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Issues finding objects

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#1 SMA+28.13

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Posted 21 January 2021 - 11:51 AM

I have recently bought my first telescope and I am having issues with finding objects using the Equatorial mount. I have polar aligned the telescope and aligned the RA Dail when looking at the moon, but I am still unable to find an object by setting my telescope's mount to it's RA and Declination.
Telescope: Celestron Powerseeker 127EQ
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#2 eyeoftexas

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Posted 21 January 2021 - 12:17 PM

I assume you have aligned your finder scope with your main scope.  Your field of view might be fairly narrow looking through the main scope trying to find small objects.  What objects have you tired?  You might be trying for sights that are too small/dim for your skies (light pollution).



#3 sg6

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Posted 21 January 2021 - 12:20 PM

Which Eq mount is it?

Found the Celestron site and the one there looks basic, very basic.

 

First you polar align the mount not the telescope. You can polar align a mount without a scope on it. So you are mixing things up a little at least.

 

The apparent standard Eq mount with the 127 has no provision for a polar scope so cannot in itself be polar aligned.

 

In a way you are hopefully doing the best you can. Which I hope is to have the scope and what is a best guess at the RA axis parallel to each other. Then you adjust the mount but NOT the scope bit to get polaris at least central.

 

That is I guess the best you can do but you do not move the scope via the slow motion twiddly bits, you only adjust the mount. Sorry not easy to explain.

 

Next I suspect you cannot use the moon as the start RA point. The RA of the moon alters daily and by quite a bit. So I suspect that does nothing to help.

 

As Polaris more or less remains stationary use that for RA.

 

Then you can rotate the Dec and RA to the desired values of the next target.

 

My guess is that the Polar Alignment is a little incorrect, the use of the "telescope" is likely that area and the bits you move to get Polaris in view. I half suspect you are moving the scope more then the mount.

 

Next is not to use the Moon. It is big, bright, easy to find but unless you are using the correct daily and likely hourly value you will not have the correct initial RA value.

 

Will warn you Eq mounts are a real pain.

At outreach I was once asked "How would you find something over there?"

I sort of blindly hoped that getting the right RA  and Dec values would have the scope aiming "over there" - I had found the RA+Dec of a star in that area. Magically it worked. They were impressed, so was I.



#4 Astrojensen

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Posted 21 January 2021 - 12:30 PM

 

The apparent standard Eq mount with the 127 has no provision for a polar scope so cannot in itself be polar aligned.

Here I'm afraid YOU are mixing things up a little. wink.gif  Of course you can polar align an equatorial mount without a polar alignment scope. It's just a bit more involved. 

 

 

I suspect you cannot use the moon as the start RA point. The RA of the moon alters daily and by quite a bit. So I suspect that does nothing to help.

The Moon changes its RA continuously. You CAN use it to set the RA circle, but you'll have to be quick about it. It's better to use a star. 

 

 

Will warn you Eq mounts are a real pain.

I disagree. When you learn how to use them, they have several advantages. But like with so many other things, it must be a good, quality product, before all the advantages become obvious.

 

I would advice the OP to forget using the setting circles on the very basic mount. They are almost worse than useless, because they are far too small to be read with the required accuracy. That is the unfortunate truth.

 

 

Clear skies!

Thomas, Denmark


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#5 bobzeq25

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Posted 21 January 2021 - 12:31 PM

This can help.

 

https://www.amazon.c...e/dp/1108457568


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#6 michael8554

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Posted 21 January 2021 - 12:57 PM

The RA and Dec dials on your mount are too small in diameter to give readings accurate enough to hit a target spot-on.

 

Your best bet is to centre a bright star near your target that you recognise such as Vega, Capella, Arcturus, Betelgeuse, Aldeberan etc.

 

Set the dials to the star's RA and Dec, then quickly move the mount to the target's RA and Dec.


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#7 Hesiod

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Posted 21 January 2021 - 12:59 PM

Indeed, the best thing you could do is to use the finderscope (that little spyglass sitting atop the "telescope") and forget about the setting circles.

