How to locate DSOs and cluster?

[legoalan]

Does anyone have any good advice or neat little tricks on how to locate DSOs (ie clusters and galaxies etc) using none electric equatorial mount and a standard finder? I would look to be able to see NGC2392 (the eskimo nebula), M1 (crab nebula) and M51 (whirlpool galaxy). If there are any other DSOs or object which are easy to locate please recommend them to me. I should add that my garden faces west, so my house blocks the east views and I canjust about see south and north.

Appreciate any advice as I am still a noobie observer

[rowan46]

do you have stellarium on your computer

Stellarium

Also which scope are you using? and how bad is your light pollution? these will have a bearing on what can be seen

[brantuk]

One way is to learn the constellations and the movement of the stars as Earth spins. There are seasons to astronomy so it takes a full year to get to know where all the popular stuff is. Then practise star hopping.

I use Stellarium (free download) to locate the rough position in the sky where I should be pointing and which constellation my object is in. It may help to make a list before each session initially. Four or five objects to find in a session soon builds up into a useful knowledge base. Star hop from known key stars in the constellations.

Or you can use a book at the scope on a picnic table. Turn Left at Orion will give you your first 100 objects. Illustrated Guide to Astronomical Wonders gives a whole lot more. Both have finding instructions, and illustrations of what to expect in the eyepiece.

Hope that helps

[Ewok]

I have to say that Turn Left At Orion was by far and away the most helpful purchase I ever made.

[glowjet]

I would support Brantuk`s recommendation to purchase a copy of Illustrated Guide to Astronomical wonders, goes much, much further than TL@O and is cheaper at around £16, this together with something like a Telrad finder will help you to star hop to your chosen target, but unless you have very dark skies and a fairly large aperture scope, objects like M1 for instance, are at the best difficult to see.

[rory]

stellarium, turn left at orion and astronomical wonders are all things i now own,and they help alot.

im a novice with a small (90mm) refractor and no finderscope to mention. so im currently searching with my lowest mag e/p (26mm)

even with this far from ideal set up,ive found a few clusters open and globular and the odd galaxy. i love the hunt.

like others tell you. they are faint, my scope shows little detail in my polluted area. so bear in mind you need to move slowly with the finder and dont expect big things to pop into your e/p when looking for dso's.

clear skies

[brantuk]

Hey Rory - keep an eye on the for sale section - finders come up regularly. A cheaper and very effective alternative is a Telrad - transforms your searching

[Dob]

It is very hard to find anything without a finder.

So, get one first.I never used Telrad but i can recommend you 9x50 finder.

[Kevdan]

Hi,

Im having the same problem as you, I have the stock 6x30 finder which is only slightly better thanusing your eyes, Im looking into a 9x50 raci and a telrad to supprt it.

Problem is when you look at stellariums ocular view it shows galaxies filling the eyepiece at around 70-80x mag so they shoud be easy to find but this is not the case.

Kev.

[Altair40]

I find my red dot finder useful to an extent if you can see the target by naked eye. I tried for M13 last night but no luck even though I could find it through bins.

I'm going to duck tape my monocular to the other side of the scope over a block of wood. Somewhere near the centre of pivot but I'll still need to re balance the scope. I'll look horrible but I want M13!

And some sort of finder...

[legoalan]

Thanks for the advice brant, I'll definitely try and purcahse those books.

rowan - I do have the stellarium as well as starwalk on my ipod touch to help me find them and my scope is an unbranded 150mm aperture 1400mm focal length newtonian reflector on an equitorial mount. The light pollution here isn't really that bad I dont think, it's the weather that's annoying.

So is it really worth it to get a telrad finder and swap out my stock 6X30 finder scope?

[Dob]

Hi,

Im having the same problem as you, I have the stock 6x30 finder which is only slightly better thanusing your eyes, Im looking into a 9x50 raci and a telrad to supprt it.

Problem is when you look at stellariums ocular view it shows galaxies filling the eyepiece at around 70-80x mag so they shoud be easy to find but this is not the case.

Kev.

Of course this is not the case.

Those are pictures taken through Hubble, and i blame Stellarium for that.(giving wrong impression to people)

You can take LP filter (UHC) which will improve view on nebulas but for galaxies onliest "filter" is dark sky.

[brantuk]

If you have no problems with the stock 6x30 finder then keep it by all means. I only suggested it cos Rory doesn't have one. But as an additional note - raci's are great for anyone who suffers with their back and the Orion 9x50 is a good bit of kit worth investing in - fits all S/W shoes

[swamp thing]

Hi

My advice is, get yourself a good star atlas, a finder with at least 50mm aperture and a Telrad.

With this set up you should be able to find pretty much anything in the sky.

Regards Steve

[twotter]

One approach I have tried is to adjust Stellarium, press <F4> and adjusted the light pollution number so the night sky looks more like what I can see from my garden - helps a lot.

I've replaced my 9x50 finder with a simple red dot finder, which makes targets easier to find. As I look through the RDF it's a simple job to place the red dot onto the background of stars, which looks like the screen image on Stellarium. Not saying I find every target first time, but as long as the seeing/light pollution etc... is fine, I seem to do okay.

