lost ra,dec dial settings

[dr. smith]

Hi, I need help understanding how my ra and dec dials on my telescope are to be set to find things by these settings.:confused:In the past I just look up and point the scope and hope to find things with little luck. I am sure the dial settings have been turned at one point or the other and have no idea how they are used.:)Could someone PLEASE help. Thanks, DR. Smith Lost in Space

[NickW]

I dont own one, but I did a quick search on google and came up with this:

http://www.astronomyboy.com/eq/

Let me know if that helps :)

[hhEb09'1]

Hi, I need help understanding how my ra and dec dials on my telescope are to be set to find things by these settings.:confused:In the past I just look up and point the scope and hope to find things with little luck. I am sure the dial settings have been turned at one point or the other and have no idea how they are used.:)Could someone PLEASE help. Thanks, DR. Smith Lost in SpaceWelcome to BAUT, dr. smith, we've been expecting you

NickW's link looks like it'll work (it starts with "How do I point the telescope at [some part of the sky]?")

The earth turns so that objects in the sky only move in RA, which means if your telescope axis is aligned with the earth axis, the telescope will swivel in RA as well. Your scope base has to be tilted the same number of degrees as 90 minus your latitude. A dec of 90 will then have your scope pointed right at Polaris, even in the daytime--so even if you changed the RA on your scope, it would still be pointing at Polaris. You're going to need some sort of sky map, to orient yourself, but once your scope set to Polaris, and you find some familiar object, set your RA circle to match the RA of the object and you're good to go. You could also figure it out from date/time and geographical position, only just a little more involved.

[dr. smith]

I dont own one, but I did a quick search on google and came up with this:

http://www.astronomyboy.com/eq/

Let me know if that helps :)
Hey thanks for the link. I guess my main objection or problem was just RA but I think I understand now how to properly set my RA dial. THANKS AGAIN!!!:)

[dr. smith]

Welcome to BAUT, dr. smith, we've been expecting you

NickW's link looks like it'll work (it starts with "How do I point the telescope at [some part of the sky]?")

The earth turns so that objects in the sky only move in RA, which means if your telescope axis is aligned with the earth axis, the telescope will swivel in RA as well. Your scope base has to be tilted the same number of degrees as 90 minus your latitude. A dec of 90 will then have your scope pointed right at Polaris, even in the daytime--so even if you changed the RA on your scope, it would still be pointing at Polaris. You're going to need some sort of sky map, to orient yourself, but once your scope set to Polaris, and you find some familiar object, set your RA circle to match the RA of the object and you're good to go. You could also figure it out from date/time and geographical position, only just a little more involved.

DEC isn't the problem, but if I lock say on the moon and I know what the RA is supposed to be at that time I just turn the RA dial to match? Hey, THANKS for your patients and support!!!!!

[RickJ]

Realize that unless the circles are at least 6" with vernier they will likely be of little use. Also unless the RA circle is driven you will have to constantly reset it for every object. If the scope is equatorial learn the right angle sweep method, it is far more accurate than most setting circles and far faster as well once you are on to it. I've been in this hobby after building my first scope in 1954 and still haven't found but one scope with circles, other than electronic ones, that were accurate enough to be of use. Right angle sweep is far more accurate and faster for me. When I did the Herschel 400 list in the early 80's I needed less than a minute to find an object on average including the time needed to find the object on the chart and then locate in the scope using my bit over a degree eyepiece. It even allowed me to discover a couple errors in the original listing. I was working from a provisional list, not the final version and the info described the wrong object! The person doing the list used setting circles while right angle sweep found the right one.

Basically you just find a star within a few degrees of the object you are looking for and note on a star chart how far, in degrees of arc, it is from the object you are looking for first in the declination direction then in RA. So if the object is 2.5 degrees north and 3 degrees east (you'll learn to eyeball this on a star chart very quickly) you just first center the star using an eyepiece with a known field of view. I use one that's just over 1 degree (time a star at the celestial equator is it drifts across the center of the field, it moves one degree in 4 minutes time). I then move the scope north watching the stars go by. One at the edge before you move that is now at the bottom means you moved one degree. Do this again and the third time stop when the star is in the center or whatever part of the distance is needed to indicate yet another half degree was traveled. Then do the same moving east. At first you may have to lock the axis you aren't using but soon you will get the hang of it. There are even databases on the net with the needed motions already calculated though it is quick and easy to learn reading any good atlas. I use a Telrad finder and my chart came with a Telrad overlay for the charts that allow me to do the RA sweep right through the Telrad, no scope needed. Though I can use the overlay to judge the distance on the chart if stars are too faint for just the Telrad. Google the term "Right angle sweep" with the quotes and you'll turn up lots of info. This one will give you the basics.
http://www.asgh.org/articles/ras.htm

Rick

[dr. smith]

Hey Rick, Thanks for the imfo. I'll figure out my lens and give it a try.