- Double Stars (Cyg) -

And (43)	Cet (1)	Del (4)	Lib (1)	Per (27)	UMi (1)
Aql (9)	CMa (2)	Dra (11)	LMi (6)	Psc (10)	Vir (9)
Ari (8)	Cnc (10)	Equ (5)	Lyn (18)	Pup (1)	Vul (3)
Aur (28)	Com (8)	Eri (1)	Lyr (11)	Ser (3)
Boo (20)	CrB (4)	Gem (22)	Mon (1)	Sex (2)
Cam (11)	Crv (1)	Her (16)	Oph (1)	Tau (11)
Cas (17)	CVn (11)	Hya (4)	Ori (9)	Tri (4)
Cep (13)	Cyg (26)	Leo (24)	Peg (16)	UMa (37)

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!

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.

ENG 72 (**)

Name:	ENG72, 29 Cyg
Type:	**
Constellation:	Cyg
Coordinates:	20h14m31.98s / +36°48'22.10"

Components:
		m₁	m₂	ρ	θ	Year
	AB	5m0	6m7	215.3"	155°	2016

Robert Zebahl
B 16x70, Bortle 7 2020-09-20: Widely separated pair in nice star field with moderate difference in brightness and beautiful color contrast: whitish & yellow-orange.

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



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



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



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



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.

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.

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 & STF 2657 (**)

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



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.

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



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



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.