Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

DSO observations from a light polluted sky.

beginner dob dso observing reflector
  • Please log in to reply
57 replies to this topic

#1 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 12:01 AM

It’s hard to find visual examples of how DSO's look like under heavy light polluted skies.(I couldn’t find many)

 

Aside from some excellent writing and a few sketches, there's not so much visual information of how you really see those objects. (Probably there are excellent books, but not everybody has them.)

 

This may lead to some frustration on people that live in those places like me, because it’s hard to detect and watch, most of the time with averted vision, those faint DSO’s. And when you think you see them, you don’t know how they look like. On this quest I have to rely on my eyes, on some software, on info that I can find here on the Forum or on the Web.

 

Based on this I've decided to start this topic, to show how I see several DSO's using images made with software help.

 

For now, all observations will be made with a F/6 reflector Dob and a 25mm SP eyepiece.

I got this Dob with the help of the guys here at the Cloudy Nights Forum. With those precious hints and tips, I found the best available Telescope to my limited budget. For this I will always be grateful...

 

All the observations are from my facing West balcony, which has a FOV from about 180º towards South(left), 300º towards North(right) and about 70º Altitude, so I will only post images of views from this spot.

 

gallery_304439_10528_56863.jpg

 

As you see, the conditions are bad, obfuscating street lights to the right, in front white buildings and on the left a building that also reflects light.

 

Here is the data according to lightpollutionmap.info.

 

gallery_304439_10528_282269.jpg

 

gallery_304439_10528_17807.jpg

 

Bright as hell...sad.png

 

First I had to Mod my Telescope. I built an Azimuth and an Altitude Angle scale to help locating, otherwise it would take forever to find those objects. As other fellow white zone stargazers know, star hopping is not an easy thing to do on these places.

Then I built a barrier to avoid those annoying street lamps to the right, and kept all the lights off inside my house. Besides this efforts, there’s not much more I can do to achieve ideal night vision.

 

I don't have any drawing skills to make sketches, so all the images are made using Stellarium.

I’ve managed light pollution and refraction/Extinction parameters to get the most approximate possible views of what I saw.

I’d say that they are pretty close, but of course real views are clearer and sharper.

Keep in mind that screen brightness and contrast may vary from user to user. Adjust it till you see the object. All objects are on the center of the eyepiece. You must use averted vision if you can’t see the object, especially on galaxies.

 

Here is an example of how the observation images will look like. That’s the Open Star Cluster M67 as I saw it, with good sky conditions.

 

gallery_304439_10942_30611.jpg

 

All the images have, to the top right the Stellarium info about Scope, Eyepiece used, etc., and bellow that some data about when and how the DSO was seen by me.

 

I hope that these observations will give, to all those fellow beginners, a visual aid, a glimpse of what we can expect to see under these bright skies.

 

Alexandre


Edited by alexantos, 18 March 2019 - 12:05 AM.

  • Inkswitch, rustynpp, JKAstro and 4 others like this

#2 Araguaia

Araguaia

    Apollo

  • *****
  • Posts: 1480
  • Joined: 31 Aug 2018
  • Loc: deepest, darkest Brazil

Posted 18 March 2019 - 04:40 AM

Great project!  M67 looks realistic - parebéns!  I see it that way when the Moon is out.

 

But do take the telescope to a dark site sometime, and brace yourself so that you don't fall backwards in awe when looking at the same objects!


  • NYJohn S and alexantos like this

#3 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 03:52 PM

Great project!  M67 looks realistic - parebéns!  I see it that way when the Moon is out.

 

But do take the telescope to a dark site sometime, and brace yourself so that you don't fall backwards in awe when looking at the same objects!

Thanks (Obrigado) for the feedback.

 

I'm planning to go to this observatory, and spend a week there. Maybe late June or early July.

I also have a spot, near my mom's house, where I use to look at the sky with binos. This time I'll have a scope.waytogo.gif

But this month, and probably the next, I don't have the time...frown.gif

Meanwhile I'll continue my observations here. There's a lot of sky learning to do.

 

Take care (Fica bem)


Edited by alexantos, 18 March 2019 - 04:34 PM.

  • Araguaia likes this

#4 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 04:30 PM

Globular Clusters M-3 and M53

 

I'd say that somehow I was a bit disappointed when I saw this two objects for the first time with my scope.

I had this idea that because of huge star concentration, this objects were really bright, even when seen from my place. Unfortunately that's not the case.

 

M-3 is a bit brighter and bigger than M-53, but both are rather diffuse.

