Jump to content

sgl_imaging_challenge_2021_annual.thumb.jpg.3fc34f695a81b16210333189a3162ac7.jpg

Recommended Posts

Hi all, i recently purchased my first telescope, I have a 10" Dob, I'm in a bortle 5 area, I want to see Dso's ,I have lined up my finder to my scope, i can easily find m42, however after 10+ hours of viewing, the orion nebula is still the only nebula i can find! I have a 2" ep which I use for finding, I also have a light pollution filter attached, I use stellarium for locating nebulas. Any idea what I could be doing wrong? I have been trying to view the jellyfish nebula as it's easy to find but I only see stars? Any help will be much appreciated. Thanks. 

Link to post
Share on other sites

Hi, I'm guessing that the Jellyfish Nebula is incredibly faint and more of a target for photographers- I couldn't find a magnitude for it. In the same area is M35, which should be easy to see. I recommend starting on open clusters like that one and M37 in Auriga. If you want a supernova remnant, then M1 in Taurus is near a naked eye star and should be bright enough to see (I can with a 4 inch in Bortle 4). If you want to try galaxies, the Leo Triplet are fairly easy to find. It might take you a while to get your eye in. The faint stuff like galaxies are pretty faint. It still takes me a while to get my galaxy eyes in. A lot of the time I'm looking for a patch of sky that isn't quite as dark as the rest. I wouldn't notice it if I didn't spend time at the eyepiece waiting for it to come.

Good luck and welcome to the forum.

  • Thanks 1
Link to post
Share on other sites

Hello, I have a 10" dob too.  Do you have stellarium or something similar? I live by stellarium, a telrad, 9x50 right angle finder and a pair of 10x50 bins. Research the brightest DSOs to start with too. Good luck, it will come with practise.

  • Like 1
  • Thanks 1
Link to post
Share on other sites

One important thing to learn when you're using a telescope is the surface brightness of deep-sky objects. This is a number that represents how bright that object is. Counter-intuitive, a larger number means a fainter object. The Orion Nebula has a low surface brightness 'number' and is therefore very bright. I assume you mean IC 443 with The Jellyfish Nebula, if so, this is a very faint nebula from the IC catalogue. It may be visible with your scope, but don't expect anything bright and eye-catching like the Orion Nebula.

Best is to start with objects from the Messier catalogue (starting with an M, like the ones @domstar suggests). These are usually the brightest and are mostly easy to find. The light pollution filter is not very helpful (or useless, depending on who you ask). Here is a useful chart that orders the Messier objects by difficulty: begin with the green ones and work your way down to see how many you can find. Good luck!

  • Like 3
  • Thanks 1
Link to post
Share on other sites

Just to follow what the others have correctly suggested. If you haven't already, think about getting the book "Turn Left at Orion". It is a great introduction to finding targets, including DSO, with plenty of diagrams showing you what to expect - and specifically covers scopes like yours.

Lots of good DSO targets coming up this spring. Globular clusters, brighter galaxies, planetary nebula. Your 10" in Bortle 5 will be great.

https://www.firstlightoptics.com/books/turn-left-at-orion-book.html

  • Thanks 1
Link to post
Share on other sites

Most DSOs are very faint even for a 10” mirror. By far the best tool is the book Turn left at Orion. I strongly recommend you purchase that and use it as your guide when observing. Remove the light pollution filter too.

  • Like 2
  • Thanks 1
Link to post
Share on other sites

If you are looking for galaxies and clusters I would take the filter off the eyepiece. It won't improve your chances.

Leo and Virgo are teeming with galaxies that your scope will show but most are faint targets. Make sure your eyes are dark adapted as much as possible.

The Orion Nebula rather spoils us I'm afraid because it is so large and bright.

Edited by John
  • Like 3
  • Thanks 1
Link to post
Share on other sites

I've managed a good few DSOs from my bortle 5 garden with a 150 dob, so don't give up !

I'd try without the filter, I'm not convinced they are effective with modern LED street lights.

Do allow plenty of time for your eyes to dark adapt : I need about half an hour, but it varies from person to person. Only use a very dim red light if absolutely needed for tasks (to be honest, in bortle 5 the sky glow is usually enough for most purposes !) Even a moment's bright light will mean you have to start your dark adaptation all over again.

Train yourself to use averted vision, looking to the side of the place of interest. This allows the more low light sensitive parts of the eye to do their thing (our central view is tuned for colour vision, not low light vision) If you have binoculars (no need to be expensive, big or powerful ones) try scanning the target area with them, and try the averted vision trick while using them too , it works !

Abandon faint DSO hunting if there is bright moonlight swamping the sky. In those conditions I go with the flow and become a lunar observer.

