- Double Stars (Cyg) -

And (32) Cep (13) CVn (11) Her (15) Mon (1) Sex (2)
Aql (9) Cet (1) Cyg (25) Hya (4) Oph (1) Tau (11)
Ari (8) CMa (1) Del (4) Leo (21) Ori (8) Tri (4)
Aur (27) Cnc (10) Dra (11) Lib (1) Peg (16) UMa (36)
Boo (19) Com (8) Equ (5) LMi (6) Per (18) UMi (1)
Cam (10) CrB (4) Eri (1) Lyn (18) Psc (7) Vir (6)
Cas (17) Crv (1) Gem (19) Lyr (11) Ser (3) Vul (3)

beta Cyg (**)
Name: beta Cyg, 6 Cyg, Albireo, STFA43
Type: **
Constellation: Cyg
Coordinates: 19h30m43.29s / +27°57'34.90"

Components:
m1 m2 ρ θ Year
AB 3m2 4m7 34.6" 54° 2019
Robert Zebahl
B 16x70, Bortle 7, SQM-L 18.6
2020-07-06: Bright orange & white-bluish.
B 8x40, Bortle 5, NELM 5m5
Well split, but I didn't recognised any color.
80mm f/6.25, 25x
One of the most beautiful double stars in the northern hemisphere. Differences in brightness and color (orange-blue) are brilliant! Even under urban conditions with small aperture an enjoyment!

BLL 49 (**)
Name: BLL49, U Cyg
Type: **
Constellation: Cyg
Coordinates: 20h19m41.66s / +47°54'19.90"

Components:
m1 m2 ρ θ Year
8m0 9m0 65.4" 231° 2015
Robert Zebahl
B 16x70
2020-07-03: Easy split with very good color contrast: white and clear orange.
102mm f/11, 28x, Bortle 6+, SQM-L 19.4
2019-08-22: While the primary component appears quite unspectacular in a white, the companion U Cygni is much more interesting. It is a carbon star whose brightness varies between 5m9 and 12m1 with a period of about 463 days. It appears in mostly intensely orange, and even deep red in the towards its minimum. Extremely rewarding!

../sketches/2019-08-22_u_cyg.jpg

BU 67 (**)
Name: BU67
Type: **
Constellation: Cyg
Coordinates: 20h50m36.05s / +30°54'45.70"

Components:
m1 m2 ρ θ Year
6m8 9m9 1.5" 310° 2015
Robert Zebahl
152mm f/5.9, 270x, Bortle 6
Not split.

BU 167 (**)
Name: BU167
Type: **
Constellation: Cyg
Coordinates: 21h36m13.98s / +30°03'19.50"

Components:
m1 m2 ρ θ Year
6m4 9m9 1.7" 89° 2016
Robert Zebahl
152mm f/5.9, 360x, Bortle 6-
The much fainter component was only occasionally visible as a clear brightening of the first diffraction ring. The diffraction ring itself was only indicated and not visible all around. Difficult.

LSL 1 (**)
Name: LSL1, Lassell 1
Type: **
Constellation: Cyg
Coordinates: 21h34m45.16s / +32°04'42.60"

Components:
m1 m2 ρ θ Year
AB 10m6 11m7 82.1" 82° 2015
AC 10m6 12m1 106.1" 127° 2015
AD 10m6 11m9 21.2" 134° 2015
AE 10m6 13m5 10.5" 331° 2015
BF 11m7 12m1 18.4" 210° 2015
CG 12m1 14m4 11.5" 199° 2015
Robert Zebahl
152mm f/5.9, 180x
Comparatively wide pairs with rather faint components. Observation at nearly full moon. Components A & D easy, B relatively well and C & F quite faint. Components E & G not visible. Overall unspectacular under these conditions.

mu Cyg (**)
Name: mu Cyg, 78 Cyg, STF2822
Type: **
Constellation: Cyg
Coordinates: 21h44m08.57s / +28°44'33.40"

Components:
m1 m2 ρ θ Year
AB 4m8 6m2 1.6" 321° 2018
AD 4m8 6m9 196.9" 44° 2014

../images/binary-star-orbits/STF2822-AB-orbit.jpg

Robert Zebahl
70mm f/5.7, 128x
AB: At 128x I was able to see this double at least elongated.
8" f/6, 171x, Bortle 5, NELM 5m7, SQM-L 20.6
AB: Quite well split with noticeable fainter component.

