What is the best source of information on Separation & PA ?

[peterbolson]

Being fairly new to studying double stars I get confused by the different figures given in , for example, the Cambridge DSA, Astronomical League list, SkySarari plus app on ipad, Burnhams Celestial Handbook, etc, to name but a few. I realise that the figures will vary over time but which are the most authoritative up to date ones ?

Information about distance away & spectral class also seems to vary.

Thanks

Peter

Incidentally I had wonderful views of the triple Mu Bootis last night. One of my favourites so far !

[Mark at Beaufort]

Peter I understand that the principle database for double stars is the 'Washington Double Star Catalogue' which is updated nightly. The database is maintained by the United States Naval Observatory.

I agree with you comparing different publication you do get different information. So if you really want the most accurate details I would look on line for the WDS.

Mark

[peterbolson]

Hi Mark

I thought that might be the answer but I find the WDS website very difficult to find my way around. Where abouts is the information ? Is it in the catalogue ( which I don't understand ! ) ?

Peter

[melsmore]

I recommend you use http://stelledoppie.goaction.it/index2.php?section=1 . It is an Italian website that provides a very nice front end to the WDS, ORBIT6, HIPPARCOS.and others.

[peterbolson]

Hi Melsmore

That's a wonderful website. Thanks so much.

Peter

[carlc]

Melsmore

That's great - I downloaded LADIC but haven't got it to work yet. http://www.carbonar.es/s33/Fuzzy-splitting/fuzzy-splitting.html

Though the information on the Spirit of 33 lists can be quite useful as there are magnification and scope parameters given. http://www.carbonar.es/s33/33.html

[schotten1944]

Try the Saguaro Astro Club Database of Double Stars. Much easier to navigate than WDS and pretty well accurate.

http://www.saguaroastro.org/content/downloads.htm

Phil

[inZet]

stelledoppie.goaction.it is my site. I created it to easly get double star information. Data are based on WDS, the official catalog for this kind of objects. It's the only updated database available. Don't trust other data: a double star may change separation and angle over time!

That said, the WDS is not perfect. Errors may happen. For example I reported wrong magnitudes for circa 1% of the entire database to be corrected. Magnitude of a star depends on the band you are measuring: flux is different at different wavelenghts, and filters may create confusion even if there's a standard method to measure this information.

For distances, most of data came from the Hipparcos satellite source. At the first run, it failed to recognize close doubles: sometimes it measured the primary, sometimes the secondary, sometimes a mean of the two. Data was corrected later, but some catalogs are still affected by errors.

Enthopy rules.

Gianluca

[todd8137]

They all different and they a removing all the time so there's not that's right just estimation I view these all the time

pat