With all this discussion about Polaris, I thought you might find a couple of photos I took back in 2002 that shows you that the earth's spin axis is close to, but not precisely at Alpha UMi. Take a look at http://www.pbase.com/tomcat/aurora. The right-hand picture (http://www.pbase.com/tomcat/image/5186538)shows how the stars move over about 4 hours. The star nearest the center of the arcs is Polaris; if it was precisely at the pole, then the arc would have been a point.
You may also find the animated GIF photos of a (relatively) rare low-latitude (Maryland) Aurora interesting.
73 & Happy New Year -- Tom
Thats awesome - so stars follow a circular track, and other objects from a line ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Tom Clark, K3IO Sent: Monday, 31 December 2007 4:02 PM To: AMSAT BB Subject: [SPAM] [amsat-bb] Re: Dont loose the north Importance: Low
With all this discussion about Polaris, I thought you might find a couple of photos I took back in 2002 that shows you that the earth's spin axis is close to, but not precisely at Alpha UMi. Take a look at http://www.pbase.com/tomcat/aurora. The right-hand picture (http://www.pbase.com/tomcat/image/5186538)shows how the stars move over about 4 hours. The star nearest the center of the arcs is Polaris; if it was precisely at the pole, then the arc would have been a point.
You may also find the animated GIF photos of a (relatively) rare low-latitude (Maryland) Aurora interesting.
73 & Happy New Year -- Tom _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Andrew,
Yes, the stars follow a circular path: they just sit there, and the earth rotates.
Looking at all the straight lines, most have a flash at a regular spacing. I expect those will all be aircraft. So, in the short time they take to cross the field of view, the earth does not rotate any meaningful amount. Interesting the ones with massive direction changes. I'd guess the location is not far from an airport. Not at all a good spot for Astronomy really :-)
Regards, Jim, ZL1TYF
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Andrew Rich Sent: Monday, 31 December 2007 8:00 p.m. To: Tom Clark, K3IO; AMSAT BB Subject: [amsat-bb] Re: [SPAM] Re: Dont loose the north
Thats awesome - so stars follow a circular track, and other objects from a line ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC [email protected] mailto:[email protected] http://www.tech-software.net
-----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Tom Clark, K3IO Sent: Monday, 31 December 2007 4:02 PM To: AMSAT BB Subject: [SPAM] [amsat-bb] Re: Dont loose the north Importance: Low
With all this discussion about Polaris, I thought you might find a couple of photos I took back in 2002 that shows you that the earth's spin axis is close to, but not precisely at Alpha UMi. Take a look at http://www.pbase.com/tomcat/aurora. The right-hand picture (http://www.pbase.com/tomcat/image/5186538)shows how the stars move over about 4 hours. The star nearest the center of the arcs is Polaris; if it was precisely at the pole, then the arc would have been a point.
You may also find the animated GIF photos of a (relatively) rare low-latitude (Maryland) Aurora interesting.
73 & Happy New Year -- Tom
-
Andrew Rich -
Jim Towler -
Tom Clark, K3IO