August Challenge Object - Gamma Delphinus

[iceman]

Hi all.

We'd love you to take part in the August Observing and Imaging Challenge (http://www.iceinspace.com.au/index.php?id=69,224,0,0,1,0). Please post your reports, sketches and deep-space images of Gamma Delphinus in this thread. Discussions about the images can also be in this thread.

Please ensure the images obey the posting guidelines when you attach them.

While it would be nice if the report, sketch or image were taken in the month of August, it's not essential so feel free to post older reports and images if you're unable to take some new ones.

We look forward to seeing your contributions!

[Orion]

This is my effort on the double Gamma Delphinus (HR 7948-7947).
30 x 1/2sec, DSI camera, 18" telescope. Stacked in Registax.
I like the color of the secondary in this double.

[Mick]

Star: Gamma Delphinus
Location of site: Mackay Lat 21.08
Date & Time: 09/07/05 21:07
Sky conditions: 6/10
Telescope: Meade Lx90
Eyepiece: Meade Sp 26mm (77x)

Gamma Delphinus is a beautiful double star with a golden yellow primary and a white/grey secondary very easy to split using lower power. It is one of those doubles that sucks you in, so striking in colour and appearance. The secondary was most interesting; I have read that observers have seen a range of colours in the secondary green, blue and pale yellow. I found the following story about Gamma Delphinus and Aboriginal Astronomy whilst surfing the net at this link The Sun and Moon– some Aboriginal perspectives and activities (http://64.233.179.104/search?q=cache:6oMeQpP0taoJ:www.abo riginaleducation.sa.edu.au/files/links/The_Sun_and_Moon_Aborigin_1.pdf+Abo riginal+astronomy+constellations+Ot chocut&hl=en)



"The Murray Cod is known as Otchocut by the Boorong people and is represented in the sky by the Delphinus (the dolphin) constellation. Gamma Delphinus is golden and yellow-white, the same colours as the flanks of the Murray cod. The disappearance of the Otchocut constellation from the sky after September to October coincides with the end of the spawning season for the Murray cod. When Otchocut is in the sky, you should not fish for Murray Cod because they are breeding"

[atalas]

Yeah !thanks for the shot of Gamma Delphinus Ed ,been dying to see a shot of It. Trees block my view at home so I haven't been able to check it out as yet.Mick thanks for the interesting story !

Louie :thumbsup:

[beren]

:thumbsup: Interesting link Mick . Beautiful double star , easily resolved with a 80mm refractor+ 22mm eyepiece yeilding 27x but best seen with a 250mm SCT at F/10 using a 14mm eyepiece {178x} , striking yellow primary and a off- white secondary that to my eyes had a a grey tinge :confuse3:

[Mick]

I'm glad you see grey in the secondary as well beren, I felt a bit silly at first saying White/Grey. :)

[ausastronomer]

Nice shot Ed and nice reports guys. I occasionally see grey in the secondary but not often. As I described in the write-up I usually see it as yellow/white and sometimes having an emerald hue, but that can also be due to ones own interpretation of colour.

On a different note, Mike and Andrew Durrick were keen to use Albireo (Beta Cygni) as next months double star challenge. I am not so keen to do that, as its a case of everyone been there done that, so to speak. Would you guys (who have shown an interest in the double stars) like to run with Albireo or would you prefer me to pick a lesser known interesting target from my memory banks that may be new to a lot of people ?

CS-John B

[gaa_ian]

Perhaps the double Double in Lyra ?
It is an easy wide double, but splitting each into a double is a bit of a challenge.

[astro_south]

I suggested that but it might be a bit tough for those right down south!

[ausastronomer]

Yup ε Lyra (Double Double) is tough from Southern Australia in smaller scopes.

What I was actually suggesting was, "would you like me to use Albireo, or pick an interesting target that you've probably never looked at before ?"

CS-John B

[astro_south]

I definitely vote for the never looked at before. Their maybe some noobs on the forums who have never seen Albireo, but I'm always open to an unknown (to me) gem as Gamma Delphinus was.

[Orion]

I'd like a double with two color variations, not to low in the horizon if at all possible.

Is that asking to much? :confused:

[gaa_ian]

OK ...surprize me :love:

[Mick]

Maybe September is a bit late for this double but how about 95 Herculis?

[ausastronomer]

Mick,

I thought about 95 Herculis, also Rasalgethi (α Herculis) which is also a nice colour contrast double, with the secondary sometimes appearing green. Problem being, for our friends in Southern Australia and New Zealand they will be very low, particularly 95 Herculis being about 6 or 7 degrees North West of Raselgethi. A couple of others I was also thinking of were H N 84 in Sagitta which shows a nice colour contrast and also 21 Sagittarii which is a lovely colour contrast double and also shows a marked difference in size and magnitude between the primary and secondary, unfortunately the current separation is 1.5" @ 275 deg meaning you need very good optics, a fair sized scope and exceptional seeing conditions to split it, the reward is there when you do !! Unfortunately its beyond smaller scopes. Considering all the factors I was proposing to select something from the area around Aquarius, Capricornus or Aquila, which will be accessible for all Southern Hemisphere members, they contain some lovely doubles, many of which people may not have seen before.

CS-John B

[Mick]

Had a good look at 95 Herculis (Chameleon) tonight stunning gold and silver to my eye, I'd love to see red and green in it but as hard as I looked I couldn't. Using a 12" f/5 dob best views were at 156x. 57 Aquilae and 94 Aquarii are nice doubles. Sorry if this is OT in this thread.

[davidpretorius]

Seeing: III

Transparency: 5/7 thanks to moon

Magnification: 1250/6 = 208 X at F5

Toucam: brightness 50%, gamma 0, saturation 100%, fps 25, gain 80%

First time out for a week thanks to weather and i am happy to say i can add my first image to the challenges.

Video showed up two colours blue and orange, registax did well and i have enlarged aprox 3 times in photoshop, but no processing...

Movis is here (151k) http://www.precons.com/iis/gallery/Movies/20050821-g2d_0000.avi

so here she is:

[Mick]

Now thats different. What a wonderful video David, it sure is a beautiful DS.

[ausastronomer]

Great effort David

CS-John B

[gaa_ian]

OK ... had a look at Gamma Delphinius.
To my Eye it was orange/white & white with a tinge of green.
A nice double, I will be adding this one to my list of Favourite doubles !

[ving]

finally had a look at gamma delph last night. very pretty double aint it!
I got yellowy-orange for the main star and a bluey grey for the secondary in my 10.5mm TV and about the same in my 15mm SV. kinda like daves movie