[Tinderboxsky (Steve)]

Is anyone contributing observations to Sissy Haas’ Uneven Double Star Project?

Sissy launched this project a few years ago with the objective of determining by observations only, the minimum apertures that will resolve specific combinations of separation and magnitude differences for double stars. It is an observation based project to find the answers, not a theoretical/formula based approach. Sissy wrote an update to this project in the Australian Sky & Telescope in Jan ’16 in which she provided the table of target test pairs and progress to date. Many of these doubles are in our southern skies and from the article and results to date you can see that Sissy is seeking more observations from the Southern Hemisphere.

I have been contributing observation for the test pairs over the last two years. I have found it a rewarding project as it fully extends one’s observing skills given one is seeking to observe at the resolution limits of the scope being used.

I have been able to contribute positive observation reports for 11 of the test pairs to date using my Vixen ED103S. It has been slow progress waiting for the test pair to be in a favourable position and for weather and seeing conditions to cooperate. The most challenging observations to date have been psi Ori (3.0” separation and magnitude delta 4.0), h3874 Pic (2.5” separation and magnitude delta 3.5), kappa Lep (2.0” separation and magnitude delta 2.5) and Dun39 Car (1.5” separation and magnitude delta 1.0).

There are four test pairs remaining on the list that are potentially resolvable by the ED103. They are: 3 Mon (2.0” separation and magnitude delta 3.0), Struve 1171 Cnc (separation 2” and magnitude delta 3.5), theta Gru (1.5” separation and magnitude delta 2.0) and Struve 2303 Ser (separation 1.5” and magnitude delta 2.5). I am just waiting for the test pairs to be as close as possible to culmination and the right seeing conditions to see if I can bag these.

Four of the test pairs in the 1” separation category are targets for southern observers and I am seeking to split these test pairs using my NA140SS. These test pairs, in increasing order of difficulty, are Hrg 47 Car (delta mag 1.5), 41 Oph (delta mag 2.5), 42 Ori (delta mag 3.0) and 8 CMa (delta mag 3.5). Again, am just waiting for the right conditions.

Anyhow, just interested to know if any other double star enthusiasts are targeting these test pairs and reporting their results to Sissy Haas.

Cheers

Steve.