[ngcles]

Hi Pete,

Good guesses on some but not quite right. All are catalogues of pairs that (generally) are named after the astronomer who made the discovery.

A capital Sigma (Σ) indicates it is a Struve pair -- ie Fredrick von Struve (often seen as STF).

The Capital S is for James South a collaborator with John Herschel who also discovered a great many pairs himself.

h: I've seen a lot of these in the past but now I'm going on memory as to their origin. I think these are John Herschel's pairs as opposed to capital (H) which were his dads. These h are often refered to (again I think) as HJ to avoid confusion between H and h (again that's from memory). Someone with a greater knowledge of catalogues might like to correct me here if I'm wrong ...

A few other common ones (a far from exhaustive list):

A is for Aitken

BU is for Sherburne Burnham (many of these are very close and/or difficult pairs). Not to be confused with Robert Burnham the astro-author.

DUN is for James Dunlop.

HRG Lawrence Hargrave.

I is for Robert Innes (who discovered Proxima Centauri).

ΟΣ is for Otto Struve (Often STT) and his second catalogue ΟΣΣ.

R is for Henry Russell (Sydney Observatory).

RMK is for Carl Rumker.

RST is R.A Rossiter.

and of course WDS is for Washington Double Sars -- the most exhaustive list of all that includes nearly all pairs found in other catalogues.

Beware with the catalogues of pairs when you find them on the net and elsewhere -- they may not be in J2000 coordinates. Some are in earlier epochs and you may have to precess the positions to the current epoch.

That's a starting point at least ...


Best,

Les D