 

Set up your telescope as usual, and try to get a decent polar alignment; then find a bright star which has roughly the same DEC (or RA: it is the same, choose the one you feel more convenient to move), place it in the middle of the finderscope's field of view, then slew the DEC axis until see the target.

Mind that some objects are quite "tricky" so, instead of going straight for them may follow a "path" of stars (this is called "star hopping" as jump from one star to another. It is very popular with alt/az mounts but works even with equatorial ones); or can try to "pinpoint" the location by exploiting the fact that your finderscope has a definite field of view (a common value for 6x30 is around 8°).

Once in the offing of your target you should look carefully in then finderscope (and then in the eyepiece, better if at low power) to recognize star patterns around the target: again, most deep sky objects are quite elusive, either because are too small (most galaxies and planetary nebulae are such: a common error is to use too low magnification) or too large (that is the case of the elusive M33, one of the very few large galaxies, or of the North America Nebula), or too faint to be seen easily.

To make practice I suggest to start from very bright and easy recognizable objects (e.g. Mizar/Alkor, Betelgeuse, M42, the Pleiades, or anything else you can see by your naked eye) and once have become familiar with the technique may attempt more elusive pursuits


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#8 Voyageur

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Posted 21 January 2021 - 01:03 PM

What objects in particular have you tried to locate? Some objects are very dim and hard to see, especially if there is any light pollution (usually the case) or if there is a bright Moon. Also, the setting circles on that mount are not very accurate. The scale is pretty crude, and it is not possible to accurately dial in RA and DEC so that you will be certain to be centered on a very small, distant object.

 

In other words, you might be pointed right at an object, but be unable to see it, or you may be close, but the object is outside the field of view and you don’t know exactly which way to move the scope to get it into view. Inexpensive EQ mounts can be very frustrating. My first scope was a Newtonian reflector on a cheap manual EQ mount, and I upgraded as soon as possible from it. With some patience, you can learn to locate objects with it, but it will help to try for objects that you have a reasonable chance of finding. The book recommended above, Turn Left at Orion, is a good place to start.


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#9 astronomus1930

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Posted 21 January 2021 - 01:19 PM

Just a little addition to michael8554's advice is to be sure to use your lowest power eyepiece to acquire a target. A scope's FOV is small. Acquiring targets is an art- just stay with it!

 

Good hunting!



#10 oldtimer

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Posted 29 January 2021 - 11:08 AM

Last bad new, google 'Telescope Bllacklist' 



#11 spereira

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Posted 29 January 2021 - 12:58 PM

Last bad new, google 'Telescope Bllacklist' 

???

 

smp



#12 Dave Mitsky

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Posted 29 January 2021 - 01:47 PM

The technique that michael8554 mentioned is known as offsetting.  It's described in the section on setting circles at https://www.skyatnig...etting-circles/ and https://skyandtelesc...your-telescope/



#13 kathyastro

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Posted 29 January 2021 - 02:18 PM

The setting circles on the typical consumer-grade EQ mount are not accurate enough to find a target.  However, if you use them correctly, they will get you close enough that your target is in the field of view of the finder scope.  And, if the finder scope is properly aligned, centering the object in the finder will place it in the field of view of a low-powered eyepiece in the main scope.

 

So, using the circles properly...  Yes, the Moon will kind-of work, but it is a poor choice because it is so big and because it moves so fast.  You are better off to pick a bright star.  Centre it in the eyepiece.  Then look up its RA and dec, and set the circles accordingly.  Then, for a few minutes, you can use the circles to get your target into the finder.  Note that you will have to recalibrate the RA circle every time you move to a new target, because the setting circle will not track the sky as it moves.

 

Aligning the finder...  You can do this in the daytime if you have a view of a distant enough target.  A mountaintop, or a radio mast on a hill, or a distant building are suitable alignment targets.  The farther away, the better.  Point the scope at the target and get it centred in the eyepiece.  Now, shift to the finder and identify the same target.  Without moving the main scope, adjust the finder so that the same target is centred on the cross-hairs.


