Observing DSOs with a Skywatcher 150P Newt

[Mark at Beaufort]

I decided to spend the observing night with my 6" Newt to see how it performed on DSOs. In saying that I did start with 'Tegmine' in Cancer to see if I could split the Primary. I used the 6mm Ethos + 2.25x Baader barlow - (mag281x). I watched the system drift across the FOV and from time to time I could see that the Primary was a double.

Moved over to Leo and with the 13mm Ethos (58x) I had a good view of NGC 2903. The next challenge was the Leo Triplet because I wanted to detect NGC3628. Well the FOV of the Ethos gave a nice view of the 3 galaxies.

I moved down to Corvus and using the TeleVue Nebustar and then the Astronomik O-III I was able to detect, although faint, the PN - NGC4361. Two years ago I had the pleasure of using an 18" scope on a mountain top close to the Lick Observatory in California. One of my most enjoyable sights was the Antennae galaxies so I used the 6" to view them again - well no too faint - worth the try.

Virgo was now nicely in position so I started with M98 and M99. I moved down to the start of the Markarian's Chain at M84, then M86, next the 'Eyes'. I ended there because I wanted to use the 12" Dob tonight to view more galaxies along the chain.

Finally I wanted to observe Globular Clusters using the 9mm Myraid and the 6mm Ethos. I started with M53 and whilst in the area had a look at M64. Next target M3, then M5 by which time Hercules was high so I viewed M13 and M92. I decided that the 9mm gave a more enjoyable view at 83x.

So it shows that a Skywatcher 6" Newt can produce the business with a decent dark sky.

 

[John]

Nice report Mark

We both know how well 6 inch scopes can do under dark skies from that great night at Lucksall a few years back.

I feel that I have a gap in my scopes around the 6-8 inch aperture so I might see if I can find a suitable OTA to fill that

 

[Mark at Beaufort]

1 minute ago, John said:

We both know how well 6 inch scopes can do under dark skies from that great night at Lucksall a few years back.

 

Yes John that observing night I spent with you brings back pleasant memories. I always remember the 6" Mak/Newt that you had and FLO allowed me to use a Skywatcher 150PDS.

[RobertI]

Nice report, glad you enjoyed using your scope. 6” is a versatile size for a Newt, especially portable in F5 form - I was after the same scope recently, but ended up getting the F8 version, partly as homage to my old Fullerscopes 6” F8 from the 70’s and partly due to its potential for binaries splitting. I had a similar experience with you on Tegmine during a recent windy session and was surprised by its DSO capability. 

[wookie1965]

That was my first scope and up to now the only one I have ever caught E and F in the Orion Trapezium with cracking scope. 

[Ciaran Meier]

On 14/04/2020 at 13:02, Mark at Beaufort said:

In saying that I did start with 'Tegmine' in Cancer to see if I could split the Primary. I used the 6mm Ethos + 2.25x Baader barlow - (mag281x). I watched the system drift across the FOV and from time to time I could see that the Primary was a double.

Hi Mark

Just want to check with you what was split here.  Was it the A B pair at 1.1" sep.  I've an 8 inch OOUK newt and I reckon 4" is about the best I'm getting with good collimation.  Doubles folk on here seem to go for the frac for this job.  What secret magic are you using to get down to 1" with the 150P 😁.

Ciaran. 

[Mark at Beaufort]

2 hours ago, Ciaran Meier said:

Hi Mark

Just want to check with you what was split here.  Was it the A B pair at 1.1" sep.  I've an 8 inch OOUK newt and I reckon 4" is about the best I'm getting with good collimation.  Doubles folk on here seem to go for the frac for this job.  What secret magic are you using to get down to 1" with the 150P 😁.

Ciaran. 

Hello Ciaran yes it was the main primary star with the close separation. Perhaps it was easier because I had seen it with the 12" scope. However, the attached document from Sissy Haas's book on double stars gives more information on splitting doubles.

[John]

4 hours ago, Ciaran Meier said:

Hi Mark

Just want to check with you what was split here.  Was it the A B pair at 1.1" sep.  I've an 8 inch OOUK newt and I reckon 4" is about the best I'm getting with good collimation.  Doubles folk on here seem to go for the frac for this job.  What secret magic are you using to get down to 1" with the 150P 😁.

Ciaran. 

Can you split the "double double" Epsilon Lyra with your 8 inch OOUK scope ?

Those pairs are 2.3 and 2.4 arc seconds apart respectively and should be a straightforward split for your scope at around 120x magnification.

If you can't split them then either the seeing is poor or the collimation needs adjusting.

Another good "test" double that is better placed right now is Porrima - Gamma Virginis. That pair has a separation of around 2.5 arc seconds.

 

[RobertI]

14 hours ago, Mark at Beaufort said:

Hello Ciaran yes it was the main primary star with the close separation. Perhaps it was easier because I had seen it with the 12" scope. However, the attached document from Sissy Haas's book on double stars gives more information on splitting doubles.

 Very useful table thanks. It’s interesting to note how the difference between the resolving powers is quite large for smaller apertures, but the difference is quite small for larger apertures, surprisingly the 150mm and 200mm are quite close, although I imagine there are some effects of rounding up and down of numbers. 

[Ciaran Meier]

I've plugged in the numbers and come up with WDS 03289+3115 in Perseus.

Aa Ba  0.0m / 0.0m at 1.5" sep. (2005)

So, 1.5" is over twice the seperation achievable at zero delta m for an 8 inch scope.  Will be an interesting experiment for next session. 

Feel free to correct the numbers if necessary 😜. 

 

[John]

Interesting Sky & Telescope piece on "test" double stars and pushing the limits of your scope here:

https://skyandtelescope.org/observing/pushing-limits-a-spring-sky-double-star-romp/

[Ciaran Meier]

Thanks John, great article.  A submission in the comments below the piece (currently the last comment) suggestions that the most favourable conditions are to be had just after sunset and just before sunrise.  I suppose this reduces the background contrast somewhat similar when Observing Venus.