M-53 is harder to see. From here looks like a faint galactic core. M-3 looks like a gray cotton ball, or a cocoon from a silkworm.

On both objects I couldn't resolve any stars, even at 101x.

 

This is how I see them from here.

 

gallery_304439_10942_12511.jpg

 

gallery_304439_10942_41660.jpg


Edited by alexantos, 18 March 2019 - 05:37 PM.

  • NYJohn S likes this

#5 Araguaia

Araguaia

    Apollo

  • *****
  • Posts: 1480
  • Joined: 31 Aug 2018
  • Loc: deepest, darkest Brazil

Posted 18 March 2019 - 04:53 PM

M3 is one of the less bright globs.  Have you seen M13 or M22?



#6 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 05:03 PM

M3 is one of the less bright globs.  Have you seen M13 or M22?

Both M13 and M22 are out of my balcony FOV right now. Only by May/June I'll be able to see them.



#7 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 79596
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 18 March 2019 - 05:08 PM

There are perhaps 180 or more globular clusters in the Milky Way.  Twenty-nine of them are Messier objects.  M22 is the brightest at magnitude 5.2 and M72 is the faintest at magnitude 9.3.  (Magnitudes will vary slightly according to the source.)

At magnitude 6.3, M3 is in a four-way tie. along with M15, M55, and NGC 6541, for being the eleventh brightest so it's not exactly one of the less bright globulars.  It can be easily seen with small binoculars and is visible to the naked eye for some observers.

 

http://ngcicproject....pers/gctext.htm

 

Dave Mitsky


  • NYJohn S likes this

#8 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 05:33 PM

There are perhaps 180 or more globular clusters in the Milky Way.  At magnitude 6.3, M3 is in a four-way tie. along with M15, M55, and NGC 6541, for being the eleventh brightest so it's not exactly one of the less bright globulars.  It can be easily seen with small binoculars and is visible to the naked eye for some observers.

 

http://ngcicproject....pers/gctext.htm

 

Dave Mitsky

Thanks for the link Dave.

 

I've tried to see NGC 5466, the Snow-globe cluster, that has 9,2 magnitude according to the list, but I couldn't, not even averted.

I can see some galaxies with similar magnitudes, most of them using averted vision, so I thought that it was possible.

Probably it has to do with his size or low surface brightness.



#9 havasman

havasman

    Cosmos

  • ****-
  • Posts: 9431
  • Joined: 04 Aug 2013
  • Loc: Dallas, Texas

Posted 18 March 2019 - 05:36 PM

It's just a personal preference but I find open clusters more rewarding from my light polluted home observing site.

 

I had an interesting observation of M93 last week. Due to the very poor conditions, all the fainter stars are hidden in the brightness and a close replica of the trapezium stars in M42 stood out clearly, roughly in-line with the two brightest and yellow-ish stars in the cluster. I had not previously noticed these 4 and had likely not observed M93 from here before.

 

Whereas globulars are just diminished by poor conditions, open clusters can be changed and offer new perspectives.

 

Certainly the best observing is from dark sky conditions but if you're going to look from home I recommend OC's.


Edited by havasman, 18 March 2019 - 05:37 PM.

  • Inkswitch, WyattDavis, Astro-Master and 2 others like this

#10 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 18 March 2019 - 06:37 PM

It's just a personal preference but I find open clusters more rewarding from my light polluted home observing site.

 

I had an interesting observation of M93 last week. Due to the very poor conditions, all the fainter stars are hidden in the brightness and a close replica of the trapezium stars in M42 stood out clearly, roughly in-line with the two brightest and yellow-ish stars in the cluster. I had not previously noticed these 4 and had likely not observed M93 from here before.

 

 

Here is how I see M-93 from my location.

 

What you mean is those two bright stars nearly at the top. If so, I've marked the place were I presume the trapezium is.

Next time I watch, I'll look for it.

 

Thanks for the tip havasman.

 

 

gallery_304439_10942_16527.jpg


  • ThousandRivets likes this

#11 havasman

havasman

    Cosmos

  • ****-
  • Posts: 9431
  • Joined: 04 Aug 2013
  • Loc: Dallas, Texas

Posted 18 March 2019 - 07:03 PM

Yes, those are likely the stars I referenced. I was at higher magnification (not noted but probably 137x and 44 arc' field) and there were significantly fewer stars seen overall in the cluster so that those relatively bright ones stood out even more than in your simulation.


