Initial Observations with 12" Dob

[ee001]

As those who have read my initial ‘Welcome’ thread will know I bought a Skywatcher Skyliner 300P Dobsonian back in June. I then took the telescope to southern Turkey (clear skies!), my home country, where I spend my holidays every year. What follows is a brief report of observations made over two months, during July and August.

Before each observation I checked the collimation with a Cheshire.

Saturn and Jupiter (11mm Televue Plossl + 2x Barlow): Unfortunately the rings of Saturn were edge on. On the surface of the planet I could see a lot more detail than my previous 4.5” reflector. Jupiter was more impressive. I could definitely see a lot more surface details/more cloud banding than I ever could with my previous instrument although I could not make out the red spot.

Hercules Globular Cluster: This was a magnificent site, the first time I observed a globular cluster. All the stars were sharply resolved. I came back to this time and time again.

Ring Nebula (11mm Televue Plossl + 2x Barlow): I could clearly make out the ring shape but no other details. I could not make out the central star.

Dumbbell Nebula (11mm Televue Plossl): This simply looked like a faint ball of cloud. I could not really make out its true shape.

M81 and M82: My first galaxy observation. Quite faint and fuzzy. Apart from the general shape I could not make out any details.

Whirlpool Galaxy: This was a disappointment. I was led to believe that with a 12”aperture I would be able to make out the spiral structure. Instead I could hardly see anything! I could see the brightness in the centre and the edge but apart from that I could only just about make out the main body of the galaxy. It was definitely a lot more fainter than M81 and M82.

Viewing conditions: Sky was reasonably dark but not inky black. I could just about make out the milky way. Seeing was not ideal; I could see some flickering around the edges of the planets for example.

So as you see a brief first report. I would like to ask for some advice on how to improve my observations, particularly galaxy observations. Do you think the sky was not dark enough for galaxy observing hence my disappointment? Would using a filter give a significant improvement? What about nebula filters? Would they enable me to see colour in the nebula?

Thanks for any recommendations,

Eralp

[dark knight]

I would hazard a guess that the viewing conditions were less than ideal due to the thermal currents given off by the earth. Turkey is a very warm climate in summer, and all that heat absorbed by the earth in the day time is likely to be released at night, causing turbulence etc.

I'm no expert but an ultra high contrast filter may help with galaxies, I'm sure someone with more knowledge will be along shortly.

[John]

For galaxies I can only really recommend dark skies, practice and patience. The results will come - at the SGL4 star party in APril this year we managed to see lovely views of the spiral arms of M51 in Ursa Major and picked out a mag 13 supernova within another, much fainter, Ursa Major galaxy - both firsts for me. No filters were used - just a well collimated 12" Skywatcher dobsonian scope, dark skies and decent eyepieces. Averted vision (looking to one side of the object rather than straight at it - sort of out of the corner of your eye so to speak) is a good trick to learn as well - I believe our eyes are a bit more sensitive at the edges which is why this works.

John

[mdstuart]

Yes as others have said you need to take time at each object, look to the side and look again and again and again. So take M82 if you ask my 12 year old lad to look he will say I cant really see anything. With a quick look you can see a faint enlogated very dim grey smudge but if you take 15 minutes and use averted vision make sure your eyes are fully adjusted, put a black cloth over your head to get rid of stay light you can then start to make out the shape is irregular and there are darker and light shapes and gaps....

Thats my experience anyway for what its worth.

Mark

[ee001]

Thanks everyone for your advice. Next time I have a chance to observe I will take into account what you've said. The weather will be cooler as well so hopefully seeing will be more ideal.

[Talyn]

Dumbbell Nebula (11mm Televue Plossl): This simply looked like a faint ball of cloud. I could not really make out its true shape.

M81 and M82: My first galaxy observation. Quite faint and fuzzy. Apart from the general shape I could not make out any details.

Whirlpool Galaxy: This was a disappointment. I was led to believe that with a 12”aperture I would be able to make out the spiral structure. Instead I could hardly see anything! I could see the brightness in the centre and the edge but apart from that I could only just about make out the main body of the galaxy. It was definitely a lot more fainter than M81 and M82.

Viewing conditions: Sky was reasonably dark but not inky black. I could just about make out the milky way. Seeing was not ideal; I could see some flickering around the edges of the planets for example.

So as you see a brief first report. I would like to ask for some advice on how to improve my observations, particularly galaxy observations. Eralp

An OIII filter will work on the Dumbell (although you should have seen its shape in the 12" - I have seen the Dumbell shape in an 8") and will help to bring out more detail in it. However, filters of any sort do not work on galaxies.

As for spiral structure in M51, you should be able to see it in the 12". As others have said, using averted vision will help a lot. Also, learning to see detail comes with practice. Less than good skies also have a bearing on this, any haze and galaxies will be washed out. Try increasing the magnification and see if that helps, increased magnification darkens the sky and increases contrast but if the seeing is unsteady this may make the view more 'mushy'.

[Doc]

I'm also very surprised you couldn't see the dumbell shape in the M27. At our recent star party the dumbell shape really stood out, so I would say that your skies are not dark enough or you have not given enough time for your scope to cool down.

An O111 filter might help a bit on the M27 and M57.

But I repeat what others have said, take your time and observe each one for at least 25 minutes. You will be amazed at the detail that pops out with those moments of good seeing.