STF 2486 (**)
Name: STF2486
Type: **
Constellation: Cyg
Coordinates: 19h12m05.03s / +49°51'20.70"

Components:
m1 m2 ρ θ Year
AB 6m5 6m7 7.1" 204° 2019

../images/binary-star-orbits/STF2486-AB-orbit.jpg

Robert Zebahl
B 16x70
2020-07-03: Fine split, but very tight with equally bright components.
70mm f/5.7, 22x, Bortle 6-
At 22x barely split with a slight difference in brightness. At 44x the primary looked orange. I could not determine the color of the companion.

STF 2496 (**)
Name: STF2496
Type: **
Constellation: Cyg
Coordinates: 19h15m19.18s / +50°04'16.00"

Components:
m1 m2 ρ θ Year
AB 6m5 10m0 2.1" 81° 2015
AC 6m5 11m2 186.1" 242° 2003
Robert Zebahl
152mm f/5.9, 270x, Bortle 6
AB: In steadier moments, the much fainter companion can be seen near the first diffraction ring of the primary component.

STF 2578 (**)
Name: STF2578
Type: **
Constellation: Cyg
Coordinates: 19h45m39.65s / +36°05'27.60"

Components:
m1 m2 ρ θ Year
AB 6m4 7m0 14.9" 125° 2018
Robert Zebahl
70mm f/5.7, 22x
At 22x easy with visible brightness and color difference. The slight color difference is even better visible at 44x: A appears white-yellowish, B slightly bluish.

STF 2579 (**)
Name: STF2579, delta Cyg, 18 Cyg
Type: **
Constellation: Cyg
Coordinates: 19h44m58.44s / +45°07'50.50"

Components:
m1 m2 ρ θ Year
AB 2m9 6m3 2.8" 218° 2016

../images/binary-star-orbits/STF2579-AB-orbit.jpg

Robert Zebahl
70mm f/5.7, 200x, Bortle 6-
At 100x only indicated. At 200x the much fainter companion is visible as a slightly elongated brightening on the first diffraction ring.

STF 2605 (**)
Name: STF2605, psi Cyg, 24 Cyg
Type: **
Constellation: Cyg
Coordinates: 19h55m37.82s / +52°26'20.50"

Components:
m1 m2 ρ θ Year
AB 5m0 7m5 2.8" 177° 2014
Robert Zebahl
70mm f/5.7, 100x, Bortle 6-
At 80x difficult. At 100x and 133x the fainter component was clearly visible as small, roundish, partly slightly oval brightening.

STF 2666 (**)
Name: STF2666
Type: **
Constellation: Cyg
Coordinates: 20h18m06.99s / +40°43'55.60"

Components:
m1 m2 ρ θ Year
AB 6m0 8m2 2.8" 245° 2018
AC 6m0 10m7 34.0" 207° 2006
CD 10m7 11m0 24.1" 143° 2018
Robert Zebahl
152mm f/5.9, 129x, Bortle 6, SQM-L 19.6
AB: 2020-06-24: Very nicely separated with clear difference in brightness. The A component appears white-yellowish. The companion was well visible as a tiny star without color.

STF 2671 (**)
Name: STF2671
Type: **
Constellation: Cyg
Coordinates: 20h18m24.76s / +55°23'49.80"

Components:
m1 m2 ρ θ Year
AB 6m0 7m5 3.8" 337° 2016
Robert Zebahl
70mm f/5.7, 57x, Bortle 6-
Pretty tight with a clear difference in brightness. I couldn't see anything conspicuous regarding colors.

