Tuesday, March 19, 2019

received STF 1143 data (Halifax)

I wanted to image a double star in need of attention using a different method, a new technique, now that the WDS "neglected" system as been decommissioned.

After filtering for "old" data, I came across the entry 07481+0525 STF1143 with the last entry reported in 1825! Almost 200 year old data.

neglected double-star STF 1143 in luminance

Luminance only, ½ second subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

Struve 1143 is also known as HD 63241 or SAO 115947. Stars visible to magnitude 14 and beyond are visible.

I found some notes in the WDS database: Some error in position. See note in BDS II. Bu_1906; This may be STF1134AB with a larger error than is typical for a FGW Struve measure.

Now Σ1143 is supposed to be a somewhat tight pair of unequal stars. The primary is mag 6.6 with a secondary at mag 11. The separation is purportedly 9.3 seconds of arc. B is supposed to the to the south-east.

I don't see anything...

The equal pair of stars to the north (not noted as a double) are separated by about 22". So 1143 A and B should be visible at half that distance.

Nothing.

Curious.

What did Friedrich Georg Wilhelm see?

Regardless, it is a lovely little pattern of stars...

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Another curious thing about this is that SkyTools shows a star north-east of the upper pair, of equal brightness. It says it is NSV 3739. I see nothing.

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Strange. When I went looking for the completed data the morning after, the target showed as pending... Some short of glitch which in the end worked itself out.

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