  • alexantos likes this

#12 AxelB

AxelB

    Apollo

  • -----
  • Posts: 1418
  • Joined: 22 Mar 2015

Posted 18 March 2019 - 07:08 PM

You absolutely need a 6mm eyepiece (+/- 1mm) with wide apparent field. It will allow optimal magnification, which will darken sky background. Watch the classified for something like a Meade 5000 5.5mm. These can sometimes be found at a good price and the performance is excellent. Such sn eyepiece will completely transform your appreciation of globular clusters. With a 25mm, you can barely detect these. With a 5.5, you would resolve stars and get up close and personal with your target. It will also be great for moon and planets.

Of course as other said, you’ll need to travel to darker sky to really discover DSOs but I understand there’s some pleasure to be had even under less than optimal conditions (I mostly observe from my red zone backyard).
  • Inkswitch and NYJohn S like this

#13 Araguaia

Araguaia

    Apollo

  • *****
  • Posts: 1480
  • Joined: 31 Aug 2018
  • Loc: deepest, darkest Brazil

Posted 19 March 2019 - 04:20 AM


At magnitude 6.3, M3 is in a four-way tie. along with M15, M55, and NGC 6541, for being the eleventh brightest so it's not exactly one of the less bright globulars.  It can be easily seen with small binoculars and is visible to the naked eye for some observers.

 

 

Despite this, to me M15 looks much... I don't know... brighter than M3?  For one thing I can see M15 by naked eye easily, but never M3.  For another M15 looks a lot better aesthetically through the eyepiece.  Perhaps because its core is so tight and packed with stars.

 

I am learning that even for non-nebular objects the apparent magnitude figure is just a rough guide for how it looks and how easy it is to find.

 

NGC 6541 is another one that beats M3, in my opinion - but in this case it is because of the bright HII regions all around it in Corona Australis.  I love this part of the sky.

 

Finally, alexsantos could go to the Algarve, find a point with a view south and shelter from all the condo lights (maybe it will get darker after Brexit? laugh.gif ), and have a look at Omega Centauri, which is coming into season now.  



#14 Tony Flanders

Tony Flanders

    Hubble

  • *****
  • Posts: 16871
  • Joined: 18 May 2006
  • Loc: Cambridge, MA, USA

Posted 19 March 2019 - 05:48 AM

Despite this, to me M15 looks much... I don't know... brighter than M3?  For one thing I can see M15 by naked eye easily, but never M3.  For another M15 looks a lot better aesthetically through the eyepiece.  Perhaps because its core is so tight and packed with stars.

M3 is much more luminous than M15, but also quite a bit farther away. M15's proximity makes it much easier to resolve the individual stars through a modest-sized telescope. But through a really big telescope, the fact that M3 has many more stars overall becomes apparent.

 

And yes, M15 has an abnormally dense core, having undergone what is technically described as "core collapse."


  • Araguaia likes this

#15 jcj380

jcj380

    Apollo

  • *****
  • Posts: 1438
  • Joined: 08 Jul 2014
  • Loc: 42N 88W

Posted 19 March 2019 - 07:23 AM

Globular Clusters M-3 and M53

 

I'd say that somehow I was a bit disappointed when I saw this two objects for the first time with my scope.

I had this idea that because of huge star concentration, this objects were really bright, even when seen from my place. Unfortunately that's not the case.

 

M-3 is a bit brighter and bigger than M-53, but both are rather diffuse.

M-53 is harder to see. From here looks like a faint galactic core. M-3 looks like a gray cotton ball, or a cocoon from a silkworm.

On both objects I couldn't resolve any stars, even at 101x.

Your sketches are pretty good representations of what I see from home.  I sometimes get some resolution on some globulars but that's not typical.  "Gray cotton ball" is what I usually see.

 

I agree with havasman that open clusters are much more rewarding in heavy LP / full moon / etc.  Fainter globulars and most Messier galaxies are on my darker site observing list.


  • alexantos likes this

#16 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 19 March 2019 - 06:15 PM

Open Star Clusters M-36, M37 and M38.

 

Just a couple of hours ago I observed these 3 clusters. I had to rush because the moon was coming...

They are pretty much at the same location in Auriga.

 

M37 looks dim with a soft fuzzy glow. Maybe that's because of his 6,2 mag or high star concentration towards the center. Of the three he is suppose to be the brightest.

 

M36 have more disperse stars, but brighter ones in comparison with M37. It has a mag of 6,3. It has no glow but have some peculiar stars at the center.

 

M38 wins the prize. Of the three and or me, it's more enjoyable to see. Maybe it's because the stars are more disperse and I can resolve a lot of the smaller ones. Also no glow at all. It has a mag of 7.4.

