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Trouble Finding Nebulae

dso observing reflector beginner eyepieces
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#26 Titan63

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Posted 19 January 2020 - 09:53 PM

One good resource I use to check on what to expect when looking for Messiers are Uncle Rod's  short backyard messiers pages.

 

http://uncle-rods.bl...siers-from.html

http://uncle-rods.bl...siers-from.html

Thanks this is very helpful.



#27 Titan63

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Posted 19 January 2020 - 10:08 PM

When your outside with your scope, and see stars in the sky, Can you accurately aim the telescope at these? If yes, then it’s a matter of seeing, vs a matter of finding.

Are you using a good star chart? If your starting out, Pocket Sky Atlas is a good match for your scope.

Try scanning the area with a 50mm right-angle, correct image finder or binoculars. Is anything interesting visible? Those will be good targets to study with the telescope.
Start with the easy first.

 

Thanks for the tips! I'll check out the pocket sky atlas. 



#28 Titan63

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Posted 19 January 2020 - 10:24 PM

Oh, you should be able to see some great stuff with your scope, but yeah, your yard might be the limiting factor.  Another thing that helps me:  knowing exactly what to look for.  Checking out sketches of the targets can be great, or books like O'Mera's "The Messier Objects" etc.  And then, try on different nights.  Even night to night, with fluctuations in transparency, etc, will make a difference.  

 

  (Plus, if you see something from a dark site, it's easier to find from a less-than-ideal site.)  

 

A few of my favorites to try this time of year:

 

M42 and M43 of course

 

M78 can get washed out really easily, I find.

 

Hubble's Variable Nebula

 

The Eskimo Nebula (planetary nebulae are great)  

 

And then, with the aid of a UHC filter, Thor's Helmit near Sirius  (fairly obvious in a 10" from moderate light pollution.)  

 

Good luck!

Thanks! Will check out.


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#29 Starman1

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Posted 20 January 2020 - 06:40 PM

This is my first year with astronomy. I have an 203 x 1200 mm dobsonian telescope and I typically start with my 32 mm eyepiece (37.5 X) when searching for nebulae. 

 

However, due to light pollution in my area I don't seem to be able to find certain nebulae or may just barely see it, such as M78. I have tried my narrow band filter too but not helping. 

 

Is it due to light pollution or I need larger aperture? 

M78 is a reflection nebula with a relative broad spectrum of reflection.  Your narrowband filter won't help--it'll just darken the nebula the same as the sky.

Narrowband filters are most effective on Emission Nebulae, where the light is emitted in only a few discrete wavelengths.

 

However, even a larger aperture won't help much on nebulae.  They, like faint galaxies, are the very hardest objects to see from the Earth's surface,

which is why they are almost all of what the Hubble has imaged.

 

To improve the visibility of nebulae in general, try taking your scope to darker skies.  8" is plenty of aperture for many nebulae as long as the sky is dark.

If you move your scope to a site where the sky is 3 magnitudes darker (probably possible if observing in a city backyard), that's the equivalent of upping the size of your scope

to a 32", and the dark skies will yield better contrast in your 8" than a 32" at home.

 

For nearly all objects except nebulae, you'll have a better time seeing them at at least 100x--the sky will be darker in the field and the objects much larger.

Magnifications of 30-60x are much better in very dark skies, where the background is less bright and not washed out.

 

Of course, the usual caveats apply:

--don't look for faint objects with the Moon above the horizon

--make sure you are dark adapted (30-45 minutes outside away from lights) before looking for and at the faint objects

--make sure they are high in the sky--above a 30° altitude at least--to avoid extinction of the image from the thickness of the air


Edited by Starman1, 20 January 2020 - 06:40 PM.

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#30 jmillsbss

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Posted 21 January 2020 - 11:19 AM

Titan63  -  I just wanted to jump in here and share some experience, little as it may be...

 

I'm FAAAAARRRR from experienced.  I got a 10" Orion Dob in fall of 2018.  Yeah, it's a little more aperture, but the 8" is a very, very capable aperture and yes, you'll advance to see far more DSOs than you've found yet.  Given enough time, you too will find objects that, frankly, you're just skipping over now, not knowing what you're looking for, or where.  Now, PLEASE, do not think me a smart mouth looking to discourage a newbie.  I AM NOT!  If you follow my posts, you'll see I still ask "newbie" questions almost daily!   I want to encourage you in the strongest language...

 

Maybe you can't go to darker skies.  Maybe you're local seeing conditions are constraining you.  Perhaps you are skipping right over the DSOs a veteran would easily see.  Like my location, if the skies are clear and stars are sparkling, one might think, "Grab the scope.  It's gonna be AWESOME TONIGHT!"  Well, it's not.  I still struggle to comprehend seeing conditions.

 

I looked for the North American nebula and the Veil nebula for 4 months and couldn't find them.  I thought they were just really small and I must have been right on them but needed more power.  Or darker skies.  Or night vision.  Or somebody to come point my telescope for me!  What I finally learned:  Those are HUGE DSOs.  And they're best revealed, with my aperture and skies, when using a 2" 30mm eyepiece and an OIII filter.  First light with that setup and BAM!!!  There they were.  Right where they're supposed to be...

 

I also was able to view them with a 1.25" 32mm plossl and a 1.25" OIII filter, everything was just more constricted.  I like wider fields.

 

There are a few smaller nebulae available this time of year (winter), but the best time for nebula, for me anyway, is in the summer, when the Milky Way center is more present in the night sky, stretching North/South.  My dark sky map looks to be about the same as your's.  Get yourself a nice 2" wide field EP for low power.  Get a nice OIII and UHC filter as well.  Again, a long FL plossl and 1.25" filter would work too if that's what you've got.  The OIII is best for most nebula, but not all.