STF 2687 (**)
Name: STF2687
Type: **
Constellation: Cyg
Coordinates: 20h26m23.47s / +56°38'19.30"

Components:
m1 m2 ρ θ Year
6m4 8m3 26.2" 118° 2018
Robert Zebahl
B 16x70, Bortle 6, SQM-L 19.2
2020-08-19: Gorgeous sight, separated with distinct brightness difference. Primary component appeared rather white with a greyish companion. With two similarly bright stars to the east and southeast STF 2687 forms a prominent triangle surrounded by several star chains. About 12 arcminutes apart to the southeast of STF 2687 is another pair of stars, which is particularly striking because of its color (bluish & orange).

STF 2691 (**)
Name: STF2691
Type: **
Constellation: Cyg
Coordinates: 20h29m43.18s / +38°07'31.50"

Components:
m1 m2 ρ θ Year
8m1 8m4 17.0" 31° 2017
Robert Zebahl
B 16x70, Bortle 6, SQM-L 19.2
2020-08-19: Nicely separated and in one field of view together with 40 Cygni and Messier 29. Moderate distance and brightness difference, relatively conspicuous even though the environment is rather rich in stars.
70mm f/5.7, 22x
2020-07-29: At 22x clearly separated with little difference in brightness. Colorwise the components appeared different: yellowish-orange & bluish. The color impression was a bit more intensive at 44x: slightly orange & bluish.

STF 2758 (**)
Name: STF2758, 61 Cyg
Type: **
Constellation: Cyg
Coordinates: 21h06m53.95s / +38°44'57.90"

Components:
m1 m2 ρ θ Year
AB 5m2 6m0 31.6" 154° 2018

../images/binary-star-orbits/STF2758-AB-orbit.jpg

Robert Zebahl
152mm f/5.9, 22x, Bortle 6, SQM-L 19.6
2020-06-24: Beautifully separated, bright, striking, especially the colors: bright orange and orange.

STF 2789 (**)
Name: STF2789
Type: **
Constellation: Cyg
Coordinates: 21h19m58.84s / +52°58'44.10"

Components:
m1 m2 ρ θ Year
AB 7m7 7m9 6.8" 115° 2018
Robert Zebahl
70mm f/5.7, 44x, Bortle 6-
At 22x almost separated. The double star appeared strikingly orange and forms a conspicuous, nearly isosceles triangle with neighbouring stars. At 44x clearly separated, relatively close together with a small difference in brightness.

../sketches/2019-07-28_stf2789.jpg

STF 2832 (**)
Name: STF2832
Type: **
Constellation: Cyg
Coordinates: 21h49m14.48s / +50°30'54.20"

Components:
m1 m2 ρ θ Year
AB 7m8 8m3 13.0" 213° 2018
AC 7m8 11m0 45.8" 321° 2018
BC 8m3 11m0 51.5" 335° 2018
Robert Zebahl
B 16x70, Bortle 6, SQM-L 19.2
AB: 2020-08-19: Very nicely separated, slight difference in brightness. No color was visible. Towards northwest is pi 1 Cygni, which is surrounded by several medium bright and fainter stars and together with STF 2832 presents a very attractive view. The region southeast of STF 2832 looks rather poor.

STFA 50 (**)
Name: STFA50, omicron Cyg, 30/31 Cyg
Type: **
Constellation: Cyg
Coordinates: 20h13m37.90s / +46°44'28.80"

Components:
m1 m2 ρ θ Year
AD 3m9 4m8 336.7" 322° 2016
AC 3m9 7m0 108.6" 173° 2016
Robert Zebahl
naked eye, Bortle 6+, SQM-L 19.4
AD: Well split with noticeable difference in brightness.
B 8x40, Bortle 6-, NELM 5m0
AD: Wonderful double star for binoculars. Large distance of the components, brighter once (31 Cyg) appeared slightly orange, the fainter (Cyg 30) more bluish.
B 8x40, Bortle 7, NELM 5m0, SQM-L 18.6
AC: Observation at full moon. Easily split with big difference in brightness. Brighter component slightly orange. C component rather faint.
B 16x70
2020-07-03: Fantastic sight. A: bright orange, D: white-bluish, C: light blue. Very beautiful field.
80mm f/6.25, 25x, Bortle 7, NELM 5m0, SQM-L 18.6
AC: Similar to the observation with binoculars. C component appeared bluish and gave good contrast to the orange colored 31 Cyg.
102mm f/11, 28x, Bortle 6+, SQM-L 19.4
Bright, wide apart and wonderful contrast in color. A: light yellowish-orange, C: blue, D: light blue.