 

 

gallery_304439_10942_20125.jpg

 

gallery_304439_10942_13338.jpg

 

gallery_304439_10942_32373.jpg


  • Anthony236J and jcj380 like this

#17 jcj380

jcj380

    Apollo

  • *****
  • Posts: 1438
  • Joined: 08 Jul 2014
  • Loc: 42N 88W

Posted 20 March 2019 - 07:30 AM

M36 is easy and my favorite, M38 is a little tougher, and M37 can be somewhat difficult IME.

 

Great sketches!



#18 ziridava

ziridava

    Viking 1

  • -----
  • Posts: 811
  • Joined: 17 Aug 2012

Posted 20 March 2019 - 09:23 AM

Last year only three times  (no Moon'' - spare time - friends to join -good weather)  went together.

Doing observations only three times would mean a very poor astronomer.

Doing observations from home helped me to see much more.

I made a quick counting and it seem I made at least 130 observations last year,most from home.

My place is at ten minutes walking distance from the downtown of  a +190.000 city.

However , one should not think I saw only the Moon , Albireo,Coathanger and a few other bright ,easy objects.

I saw many times Veil Nebula , the bright part of North America /NGC 7000 Nebula , Helix Nebula and dozens of galaxies and clusters.

 

alexantos 

 

Congratulations for starting this topic.

 

Using the informations on Mel Bartels site I suggest to check the size of what he call ''secondary baffle'' of your telescope.

For a solid tube telescope (like ours ) this translate into twice the distance  from the focuser axis to the mouth of the tube.

To me , for an Urban Guerilla Telescope , it seem a bit too short.

Probably an extension like a dew cap will help to reduce glare and increase contrast.

 

From the same source , I suggest to add ,if it is not already in place , a ''focuser   baffle''.

This help even more to increase contrast.

 

I bought a zoom eyepiece , it is very helpful.

I use low power oculars only for eyepiece hopping.

I watch DSO at magnifications of at least 100x ,usually 154x ,the maximum provided by the zoom ocular.

 

Please keep on posting , you will have a loyal reader here, Ziridava


  • alexantos likes this

#19 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 20 March 2019 - 11:32 AM

(...)Congratulations for starting this topic.

 

Probably an extension like a dew cap will help to reduce glare and increase contrast.

 

From the same source , I suggest to add ,if it is not already in place , a ''focuser   baffle''.

This help even more to increase contrast.

 

I bought a zoom eyepiece , it is very helpful.

I use low power oculars only for eyepiece hopping.

I watch DSO at magnifications of at least 100x ,usually 154x ,the maximum provided by the zoom ocular.

 

Please keep on posting , you will have a loyal reader here, Ziridava(...)

Hey ziridava,

 

Thank you for your kind words.

 

I'm already building a Dew Cap. Maybe next weekend will be done.

 

The scope inside is covered with non reflecting material. The edges and side of the secondary are blackened. The only thing that is missing is the focuser baffle. Thanks for the tip.

 

For now I plan to buy a 6mm WA eyepiece and a Barlow. You see, cheaper 1,25" zoom eyepieces have a very narrow aFOV and the wider ones are too expensive for me. I'm not saying that zoom eyepieces are not practical, or useful or sharp. I'm sure they are. But right now, and as a beginner with a lot of sky learning to do, I'm going for those WA eyepieces.

 

Posting as much observations as I can is the plan.

Thank you for following.

 

Take care,

Alexandre



#20 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 20 March 2019 - 12:18 PM

Open Star Clusters NGC-2169, NGC-2244, NGC-2264 and NGC-2301.

 

NGC-2169 (mag 5,9) is in the Orion constellation. It's on the club region near the stars 67 Ori and 70 Ori. It is called the 37 Cluster but unfortunately I can't see all the stars that resemble the number. Nevertheless is a nice asterism to see.

 

The next three OSC are in the Monoceros constellation.

 

NGC-2244 is in the middle of the Rosette Nebula. I can see only a few stars and no nebula at all, in spite of having a mag of 4,8, it is the least spectacular object

 

NGC-2264 (mag 3,9) can be the Cone Nebula or the Christmas Tree Cluster, Like the previous object, no nebula can be seen but the Star Cluster is very distinct and beautiful to watch. I can see clearly the Christmas tree contour.

 

NGC-2301 offers the best views for me. It has a faint glow at the core and I can see a lot of the smaller stars around. It's the "darker" object of the four, with a mag of 6, but for me it's the brighter, maybe because of the high number of stars that I can see.

