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#1
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The UTC thread
It should be quite clear to anyone in astronomy by now that UT or UTC or GMT
is Universal Time. Those who don't have any concept of this designation should really consider just what level of amateur they really are. Astronomical observing is completely dependent on timing. It is just easier if people report observations of any kind in UTC. People should know what their local offset is whether it is Daylight or standard, PDT, MST, MDT,EDT,Europe, China or Antartica!! For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. |
#2
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For those of us who do orbital mechanics for a living, UT, UTC and GMT is
just the beginning... But you don't need to know any of those things to discover a comet, make a new observation on a variable star, discover a new supernova, etc. Let's not degrade other people because making time conversions makes you irritable... -- Clear Skies, Chuck "MikeThomas" wrote in message news:6bqTc.20328$fz2.3652@edtnps89... It should be quite clear to anyone in astronomy by now that UT or UTC or GMT is Universal Time. Those who don't have any concept of this designation should really consider just what level of amateur they really are. Astronomical observing is completely dependent on timing. It is just easier if people report observations of any kind in UTC. People should know what their local offset is whether it is Daylight or standard, PDT, MST, MDT,EDT,Europe, China or Antartica!! For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. |
#3
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"Sam Wormley" wrote in message ... MikeThomas wrote: It should be quite clear to anyone in astronomy by now that UT or UTC or GMT is Universal Time. Except there are subtle differences between those three that astronomers should definitely know. See: http://www.edu-observatory.org/gps/time.html http://scienceworld.wolfram.com/astr...ersalTime.html Innovation: GPS and Leap Seconds, Time to Change?, GPS World, Nov 1999 Look, I am not referring to astronauts and space exploration. You are splitting hairs. Why don't you offer up some useful information? |
#4
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MikeThomas wrote:
It should be quite clear to anyone in astronomy by now that UT or UTC or GMT is Universal Time. Those who don't have any concept of this designation should really consider just what level of amateur they really are. Astronomical ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^ observing is completely dependent on timing. It is just easier if people report observations of any kind in UTC. People should know what their local offset is whether it is Daylight or standard, PDT, MST, MDT,EDT,Europe, China or Antartica!! For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. Please tell us, Mike, what level of amateur are YOU? Regards, Etok __________________________________________________ _____________________________ Posted Via Uncensored-News.Com - Accounts Starting At $6.95 - http://www.uncensored-news.com The Worlds Uncensored News Source |
#5
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While reading in the bathroom on Sat, 14 Aug 2004 15:26:58 GMT, I saw
that "MikeThomas" had written: For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. ???????????? To do a polar alignment, I line up on the pole star. Time has nothing to do with it, although knowing how to put my 'scope in its "home" position is critical. For a planisphere, with the amount of light pollution around here, I can be as much as an hour off without screwing up my ability to find something in the sky. For using Autostar on my goto (ETX-125), accuracy to within a couple of minutes is adequate. You do have to know your time zone, and whether you're in daylight or standard time, but even the exact long-lat isn't necessary. I do have the knowledge and capability to be more precise than that but, as someone else said, we're not astronauts, and astronomy isn't rocket science. The night sky doesn't move that fast and a wide-enough FOV will give you plenty of margin. -------------- Beady's Corollary to Occam's Razor: "The likeliest explanation of any phenomenon is almost always the most boring one imaginable." -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#6
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On Sat, 14 Aug 2004 14:08:01 -0400, John Beaderstadt wrote:
I do have the knowledge and capability to be more precise than that but, as someone else said, we're not astronauts, and astronomy isn't rocket science. The night sky doesn't move that fast and a wide-enough FOV will give you plenty of margin. My telescope pointing accuracy is around 30 arcsec. That corresponds to 2 seconds of time error. Since I don't sync my scope, but rely on an accurate time and pointing model, I depend on very accurate time measurement. Of course, if you are working visually, and syncing you scope to calibrate the RA, than you don't need much accuracy at all. For occultation timing, a second is a large error. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
#7
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John Beaderstadt wrote:
While reading in the bathroom on Sat, 14 Aug 2004 15:26:58 GMT, I saw that "MikeThomas" had written: For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. ???????????? To do a polar alignment, I line up on the pole star. Time has nothing to do with it, Personally, I try to line up on the North Celestial Pole (since I live in the northern hemisphere). While time affects the position of Polaris, it does not affect the position of the North Celestial Pole (ignoring precession). If you use Polaris as a polar alignment aid, you need to know the time of day, unless your error tolerance is big enough. although knowing how to put my 'scope in its "home" position is critical. That is not critical at all in my case, as I use drift alignment using a german equatorial mount. Clear skies Carsten A. Arnholm http://arnholm.org/ N59.776 E10.457 |
#8
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MikeThomas:
is completely dependent on timing. It is just easier if people report observations of any kind in UTC. People should know what their local offset is whether it is Daylight or standard, PDT, MST, MDT, EDT, Europe, China or Antartica!! So in what time zone(s) are the north and south poles located? Both points are on every meridian and on no meridian. For one thing, to do a polar alignment, you have to know your local time meridian offset and whether you are east or west of it. I drift-align my Questar without reference to any time at all. After the alignment I need to know the R.A. of a star -- any visible star -- in order to move my R.A. setting circle to the correct position as a reference for finding other objects of known R.A. But I still don't need to know what time it is in Tuguegarao* or Shibam-Kawkaban**, or, indeed, where on earth I am. Davoud * generally poor for deep sky, good for solar system ** great skies, but a dangerous place -- usenet *at* davidillig dawt com |
#9
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MikeThomas wrote: People should know what their local offset is whether it is Daylight or standard, PDT, MST, MDT,EDT,Europe, China or Antartica!! Hmmm .. wonder what the offset is at the South Pole? g |
#10
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While reading in the bathroom on Sat, 14 Aug 2004 21:18:47 +0200, I
saw that "Carsten A. Arnholm" had written: If you use Polaris as a polar alignment aid, you need to know the time of day, unless your error tolerance is big enough. Which is the big advantage of a goto scope. For polar alignment, I just need to be in the ballpark; then I do the "Easy" two-star alignment and I'm set for the evening. -------------- Beady's Corollary to Occam's Razor: "The likeliest explanation of any phenomenon is almost always the most boring one imaginable." -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
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