Folks, Some Birr publications are up for sale. Here's the list as I got it. The tables are lost without HTML, but I hope I made them legible. Clear skies,...
Les Cowley, who runs the best atmospheric optics page on the Web, has posted as his "optics picture of the day" a sequence of images from the Kitt Peak all-sky...
Brian Skiff
bas@...
Nov 2, 2008 6:36 pm
21741
Hi Brian, Thank you so much for passing this on! I have unknowingly recorded this phenomenon of gravity waves in the airglow on individual long-exposure images...
I suppose the next thing will be getting a sensitive color CCD under a fisheye lens. At least for those of us in Arizona and New Mexico, the Kitt Peak camera...
Brian Skiff
bas@...
Nov 3, 2008 6:19 pm
21743
... I've seen them from time to time. It takes a quiet night and excellent horizons. I have observed a many minute variation at the limit of observing, ...
Those of us who view at the limits of our scopes often notice that certain features, details, or stars themselves go in and out of visibility. Part of the...
One of the joys of Astronomy is the thought provoking nature of the hobby. I've been chewing on this particular line for some time now and it's ready to be...
... You seem to make two assumptions that might be closely scrutiny. 1) the SAC catalog faithfully reflects the universe 2) the universe is isotropic and...
I can confirm what Brian T and Mel say about catalogue incompleteness. Lists based on old catalogues such as the venerable Shapley-Ames galaxies are bound to...
Brian Skiff
bas@...
Nov 19, 2008 8:20 pm
21749
A few years back I got to thinking about the same subject. If the size of the Universe seen doubles in diameter, it increases a factor of 8 in volume. At...
... No, there would still be a selection bias. That's the point I was trying to make before: The catalogue, even if executed perfectly, would still select to...
Very neat overhead pass of the space station with docked shuttle from Southern Calif this evening. Here is a map of the ground track... http://is.gd/8cqd ...
In the Amateur Telescope Making series (book two), there is an article titled "The Richest-Field Telescope" and the author, S L Walkden (1914) performs the...
Thank you all for the thoughtful replies. What started this idea for me was the often heard question of "how big a telescope should I buy?" I was looking at...
Spaceweather.com today, Nov. 24, has given credibility to your sighting. Congrats! Grant Miller Warrensburg, Missouri ... from Southern Calif this evening....
The problem with using radial velocities is that in clusters (and nearly all galaxies are in clusters), there's a pretty large velocity dispersion as stuff...
Brian Skiff
bas@...
Nov 24, 2008 8:09 pm
21757
Someone asked me how far away the Great Rift was during a talk I was giving and I really had no idea what the answer was. I've been unable to find anything...
The reddening of stars along the Rift starts to kick in between 150 and 200 parsecs (sorry: call it 500 light-years). It probably doesn't have a sharp...
... I don't know. The usual methods of determining this sort of thing are fraught with uncertainty. Old techniques using star-counts, magnitudes, colors, and...
Brian Skiff
bas@...
Nov 27, 2008 6:28 pm
21762
While doing some other work, I happened across: http://simbad3.u-strasbg.fr/cgi-bin/cdsbib4?2003A%26A...405..585S ...where the distance and depth of the Aquila...
Brian Skiff
bas@...
Nov 27, 2008 10:08 pm
21763
Hi Brian, Thanks for the heads up. ... Why is this value "a more reasonable one than the old Weaver paper"? Is this solely because the value is based on...
Weaver wanted the rift obscuration to extend out something beyond a kiloparsec, whereas the clouds are probably a lot smaller, at least with the density that...
Brian Skiff
bas@...
Nov 27, 2008 10:37 pm
21765
Hi Brian, If that individual was Alastair Reynolds, he did write "Beyond the Aquila Rift" (2005 Sci-fi). But then again working for the ESA for twelve years,...
This may be of interest to southern-hemisphere observers doing early-morning viewing. This is copied from a post to 'vsnet' from Howard Bond. A somewhat more...
Brian Skiff
bas@...
Dec 1, 2008 1:31 am
21767
It may be worth mentioning that the Kitt Peak all-sky camera shows the evening conjunction in progress. Not the best view, but perhaps there'll be some...
Brian Skiff
bas@...
Dec 1, 2008 1:55 am
21768
Hi, Saw a very lovely view from my hometown a minute after sunset and a couple of minutes before unseasonal clouds sealed off the ceiling of the sky. My...
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