Wednesday, May 17, 2017

looked into BU 284

Dove into the Washington Double Star database.

Initially I didn't see β284 but when I checked the coordinates again and saw the RA was 18:15, I realised I was in the wrong table. Then when I found BU 284, I noted G and H companions! Ah ha. Letters beyond ST3P... I checked the locations using my Excel radar chart.

I made many discoveries.

1. The BR pair details are noted as 324 degrees and 5 arcminutes in the SkyTools 3 Pro Object Information box but the chart view has it plotted 12" away! I added a SkyMark for where it should be in the chart. Happily, this position closely matches the image from last night. WDS says 326 and 5.2. And when I calculated the AR deets, the Excel chart showed good correspendence.

2. When I took in the G and H references in the WDS I thought that this might be more stars, perhaps accounting for some of the other somewhat bright neighbours around D and P, in the busy field. But this does not appear to be the case (as will become obvious below).

3. The G star in Washington Double Star is what SkyTools calls P. Ah, OK.

4. Finally, the H star is WDS is what ST3 calls Q. Right.

So it seems the WDS does not have P and Q references; rather it uses G and H. But still both use S.

Made me wonder if there are other identified WDS pairs in the same spot. Made a note to look.

§

No other entries except ARA 743CQ which I calculated to be at a 71° angle from A with a separation of 21.4".

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