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#14 hcf

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Posted 29 January 2021 - 02:49 PM

+1 for learning to "starhop". Learn Stellarium (free on pc/mac) or Sky Safari (paid but worth it on phone/tablet) and buy the book Turn Left at Orion (used ones on ebay are fine)

 

 

If you are into raspberry pi/linux software etc, you can build yourself a gizmo which will show you on Sky Safari, where the scope points in the sky at any time, with a small delay.

 

You can then use it as a pushto. Works with any mount, EQ or Alt/Az.

 

https://www.cloudyni...sual-astronomy/


Edited by hcf, 29 January 2021 - 02:50 PM.


#15 Sheol

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Posted 29 January 2021 - 07:14 PM

                              There are reasons EQ mounts have waned in popularity. And for newbies, they are not easy to set up. I would only go back to GEQ mount if it came with very good GOTO and excellent tracking..

 

                                 Clear Skies,

                                       Matt.


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#16 therealdmt

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Posted 30 January 2021 - 01:34 AM

First, know that those setting circles are really small and so are only going to be useful for getting you into the general area, not right on a target. Once you’re in the general area, you can hopefully find the target somewhere in the finderscope’s field of view, and then from there you can center it in the finderscope and (assuming you aligned the finderscope with the telescope on a distant target during the day), you should be able to see your target object in the telescope, especially if you’re using the low magnification (20mm) eyepiece.

 

Start with the brightest stars first, just for the practice. Can you get the scope onto Sirius, the brightest star? After that, try Aldebaran in Taurus. If this isn’t working, study up on polar aligning your mount (read, YouTube, ask about it here on Cloudy Nights, etc.). Other bright stars to practice on that you can see even in a light polluted sky this time of year include Betelgeuse, Rigel, Capella and Procyon. These stars aren’t particularly exciting to look at in and of themselves, but it’s just to practice getting yourself, the mount, finderscope, telescope and eyepiece all working together to view a specific piece of the sky and to then transition from there to a different particular piece of the sky. After a dedicated practice session or three, you’ll be in much better shape!

 

Once that stuff becomes pretty easy, try tackling Pleiades and then the Orion Nebula, both of which you can see naked eye and easily see in your finderscope. Then move on to bright open clusters (these will be harder to see in the finderscope, but achievable after you have just a little experience).

 

Hint: if you’re trying to start off with M1 or with a galaxy, globular cluster or faint nebula, those are challenging targets that you’re not quite ready for yet. Also, be patient. After this practice, once the planets come back around in a few months, you’ll have them as prominent, rewarding targets that will by then be easy for you to find and track!


Edited by therealdmt, 30 January 2021 - 03:30 AM.

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#17 michael8554

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Posted 30 January 2021 - 06:27 AM

                              There are reasons EQ mounts have waned in popularity. And for newbies, they are not easy to set up. I would only go back to GEQ mount if it came with very good GOTO and excellent tracking..

 

                                 Clear Skies,

                                       Matt.

What would you suggest as an alternative to a EQ/GEQ mount ?



#18 Hesiod

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Posted 30 January 2021 - 08:08 AM

                              There are reasons EQ mounts have waned in popularity. And for newbies, they are not easy to set up. I would only go back to GEQ mount if it came with very good GOTO and excellent tracking..

 

                                 Clear Skies,

                                       Matt.

Reasons which has little to do with how the mounts work, and much with how crap some of  the smallest eq mounts are. A bad mount is a bad mount, regardless of the design, and in truth there are also hideous alt/az ones.

Also the ever-growing size of entry level telescopes makes less and less convenient resorting to conventional mounts so, with some deplorable exceptions, those telescopes are offered as Dobs.

 

Setting up a German eq mount for a stargazing session is not really much different from setting up an alt/az: I have two "sort" of manual GEMs with clock drive I use as my grab and go telescope and can deploy them even for 15' sessions.