 

Soon the constellations will come into the night skies that will be full of galaxies.  The UHC is usually best for galaxies, not OIII, but the UHC filter will also darken the fields, including the light from distant galaxies.  It might be best if you used no filter at all.  You have to decide for yourself.   Gemini, Leo, Virgo are all rising late in the night now, but as the calendar advances, these fields will begin to present earlier and earlier in the night.  A good atlas or app on your phone would be very helpful, but time at the eyepiece is gonna be you're best bet.

 

One of the biggest issues I had when I first started was managing expectations.  The internet is full of Hubble pics and those are impressive to view, but we never see that through a telescope.  I think you have a perfectly capable scope.  You get 50 or 60 or 120 nights of viewing and we'll be talking about a whole different set of questions.  Just don't get discouraged!  The creation testifies about the Creator.  The cosmos are filled with the glorious and the subtle.  And every time you check off another target's location, don't forget about it.  The next time you see it, you'll see more detail.  And the next and the next and the next... Good luck!!!



#31 Starman1

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Posted 21 January 2020 - 04:51 PM

The UHC is usually best for galaxies, not OIII, but the UHC filter will also darken the fields, including the light from distant galaxies.

 

A UHC filter is intended for use on objects with their emission energy at 486.1nm (H-ß), and 495.9nm and 500.7nm (O-III lines), which are large emission nebulae.

Galaxies have a full spectrum and are only enhanced by darkening the sky, i.e. driving the scope to darker skies, or, sometimes, using higher magnification to enlarge the object while making the 

background sky a bit darker.  Nebula filters like a UHC don't help.

 

One thing I tell beginners is something we all find true: "You will never see less than you see when you first look through a telescope."

It's like playing a piano--no one plays a Rachmaninoff piano concerto the first time they sit at a piano,  yet, with a lot of practice and some time doing it,

it is possible. There is no activity we do in our daily lives that gets us used to looking at faint low contrast objects at the limit of our visions except looking through a telescope at that kind of object.

So, time in the field is what counts.  I've talked to many beginners who thought the Messier objects were small and faint at first, only to talk to them a couple years later and hear them talk about how large and bright they are.

 

But, the emphasis seems to be on galaxies and nebulae these days, and I blame the Hubble telescope for that.  When I started, the emphasis was on Moon, planets, double stars and star clusters.

An occasional nebula (M8, M42) or galaxy (M31, M33) was thrown in to the list of objects to observe.  I think beginners would do well to follow the old guidelines and wait to seek galaxies and nebulae until they have

some hours of observing experience.



#32 jmillsbss

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Posted 27 January 2020 - 01:14 PM

A UHC filter is intended for use on objects with their emission energy at 486.1nm (H-ß), and 495.9nm and 500.7nm (O-III lines), which are large emission nebulae.

Galaxies have a full spectrum and are only enhanced by darkening the sky, i.e. driving the scope to darker skies, or, sometimes, using higher magnification to enlarge the object while making the 

background sky a bit darker.  Nebula filters like a UHC don't help.

 

One thing I tell beginners is something we all find true: "You will never see less than you see when you first look through a telescope."

It's like playing a piano--no one plays a Rachmaninoff piano concerto the first time they sit at a piano,  yet, with a lot of practice and some time doing it,

it is possible. There is no activity we do in our daily lives that gets us used to looking at faint low contrast objects at the limit of our visions except looking through a telescope at that kind of object.

So, time in the field is what counts.  I've talked to many beginners who thought the Messier objects were small and faint at first, only to talk to them a couple years later and hear them talk about how large and bright they are.

 

But, the emphasis seems to be on galaxies and nebulae these days, and I blame the Hubble telescope for that.  When I started, the emphasis was on Moon, planets, double stars and star clusters.

An occasional nebula (M8, M42) or galaxy (M31, M33) was thrown in to the list of objects to observe.  I think beginners would do well to follow the old guidelines and wait to seek galaxies and nebulae until they have

some hours of observing experience.

Much better said than my attempt.  I was trying to compare/contrast the OIII and the UHC.  I probably shouldn't have tried!  I think a LPR might be helpful, more helpful than a UHC on galaxies?  In my very limited experience, on some galaxies, a UHC seemed to help.  I also find in most cases I do better with galaxies with no filter at all.  Once I find one, THEN I'll try a UHC.  Sometimes it seems to help, but not always.  Sometimes it is worse.

 

Like I've said, I'd probably do better to stay out of the deep end...



#33 JoshUrban

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Posted 28 January 2020 - 09:59 AM

Much better said than my attempt.  I was trying to compare/contrast the OIII and the UHC.  I probably shouldn't have tried!  I think a LPR might be helpful, more helpful than a UHC on galaxies?  In my very limited experience, on some galaxies, a UHC seemed to help.  I also find in most cases I do better with galaxies with no filter at all.  Once I find one, THEN I'll try a UHC.  Sometimes it seems to help, but not always.  Sometimes it is worse.

 

Like I've said, I'd probably do better to stay out of the deep end...

Nah, the deep end is great!  Plus, nobody expects deep enders to be normal or reasonable.  :)  

 

  In all seriousness, re: galaxy views, I've found that different eyepieces, and switching between them, a big help, and usually higher power than I think.  I usually use my lowest power to find them, but sometimes, if that fails, bumping up to a mid-power to search darkens the sky enough to make them jump out.  Those little ghosts sure are tricky sometimes!




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