Three nice easy targets I saw recently from the garden in my 150mm, and then just for fun tried for and found with my second hand bargain basement 80mm short tube refractor are M 36 , 37 and 38, all open clusters in Auriga , quite high in my southern sky last week. I like the starfish cluster best, because it really does look like a starfish !

https://www.messier-objects.com/messier-38-starfish-cluster/

Heather

 

  • Like 4
  • Thanks 1
Link to post
Share on other sites

This site is a few years old, but has some useful insights http://washedoutastronomy.com/washedoutastronomy.com/content/urban-galaxies/index.html

And I've posted a link to the Loughton list several times in the past, one more can't hurt : think of it as a free printable to keep you busy until you can get a copy of the excellent ' turn left at Orion' . You don't give a location, so I have no idea if the fact it has UK season references is a good thing for you or not .

https://las-astro.org.uk/docs/Loughton_List_v2_0.pdf

  • Like 3
  • Thanks 2
Link to post
Share on other sites
21 hours ago, Tiny Clanger said:

This site is a few years old, but has some useful insights http://washedoutastronomy.com/washedoutastronomy.com/content/urban-galaxies/index.html

And I've posted a link to the Loughton list several times in the past, one more can't hurt : think of it as a free printable to keep you busy until you can get a copy of the excellent ' turn left at Orion' . You don't give a location, so I have no idea if the fact it has UK season references is a good thing for you or not .

https://las-astro.org.uk/docs/Loughton_List_v2_0.pdf

I'm in the UK, thanks for this 

  • Like 1
Link to post
Share on other sites

Looking for objects of low surface brightness from an urban area is rather a waste of time.  I have seen galaxies, a few nebulae and planetaries from my suburban site, but they were all high surface brightness objects and I saw far more from rural Devon.

Interestingly, I tried EEVA with a smaller scope (102mm) from home and was astonished to find that it revealed as much as a scope twice the size used visually at a dark skies site.  It revealed the Crab nebula (M1) and M33, and the Veil nebula (just), none of which I have ever seen visually at all.

  • Thanks 1
Link to post
Share on other sites

I'd give my left hand for bortle 5! Keep trying. As said above, avoid diffuse nebulae for the moment. Often they require UHC or OIII filters to make them pop out anyway.

Concentrate on DSOs that are relatively easy to find. M81 and M82 are perfect starter galaxies.  I've viewed those two many times under bortle 8 skies with several small telescopes.

As spring arrives the Leo Triplet is a good test. As are planetary nebula - The Ring and Dumbbell. The globulars - M3, M92 and M13.

Don't neglect double star systems either. The 10" will make many splits easy.

To reiterate, start with the objects you know, once you're able to find them, you should be able to see on a good night with a 10" under bortle 5. Then aim for the harder targets.

Urban observing - Start low, aim high, become disappointed and buy a tent.

Edited by ScouseSpaceCadet
  • Like 4
  • Thanks 1
Link to post
Share on other sites
On 07/03/2021 at 08:26, domstar said:

Jellyfish Nebula is incredibly faint and more of a target for photographers- I couldn't find a magnitude for it. 

Mag. 12 according to Stellarium, so it's very faint.

To put in perspective I was shooting this a few weeks ago and using exposures of 5 mins (albeit in Ha) and even then the images are still quite faint.

  • Like 1
Link to post
Share on other sites
On 07/03/2021 at 08:23, Spile said:

Not everyone agrees with the "rankings" but this is quite fun...

messier objects ranked by viewing difficulty

Oh this table is great, thanks for posting!

Link to post
Share on other sites

Try to make sure your eyes are dark adapted as well. Any stray light will also spoil your views as well; a few nights ago, i was out observing nebulas and my wife turned the lights on in the sitting room and i could not find anything, as soon as that light went off i could find the faint smudges. Try practice using your averted vision, many of these faint objects are hard to see. An easy DSO  is M97 and M1, not much star hoping and ok even with some moon light. Try pick some easy targets. The Leo galaxies are also easy to spot. I also found with DSOs that any high altitude thin clouds/mist will make it nearly impossible to find them. Since you mentioned nebulas, quite a few of them are the size of a 5p coin in the EP so the Orion is spoiling us, so do not expect that brightness and size. Try use a low EP magnification to locate them and then move to a bit higher. Worth taking a look at the Observing Reports or Deep sky in this forum for ideas on targets. Turn Left at Orion is good to get a feeling on how things will look, it is pretty spot on with my 8" Dob.

Edited by Kon
  • Like 1
  • Thanks 1
Link to post
Share on other sites

I agree that M36, 37 and 38 are good targets I also like M41,46,47, and 48. And my recent favorite is the beautiful double cluster NGC 869/884.  Those are just the ones I’ve recently viewed in bortle 8 with 10” dob. Sky safari is a great app to use it’s my right hand when I’m observing. Great advice given by everyone else. Good

luck!

  • Thanks 1
Link to post
Share on other sites

I started out with a 10" dob, and it's a great instrument!

I had read that you "learn to see".  I couldn't understand what that meant initially, but it is so true.

If it's any consolation,  M31 Andromeda was my 1st galaxy.  It took me 5 nights of trying before I found it!  😂 Later though, as I learned more about the scope, conditions and observing, I'd see much more detail - several dust lanes, companion galaxies...

It takes a bit of patience,  but very worth it.  Atmospheric conditions can greatly influence things from night to night, as does the elevation of the target and the darkness of the skies.

  • Like 1
  • Thanks 1
Link to post
Share on other sites

All the above is sound advice.

Try the easiest items on the messier list, refine your vision by finding the fainter satellites around Saturn

For the brighter objects you shouldn't need a LP filter, but once you have found one, try with and without filter.

Naturally always use your lowest power EP first. See-ing is a skill that is learnt

  • Thanks 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.