Object: Struve 331

Constellation
RA / DEC
Magnitude A / B
Separation
Position angle
Spectral class
Colour A / B
: Perseus
: 03:00:54 / +52.21
: 5.2 / 6.2
: 11.9"
: 85°
: B7V / B9V
: white with a hint of yellow / white
Details sketch
Date / Time
Observing Location
Seeing / Transparency
Telescope
Eye-piece
Magnification / Field of View '
: 07/12/08 / 20:12
: Landgraaf
: 3 / 3
: Orion Optics UK 300 mm
: 17 mm Nagler type 4
: 94 / 52
Stacks Image 1010
Observing report
Struve 331 is a very easy double. Even in the 35mm Panoptic both components are split. I personally found it a bit boring object, and I don't know why Sissy Haas marks this double as a "showpiece". The optimum magnification for Struve 331 is the 17mm Nagler. The brighter A-component shines in brilliant white with a hint of yellow, and the dimmer B-component is definitely white. The double is very well split, a more or less wide double in the big dob. To the north of Struve 331 I detect a triangle of faint stars. The whole setting and surroundings of Struve 331 are more or less as boring as the double itself.
Notes
Struve 331 is an optical double, consisting of two main sequence dwarfs. Haas sees the colors as lemon-white and dusty blue-green. Webb reports seeing them as white-bluish.