 

gallery_304439_10942_23354.jpg

 

gallery_304439_10942_20673.jpg

 

gallery_304439_10942_17179.jpg

 

gallery_304439_10942_7400.jpg


  • payner and Anthony236J like this

#21 ziridava

ziridava

    Viking 1

  • -----
  • Posts: 811
  • Joined: 17 Aug 2012

Posted 21 March 2019 - 09:31 AM

You are welcome and good luck at further optimisations of your nice telescope ,they will pay dividends latter.

The Seben 8-24mm zoom ,available in Europe , have 60 degrees field at 8mm.

At 24mm ,you are right , the Seben zoom  have only 40 degrees field, this is why when the zoom is inserted,the object or target field should be already centered with a wide field ocular.

This is now my current routine.

But once inserted , you can choose that magnification which give you the best view.

This is especially helpful when working with filters.

Cannot be done with fix focus oculars.

 

Clear sky , Ziridava


  • alexantos likes this

#22 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 25 March 2019 - 07:56 PM

Open Star Clusters M35, M44, M47, M48 and M50.

 

M35 is in Gemini. It has a mag. of 5,1. I can see averted a faint glow in the center.

 

M44 is in Cancer. It has a mag. of 3,1. Lot's of bright stars in this wide cluster.

 

M47 is in the Puppis constellation with a 4,2 mag. The stars in the center form a cross shaped pattern

 

M48 is in Hydra. It has a mag.5,5. There's a perceptible dim glow in the center that is visible with direct vision.

 

M50 in Monoceros with a 5,9 mag. It is the "darkest" of this 5. Despite this, I can see a faint glow in the center.

 

 

gallery_304439_10942_2275.jpg

 

gallery_304439_10942_37253.jpg

 

gallery_304439_10942_22051.jpg

 

gallery_304439_10942_11460.jpg

 

gallery_304439_10942_2374.jpg


  • REC, ziridava and Anthony236J like this

#23 alexantos

alexantos

    Vostok 1

  • -----
  • topic starter
  • Posts: 121
  • Joined: 05 Jan 2019
  • Loc: Estoril, PT (White Zone)

Posted 26 March 2019 - 03:27 PM

Galaxies NGC 2683, NGC 2841, NGC 2903 and NGC 3521.

 

Galaxies are the most difficult objects that can be seen under this awful conditions.

 

Most of the time I can't see almost no traces of this fuzzies at all. To be able to see something, frequently with averted vision, I need very good or excellent sky conditions.

 

First, I have to check the star patterns around those galaxies to locate the exact spot were they suppose to be. Next, and when I'm sure of their exact spot, I start to look, alternating averted and direct, and I move the Telescope around a little bit. Then those faint cores start slowly to come out, and then can be seen.

 

During this month, I had some stable clear skies, with almost no turbulence at all. I compare sky conditions by looking at M42 and see how bright it is and how many details can be seen.

 

Two of those nights were the 10th and the 11th of march.

 

NGC 2683 in Lynx, known as the UFO galaxy, a spiral galaxy with an apparent magnitude of 10,6, was an object that I thought it was hard to see. But it wasn't. Almost immediately, as I spotted the trapezium star pattern to the right, I saw the faint core. You can't miss. It looks like a small faint dash in the sky. Truly marvelous.

 

NGC 2841 is a spiral galaxy, mag. 10,1, located in Ursa Major. I only could see the faint core after looking for a while. It was not easy...

 

NGC 2903 is also a spiral galaxy, located in Leo and with a mag.of 9,7. The star patterns around makes it easy to locate, but seeing it, is another thing. It took some time to see it averted, but there it was...

 

NGC 3521, another spiral galaxy, located in Hydra with a mag. 10, was somehow easy to see. It's not the brightest of this four, but the faint core detached almost immediately as I found his spot in the sky.

 

 

gallery_304439_10942_40008.jpg

 

gallery_304439_10942_33013.jpg

 

gallery_304439_10942_6161.jpg

 

gallery_304439_10942_25657.jpg


  • Anthony236J likes this

#24 allen g

allen g

    Explorer 1

  • -----
  • Posts: 97
  • Joined: 29 Jul 2013
  • Loc: Los Angeles, CA

Posted 26 March 2019 - 09:38 PM

thanks for starting this thread - have you seen this book "The Urban Astronomer's guide" by Rod Mollise - Springer books
I found it very helpful and photos are included. Enjoy your scope.
  • alexantos likes this

#25 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 79596
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 27 March 2019 - 12:46 PM

There's a section on urban astronomy near the end of my post (#22) at https://www.cloudyni...mers/?p=5184287




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: beginner, dob, dso, observing, reflector



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics