surprised by STF 2877 (Halifax)

I spotted clear skies moving in over Nova Scotia for Saturday night. Given the "rare micro blue puny full Hunter's aka Falling Leaves creepy Moon" was out, I thought I'd aim at a double star. Found STF 2877 in Haas's book, a pair in Pegasus, noting the interesting colour descriptors. Also known as SAO 107756.

Luminance filter, 1 second subexposures, 12 stacked shots. FITS Liberator, GIMP. North is up; left is east.

The two brightest stars are A and B, what Sissy refers to as grapefruit-orange and powder-blue. I look forward to assembling this data in colour..

But there are some surprises in this image from the Burke-Gaffney robotic telescope.

There's a faint star on the left/east diffraction spike, close in. Is it another companion? Is this the C star? SkyTools 3 Pro does not list a C element.

ST3P has revealed that the next brightest star to the north-west of A is the D partner.

Compelling is the equally luminous star due west.

And then, perhaps most fun, is the faint, tight, equal, and obvious pair to the north-east. Cool! Two in the view! SkyTools has poor data for this, showing only a single star, GSC 01685-0559 at magnitude 9.7.

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Data from Stella Doppie on Σ 2877:

22143+1711 SYSTEM COMPONENTS

First discovered in 1825. The prime star is magnitude 6.65.

COMP, PA, SEP, MAG2
AB, 25, 24.0, 9.23
AC, 44, 97.3, 12.42
AD, 309, 101.2, 11.31

A quadruple system with 4 visible stars in this system.

This means the C compatriot is to the north-east and well away, about the same distance as D. Yep, OK, spotted easily in the image. Beyond B, roughly on the same line. Dimmer than D.

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Searched the WDS. Found the faint pair: 22146+1714 HDO 170. First discovered in 1867. PA is 241 and the last separation was 7.3. Mag 11.4 and 11.6 stars. Precise location is 221438.65+171333.5. Angle, separation, and brightness values all look good.

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As usual, the more I look...

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OK. Here's the full colour version.

FITS Liberator, Photoshop.

The A star of STF 2877 is definitely intense orange. B is pale blue. So there ya go.

D looks a bit red!

C is a darker blue than B.

HDO 170 A and B are nearly equal. A is maybe white or white with a hint of blue. B seems a tiny bit warmer. Tricky.