Tracking stars and DSOs

[goranmagdic]

One of my concerns when buying a dob was how fast planets would move across the field of view. I've managed to view Jupiter at 120x and follow it well enough to allow friends to view. Due to weather conditions, I've not been able to view much else.

How different is the speed of star clusters and DSOs? Are they easier/harder to track?

[oldpink]

shouldn't be any harder to track than a planet

[Tinker1947]

There's very little difference in speed (nothing you will notice) , the high the magnification the fast they appear to move across your FOV, My choice would be a Dob with GoTo so having found the DSO either manually or with the GoTo the Dob will track it while i'm off having a cuppa tea or what ever....

[acey]

The rate at which an object moves across the sky depends on its declination - the Pole Star virtually stands still, while other targets appear to go faster as you move towards the celestial equator. The rate at which they cross the view of an eyepiece depends on the eyepiece FOV and magnification. The amount of motion you can put up with depends on the sort of detail you're looking for, and personal taste. But for what it's worth, I use a 12" hand-pushed dob for viewing DSOs at magnifications up to x375, with my highest-power EP being a wide-angle type (82 degree apparent field) so as to keep the target in view for longer. Works fine for me, and for thousands of dob users all over the world.

William Herschel used an undriven alt-az mounted telescope and went to powers of over x1000. He had geared slow motion controls to make tracking easier - they would be a very good idea on commercial dobs. But manufacturers know that customers are more easily lured by fancy electronics rather than simple mechanical solutions. Maybe some day I'll get round to fitting slow motion controls to my dob. For the time being I don't really need them.

Or you could always put the dob on an equatorial platform (aka poncet platform).

[rwilkey]

The speed at which DSO and clusters move always appears a lot slower because a planet appears as a small pea and therefore appears to move quicker, but it is only the earth turning.  Jupiter excels around about 150x to 180x, but something like Saturn can take more magnification.  Once you find it you won't loose it as the adrenelin kicks in and you want to see more.  It's one of those things that you get used to when viewing.  Wider field eyepieces always help of course.

[goranmagdic]

Following Jupiter at 120x with the stock 10mm EP wasn't too difficult, and I've ordered a BST 8mm for 150x. Just need some clear nights to practice now!

[AndyWB]

I find that DSOs are easier to track as I'm usually using much less magnification than on planets, and therefore the field of view is much greater. The only thing as difficult (or more, to be honest) is splitting doubles at high magnification.