lunator

Superb video

well done on getting the images.

cheers Ian

Steve, very good pics, especially if the seeing wasn't great 😃

Cheers

Ian

I was inspired by the Sissy Haas book. My only frustration with the book was wasn't good at linking the WDS label with SAO or Bayer/Flamsteed designation so I have tried to provide this information.

I have compiled all my double Star observation into a single book.

I cover some basic concepts of observing double stars and why I observe them but the main resource is my observations of over 2000 doubles.

The book includes:

• A brief overview of double star observing

• A catalogue of 2000+ doubles listed by constellation and them Right Accension.

• Inclusion of all WDS noted companions

• J2000 co-ordinates for handsets

• Precise co-ordinates for all pairs

• Latest WDS PA & SEP (Theta & Rho)

• Brief descriptions to aid identification

• SAO, Bayer, Flamsteed identifiers

• Spectral classes (if known)

• Telescope aperture and magnification used

• A toughness grading allowing you to decide which pairs to observe in the prevailing conditions

The book will be available via FLO very soon.

Cheers

Ian

Good pics Paul., the seeing today was pretty good. The detail on the was impressive

Cheers Ian 

Sounds a good session. I managed to get out with my PST and the ST80 with the solar film and the number of sunspots was amazin.

Cheers

Ian

I wouldn't be without my ST80.

I use it for grab and go on the horizon tripod. It is my white light solar observing scope. I have used it for terrestrial observing when on holiday. The lightness combined with the flexibility means it's a very useful scope. 

Cheers

Ian

I was viewing Mars last night. The seeing wasn't as good as the 16th but the South Pole definitely had the small white dot. 

Cheers

Ian

26 minutes ago, Stu said:

Great image Geof.

I noticed a brightening on the limb marked up here, and also a small spot of brightness at the South Pole. Anyone else see these or was I imagining it?

Stu 

I was looking at Mars last night and could definitely see something at the south pole. The seeing was good for a couple of hours.

Cheers

Ian

Had a short session and thought I would have a try at Jupiter. I am a very occasional imager. The seeing was poor to begin with but just before the fog rolled in it did improve.

OMC250 

ZWO asi120 MC-S

Sharpcap/AutoStakkert and Registax 6 

This is a first pass. 

Cheers

Ian

I was out today but thanks to a reminder I took the hand held solar filter I have with me. I was able to show my wife the eclipse whilst we were out. For once the weather was well behaved ☺️

I had a good view of Jupiter last night. Started with the ST80 and as the seeing was finally good I decided to get the 8" dob out. 

I took the mag up to x240 using the 5mm ortho. The GRS was clearly visible. Several belts were visible. The NEB had a very distinctive darkening to the south of belt. 

Cheers

Ian

Hi Stu 

I would classify them as split. There will always be some black space between the 2 discs of stars as this scenario is at the Raleigh Criteria so the eye can detect a black space as long as seeing permits. 

Cheers

Ian

Over the years I've observed doubles I have found that you can generally apply 3 descriptions .

Round/not resolved

Resolved - clearly 2 stars but no black space between them

Split - A clear black space between them. 

Obviously seeing can make the black space appear and disappear 😊.

If the pair you are looking at is below the Raleigh Criteria which is 138/D at peak response for the human eye then you will not see any back space, but it is still possible to resolve the pair.

Cheers

Ian

Hi @Jimboscotland, I would just like to add my experience with observing doubles.

At present I have 3 scopes. OMC250, Orion Optics 200mm F6 Newt. and an ST80.

The OMC250 gives the best resolution but lives in an observatory I wouldn't want to have to drag it around, it is pretty heavy.

The Newt was originally on an EQ5 and was portable around the garden but was a little unwieldy. It is now on a dob base so is very easy to move around the garden and set up to avoid obstructions. This scope gives fantastic views and combined with a quality eyepiece like an orthoscopic will provide a true colour view.

The ST80 is on a photo tripod. It is very portable, a true grab and go. The colour correction is ok. It does limit the fainter stars in light polluted skies.

Each of these scopes has it's place but if I had to choose one it would be the Newt. I have had it since 2005 and will never sell it. It is a great all-rounder.

Cheers

Ian

Hi Michael, the WDS is accurate for the brighter doubles e.g. Herschel, Strive and South. The later discoveries such as the  Jonckheere pairs can be less accurate when it comes to magnitude. 

I was investigating J252 (if memory serves) and found exactly the same issue. The pair attributed to J252 were faint and quite hard to observe in my 8" scope from London.

Brian Mason at Washington confirmed that Jonckheere doubles are much fainter than listed in the WDS. I don't think that they are updated unless the magnitudes are measured and then published in an accepted Journal. 

For these pairs I add a minimum of 2 magnitudes to the WDS  figure.

Cheers

Ian

Caught one by accident last night. 

Using my 8" dob at x50 whilst viewing a few doubles in Bootes. It was quite bright fast and white. 

Cheers

Ian

Hi Spile

It's a case of fat finger syndrome 😀.

It should read STF2954 a pair with 41" separation. 

Cheers

Ian

Cheers Rusted I will have a look at that.

Continuing my lunar imaging journey I had a go at Gassendi.

Fairly happy with it.

Cheers

Ian

Hi Stu

The accepted view is that anything below the Raleigh criteria shouldn't have a clear split, the definition of this is a clear black line separating the stars.

You can still resolve pairs at the Dawes limit or below. There are several descriptive terms used such as snowmen, figure of eight.

I tend to be more boring and just noted if it is not resolved/resolved or split.

Cheers

Ian

A quick pic of STF333

A close pair but fairly evenly matched.

This is a quick process from one avi frame converted to Jpeg.

Cheers

Ian

Hi Stu

Nice investigation

In my experience at the resolution ratio of 1 (1.16" for your scope you can see pairs upto 2 magnitude differences.

At a resolution ratio of 0.86 (1" in your scope) a delta M of 1,5-1.7 is still possible to see.

Conditions have to be right tho'

Cheers

Ian

Hi Chris it is a tricky one.

I am working out what the scope camera combination can deliver.

I managed to get STF333 last night.

I will post a pic.

Cheers

Ian

I'm a bit old fashioned

The capture was in Sharpcap. The stacking is AS3 and processing is Registax 6. 

cheers

Ian