Archive for the ‘Thoughts & Ramblings’ Category
Help Wanted: Spatial Analysis of 2010 Perseids
I received this email with a request to help spread the word. Sounds interesting!
This will be one of the better years for Perseids; the moon, which often interferes with the Perseids, will not be a problem this year. So I’m putting together something that’s never been done before: a spatial analysis of the Perseid meteor stream. We’ve had plenty of temporal analyses, but nobody has ever been able to get data over a wide area — because observations have always been localized to single observers. But what if we had hundreds or thousands of people all over North America and Europe observing Perseids and somebody collected and collated all their observations? This is crowd-sourcing applied to meteor astronomy. I’ve been working for some time on putting together just such a scheme. I’ve got a cute little Java applet that you can use on your laptop to record the times of fall of meteors you see, the spherical trig for analyzing the geometry (oh my aching head!) and a statistical scheme that I *think* will reveal the spatial patterns we’re most likely to see — IF such patterns exist. I’ve also got some web pages describing the whole shebang.
Chris Crawford
Crepuscular rays uncommon?
Crepuscular rays occur when objects such as mountain peaks or clouds partially shadow the sun’s rays. The name crepuscular means “relating to twilight” and these rays are observed at sunrise and sunset. Crepuscular rays appear to diverge outward from the setting sun, and are visible only when the atmosphere contains enough haze or dust particles so that sunlight in unshadowed areas can be scattered toward the observer.
The light rays are actually parallel, but appear to converge to the sun due to “perspective”, the same visual effect that makes parallel railroad tracks appear to converge in the distance. Crepuscular rays are often red or yellow in appearance because blue light from the sun is selectively scattered out of the beam by air molecules.
I live about 15 miles WSW of Tampa and crepuscular rays are a common occurrence. I suspect that what is causing them here are the buildings in downtown Tampa to the east in conjunction with the “flatness” of Florida. I’ve been observing them for years about 1/2 hour before sunrise and have never really considered them uncommon phenomena. It will be interesting over the next few days to see if they appear in the same configuration. If so then they are not caused by clouds… and CERTAINLY not by mountains.
Apologies to fellow bloggers
Over the years of neglect endured by my blog’s software engine (if it ain’t broke right?) somehow my blogroll and all my links stopped appearing on my site. Apparently my software was so out of date that the original db calls we no longer supported!
Anyhoo, I’ve rectified this and verified/updated all my links. I hope nobody thought I had just deleted them from my blogroll… no one even told me.
New Scope
I had not intended to purchase a new telescope as I’m barely finding the time to use the one I have. My wife had gone out shopping with a friend who works at a well known retailer. This friend was enjoying a 50% discount on EVERYTHING in the store today by virtue of it being “Black Friday” and the fact that she was also an employee. I should mention that this particular retailer is NOT known for it’s electronics/optics… in fact I expect it’s rather shunned in this regard, but I digress.
I was sitting at home with the kids when I received a call from my wife, whose keen eye had spotted a lonely Meade box up on a shelf. She’d asked the clerk if this was included in the 50% off and was told yes. She was calling to see what scope I had and/or if I was interested in a Meade ETX 125EC. The box was labeled $720.99 but she would get it for $310 plus tax…
?!?!?!?!?! … HECK YES I WAS INTERESTED!
But the story does not end here my droogies, for when your humble narrator — yours truly — opened the box at home he found not an electronic controller (EC), but a #497 Autostar. Further, upon examination of the optical tube assembly (OTA) he discovered a UHTC label… Ultra High Transmission Coatings. This particular scope with the Autostar and UHTC sells for $1094.
Nearly all of my ETX 90AT accessories will work with the new scope. I will need to purchase a new solar filter and motorized focuser at some point, but doing without isn’t going to stop the show. The only downside to all this is that I think I just got my Christmas present.
Needless to say I can’t wait to get it outside!
