Ambience: Once again, the hedgehogs are out in force, enjoying a warm, dry evening. I have to be careful where I step on the lawn, as a mistake would be very uncomfortable for both of us. One or two bats fluttering about in the gloaming.

Comments: This star is also known as Kappa Her. According to R. H. Allen, its proper name, which has many spellings, is Marfik. I found it without difficulty by starhopping from nearby Beta Her. It forms the southernmost star in a small but attractive, slightly curved asterism. Kappa is a beautiful bright pair, so fine that I found it hard to believe it had not been in this group's original Hercules project. However, Luis is right - we have not previously studied it. It might appear rather wide and uninteresting in a larger telescope, but in the Agnes Clerke refractor, with its 2° field of view, it is easy but pleasingly close.

There is a subtle difference in hue between the two components. To my eye, both appear yellow but the primary is paler than its companion, which occasionally displays a slight orange tinge. After completing my observation, I consulted my small astronomical library to see what others had said about its colours. Webb describes it as light yellow and pale tawny, or 'garnet', and quotes Franks's description: "pale yellow, dull orange". The gallant Admiral Smyth saw it as light yellow and pale garnet, exactly the same description as that given by R. H. Allen.

NAME SEP PA NOTES

With x35 it was very clearly resolved and I found it a very pretty bright pair. The magnitude difference I estimated to about 1 mag. x115 was even better and the PA estimated to about 20deg. My impression of colors was that the brighter star is a bit yellowish and the companion is whiter. Using the 7x50 finder I could discern the double with some determination but it was very close and both stars were touching.

My friend Peter Wienerroither has a project underway of imaging many wide double stars visible in binoculars or a very small telescope – see:

http://homepage.univie.ac.at/peter.wienerroither/pwafodse.htm

He does tricolor images with a 106mm refractor at a focal length of 1100mm using a CCD camera SXV-H9 and RGB filters. His composite image of Kappa Her is at

http://homepage.univie.ac.at/peter.wienerroither/pwafods/16081+1703.htm

I used 10 of his CCD frames and measured them using Astrometrica software by Herbert Raab and the UCAC2 catalog to establish the precise focal length and field orientation. Then I used AIP4WIN software to measure the distance and PA.

My results for STF2010 AB are:
distance 27.3 arcsec ± 0.1 arcsec
PA 13.1 deg ± 0.1 deg.

On 4 of the G(reen) and R(ed) frames with 10 seconds exposure the faint C companion was measurable: STF2010 AC:
distance 63.0 arcsec ± 0.6 arcsec  PA 212.3 deg ± 0.6 deg

The measurement errors tend to be larger for very faint stars with low signal to noise ratio. The star seems to be yellow or
even red because it did not show up in the B(lue) images.

Very nice pair. Observed in the 12mm Ploessel. Estimated PA is 10°. "A's" color is blue. "B's" color is green

Primary Colour: Cream /Yellow Secondary Colour: Orange General Notes: Well matched pair, very easy split Measurements: PA: 11 Sep: 25" (3x Barlow & 12.5mm MG. scale constant 5" per division)