Grab the mount, go out, lay it down facing the pole and are set; sometimes, if am for a prolonged session, may even use the polarscope for an accurate alignment but that takes very little (10"?20"? Peek in the polrascope, turn a couple of knobs and go).

If want a fully manual telescope and opt for a  refractor or Cassegrain in my opinion the good old German Eq mount is very hard to beat because intertwines the benefits of manual mounts with the option to have motorized tracking, which is a very nice treat.

 

As for finding objects, GEMs and EQ mounts in general may work exactly as alt/az mounts (nothing prevent from using them to star-hop), and of course retain the ability to be aimed through knowledge of equatorial coordinates (which are more practical than alt/az ones, which really need ephemerides or a planetarium software)


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#19 seasparky89

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Posted 30 January 2021 - 10:00 AM

Mounts, such as the Atlas and Sirius have reasonably sized setting circles.  In fact, I have one of the original Atlas mounts that did not have go-to.  So, I learned to use the well-sized circles for more than two years with great success before upgrading to go-to.  The setting circles, plus tracking, really make the GEM stand out IMHO.



#20 hcf

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Posted 30 January 2021 - 12:55 PM

Low end alt az mounts often do not have slow motion knobs but low end GEMs always do. If you have the right scope (short and light) on them, they work fine.

 

And if you can add some tech to your low end GEM, you can get an amazing user experience of a grab and go with very accurate GoTo:

 

https://www.cloudyni...-project-ps-g2/

 

No star alignment needed, approx polar alignment works fine, no need for Lat/Long/Time settings. Very accurate GoTos everytime, controlled from Sky Safari Pro/Plus, and you can move the scope by hand by loosening the clutches without affecting GoTo.

 

You do have to align a small camera to the scope, but like a RDF, it holds alignment if you dont remove it from the mount.

 

The same concepts could be used on Alt/Az mounts, but those are often not designed to be motorized, so it is much harder.


Edited by hcf, 30 January 2021 - 12:57 PM.

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#21 teashea

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Posted 30 January 2021 - 06:19 PM

Watch a few youtube videos on polar alignment.  It is tricky and you must be precise.  



#22 teashea

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Posted 30 January 2021 - 06:33 PM

This is a most excellent suggestion.  It is quite famous and rightly so.  

 

I might also suggest that if you have a pair of binoculars available, you should use them instead of a telescope to begin becoming familiar with the whole process.  



#23 CarolinaBanker

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Posted 31 January 2021 - 10:42 AM

I have recently bought my first telescope and I am having issues with finding objects using the Equatorial mount. I have polar aligned the telescope and aligned the RA Dail when looking at the moon, but I am still unable to find an object by setting my telescope's mount to it's RA and Declination.
Telescope: Celestron Powerseeker 127EQ

Look into Turn Left at Orion. It’s a great approach to star hopping.


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#24 vtornado

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Posted 31 January 2021 - 07:50 PM

I have a cg4 mount which is one upgrade over yours.  

 

The setting circles kind of work.  however they are small.

The best way to use them is to minimize the hop.  Find a bright star near your target and set the RA and dec on that.

Then make the short hop.   I cannot move my scope 4 hours in RA and expect  it to be close to the target.

More like one hour to two hours is the maximum hop.  Some dec circles are not movable, so once you have

something in your main scope note the deviation in the declination reading and use that for your new target,

noting the variance between actual and the dial reading.

 

Note also your mount head has to be level.  Typical suburban lawns and driveways are not level the grade is away

from the house, and driveways generally slope down to aid in water runoff.  If this is the case the latitude scale

is off.

 

Another thing is that my CG4 had the latitude scale roughly 5 degrees off of actual.  I put a digital angle guage

on my RA axis to figure this out.  I popped off the plastic cap that had the latitude reading and repositioned it

and glued it down.  If you don't have an angle guage you can point the RA axis to zero or 90  and determine

if it is truly level or vertical.  Then a torpedo level can be used, or you can hang a makeshift plumbline

from it, to assess accuracy.


Edited by vtornado, 31 January 2021 - 07:51 PM.



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