../sketches/2019-08-22_omicron_cyg.jpg

STT 386 (**)
Name: STT386
Type: **
Constellation: Cyg
Coordinates: 19h48m16.51s / +37°09'37.50"

Components:
m1 m2 ρ θ Year
8m5 8m6 1.0" 71° 2018
Robert Zebahl
152mm f/5.9, 270x, Bortle 6-
Clearly visible as a double star with touching diffraction disks. Not difficult.

STT 403 & STF2657 (**)
Name: STT403 & STF2657, WDS20144+4206
Type: **
Constellation: Cyg
Coordinates: 20h14m21.53s / +42°06'15.60"

Components:
m1 m2 ρ θ Year
STT403 AB 7m3 7m6 1.0" 171° 2016
STF2657 AC 7m3 9m8 11.6" 32° 2015
Robert Zebahl
152mm f/5.9, 270x, Bortle 6
STT403 (AB): At 129x clearly elongated, notched. At 270x clearly split, but very tight with almost touching diffraction disks. Visible, but very small difference in brightness. Inconspicuous color.

STT 410 (**)
Name: STT410
Type: **
Constellation: Cyg
Coordinates: 20h39m33.31s / +40°34'46.80"

Components:
m1 m2 ρ θ Year
AB 6m7 6m8 0.9" 3° 2018
AB-C 6m8 8m7 68.6" 70° 2018
AB-D 6m8 10m0 106.6" 327° 2018

../images/binary-star-orbits/STT410-AB-orbit.jpg

Robert Zebahl
152mm f/5.9, 270x, Bortle 6-
All four components easily visible. The pair AB shows two clear, equally bright, overlapping diffraction disks.

../sketches/2019-09-06_stt410.jpg

STT 413 (**)
Name: STT413, 54 Cyg, lambda Cyg
Type: **
Constellation: Cyg
Coordinates: 20h47m24.53s / +36°29'26.70"

Components:
m1 m2 ρ θ Year
AB 4m7 6m3 0.9" 3° 2018

../images/binary-star-orbits/STT413-AB-orbit.jpg

Robert Zebahl
102mm f/11, 280x, Bortle 6, SQM-L 19.4
The diffraction disk of the primary component was slightly elongated towards north. The air here was however a bit too unsteady for an accurate observation.
152mm f/5.9, 300x, Bortle 6, SQM-L 19.3
Observation with an achromat. The fainter component was visible as a permanent brightening of the first diffraction ring.
152mm f/8, 300x, Bortle 6-
2020-08-24: Observation with an ED refractor. At 171x partially, at 200x clearly visible as '8'. At 300x two clear, overlapping diffraction disks of differently bright components.

STT 426 (**)
Name: STT426, 60 Cyg
Type: **
Constellation: Cyg
Coordinates: 21h01m10.93s / +46°09'20.80"

Components:
m1 m2 ρ θ Year
5m4 9m5 2.9" 159° 2017
Robert Zebahl
152mm f/5.9, 129x, Bortle 6
Much fainter companion outside of first diffraction ring. Better visible at 270x.

STT 437 (**)
Name: STT437
Type: **
Constellation: Cyg
Coordinates: 21h20m50.12s / +32°27'10.20"

Components:
m1 m2 ρ θ Year
AB 7m2 7m4 2.4" 19° 2018

../images/binary-star-orbits/STT437-AB-orbit.jpg

Robert Zebahl
70mm f/5.7, 57x, Bortle 6-
At 57x separated, but close together. Near, slightly brighter star in nice contrast. The double star shows a distinct orange coloration. At 100x small difference in brightness visible.