is spelled with an 's' ...

Hey Art! If this astronomy thing doesn't pay the bills you can embark on an alternative career writing lyrics :-) Wouldn't it really be something to see it pop in our time! Then the fourth millenium astronomy books would show images of the remaining nebula not unlike the crab nebula, and insert witt...

Wow, you guys (Art in particular) have a large amount of data at your fingertips. That is one of the reasons I keep asking these questions :-) While we are at it I would like to follow up with another question. How closely is spherical shape correlated with a molten center (assuming solid celestial ...

Yup. That piece of rock looks a lot like the worn out metal ball that I used for shot put practice in my long gone junior days. This would be kind of new with half the paint still on, and the welder's seam on the equator still not smoothened out. If that impact crater is 450 km across, then this is ...

Since I am not shy about exposing my ignorance, and too proud of my ability for mental arithmetic I'll bite. After all, here is a chance to learn something! After wiggling the picture in my mind for a while I have "almost" convinced myself that the ship is mostly fighting the speed of Eart...

This distant echo made me think along other kind of loose lines. How likely it is that we are (or once where) inside a cloud of explosion like this one (dissipated long time ago)? Try to make sense out of that in whichever way you find appropriate :-). I have gotten something published on things cal...

Art! Thank you so much for the explanation of the spirals. To me they always seemed to be in violation of Kepler's law :-) My misunderstanding was, of course, that I thought the spiral arms to have originally looked like spokes on a wheel that became spiral due to varying rotational speeds. Silly of...

To Case: Thanks for the remarks and for the data on the luminosity of these stars. Yes, for more accurate figures I should use a spherical region, *but* I should also use the densest 3D packing (that you get when you pile up identical size balls in hexagonally packed layers appropriately interlaced ...

I have always wondered what the night time sky would look like, if we were in orbit about a member of a cluster as opposed to good ole Sol. Today's APOD finally gives me some raw data to do the math. Let's see. An angle slightly larger than that of the Moon at 800 lys. The Moon's diameter is about 3...

Just a point of information about SBX accuracy it is fire control system designed to guide kinetic kill weapons to multimach warheads. It is exactly what you would use for a satellite intercept. I'm not saying it was, just that it can. In that case I hope that they have fixed the bug that nearly ca...

But shouldn't all the debris re-collide over the Arctic, again and again and again? To me this sounds unlikely in the extreme. The orbits of the various left over pieces of debris will meet again at the starting point, but as they started their respective journeys around the globe at slightly diffe...

I'm not sure that gravitational redshift has been observed outside the laboratory. Hmm. This rings a bell (a bit late I'm afraid). I vaguely recall an exercise I encountered from somewhere. Possibly Misner,Thorne&Wheeler (never made through much of it - didn't feel comfortable with the math so ...

Thanks for the explanations to you all. To Art: I was thinking more like distant quasars rather than giants in our own Milky Way. I should have made that clear, sorry! To Chris: Thanks for the explanation. I was following the redshift link and realized that on the cosmological scale they mean someth...

http://apod.nasa.gov/apod/ap090104.html Hi All, My first post here.Background: PhD in math, theoretical physics minor as an undergrad, part-time work at Uni, part time in telecommunications industry. This is probably common knowledge to all the folks here, but since the point is never discussed in p...