Good luck

[rory]

Hey Rory - keep an eye on the for sale section - finders come up regularly. A cheaper and very effective alternative is a Telrad - transforms your searching

yeah, thanks for that. i shall have a browse. my birthday is coming up in a few weeks,and been hinting to my other half about the telrad.

[Foton Finder]

Short answer: YES.

a 6 x 30 finder is not much help at all. A hollow peep sight might be a superior instrument! I find that a Telrad or a Rigel Quick Finder can help you find a low-power field of view pretty well with some practice. A finder of 50 mm + can then help you refine the aiming further, and allows you to see asterisms that you won't see naked eye.

Most finders are straight-through affairs, so remember that the image will probably be reversed from the naked eye (and chart) view. Right angle finders annoy me, so the "advantage" of an erect image escapes me. A terrestrial 'scope, with an image that's corrected in altitude as well as azimuth would be helpful, but they usually have a "crook" in them due to the prism assembly, so you can't easily sight down the side of them.

Then, as far as actually finding things, you can learn to "star hop", or, with an EQ mount and knowledge of the field of view (of the finder, the main scope, or the Telrad), you can step off a known object in RA or DEC by a number of degrees (from a good map), and with practice, find hundreds of objects.

I'd also recommend Terrance Dickinson's Nightwatch as a good beginning reference book.

Clear skies,

[legoalan]

Thanks for the advice Foton Finder =). Can you explain about the star hopping part about using "RA or DEC by a number of degrees"? I don't really understand that part =P

[Foton Finder]

OK... This is a technique for finding objects with an equatorial mount, without using setting circles, in the classic sense. It doesn't need to be a permanently mounted telescope, but portable instruments should be at least roughly polar aligned first. If you need help with that part, search under "polar alignment".

The general idea is to find an object you want to view on a star chart, and see how that object relates to other bright, or easy-to-find objects. For example, M-65 and M-66 are just a few degrees away from a naked-eye star in the "triangle" section of Leo, which is high in the sky when darkness falls this time of year.

Start with Theta Leonis, also called "Chertan", which is the star at the right angle of the triangle asterism to the east of the sickle of Leo. Its also the dimmest of the three, and as seen from an observer looking south, the "lower right" star of the triangle. If you center that star in your finder scope (or Telrad or similar device), you can lock the right ascension axis, and sweep 2 degrees south in declination, then lock the Declination axis and loosen the RA, and sweep about 1 degree to the east, and bingo! you're looking at M-65!

SO, you ask... how do you measure 2 degrees ? Well, if you have setting circles, you can use them. If not, and you have a Telrad or Rigel Quick-Finder or similar zero-power finder, they have a scale built-in, and learning how to match the circles on the Telrad to a star map is a very good idea. Otherwise, you can figure out the FOV of an optical finder by comparing it to a star chart. find any two objects that will just fit in the field of view, and with the star chart, measure the distance between them. If the field is 5 degrees, for example, you can use that as a rough "yard stick" for measuring offsets, in degrees.

You can --and should -- also measure the FOV of your lowest power eyepiece by timing how long it takes a star near the equator and your local meridian (that is, when facing south) to cross the field of view of a stationary telescope. The Earth rotates 1 degree every 4 minutes, so if it takes 6 minutes for a star to drift all the way across the view (just a made-up example), that would be 6 minutes divided by 4 minutes per degree, or 1.5 degrees FOV. You can then use that to step your way across the sky.

Returning to Leo, start with Theta, then move about 0.25 degrees east (front of scope moving to the left, when facing south), then south (down) by 2 degrees, and you can see a star just bright enough to see with the naked eye. It appears in the finder or binoculars to be the top of a little "L" shaped group of dim stars. M-65 and M-66 are just 0.75 degrees to the east of this star group.

With some practice, both star-hopping and RA/DEC Sweeps can be used to find most anything, without all that fussy go-to stuff. The major difference is that an EQ mount, when polar aligned, maintains its orientation to the earth and sky wherever it is pointed, while an alt-az mount like a DOB only lines up when looking due south or due north.

Make sense? Clear skies,

[legoalan]

Thanks foton finder, I think I know what to do now. I just saw M35 and M53 last night and it was pretty awesome =D. Thanks for all the advice everyone =]

[banner001]

The light pollution here isn't really that bad I dont think, it's the weather that's annoying.

So is it really worth it to get a telrad finder and swap out my stock 6X30 finder scope?

IMO a finderscope is better than a telrad, but if you can afford it you should really use both, maybe you should look at getting a slightly higher mag finder, like a 9x50. that way you put the telrad into the part of the sky you want to look at, the largest circle in the telrad corresponds to the view in the finderscope, you then slew until the finderscope is correctly aligned and then look through the EP...it should be in the middle of the view

as for light pollution, are you in kenilworth thats near coventry? your light pollution is ok, but birmingham, leamingtoh spar and coventry are big places and are both fairly close, you will get better skies to the west of Southam, or to the south of Wellesbourne.

[legoalan]

Hi banner, to answer you question yes I live in the town kenilworth thats near coventry and leamington. I think the light pollution isn't too bad. The main problem is the weather =[ Thanks for the advice about the finder scope. I'm wondering about what the difference is between a telrad and a normal red dot sight or are they basically the same?