- Double Stars (UMa) -

And (55)	Cep (25)	Cyg (93)	Leo (35)	Peg (34)	SGE (1)
Aql (52)	Cet (5)	Del (16)	Lep (6)	Per (35)	Sgr (10)
Aqr (4)	CMa (5)	Dra (19)	Lib (1)	Psc (17)	Tau (15)
Ari (8)	CMi (3)	Equ (7)	LMi (6)	Pup (1)	Tri (5)
Aur (28)	Cnc (10)	Eri (3)	Lyn (18)	Sco (4)	UMa (46)
Boo (32)	Com (13)	Gem (30)	Lyr (32)	Sct (4)	UMi (5)
Cam (17)	CrB (10)	Her (58)	Mon (12)	Ser (21)	Vir (20)
Cap (6)	Crv (4)	Hya (11)	Oph (14)	Sex (6)	Vul (12)
Cas (39)	CVn (16)	Lac (13)	Ori (38)	Sge (8)

41 Lyn (**)

Name:	41 Lyn, S598
Type:	**
Constellation:	UMa
Coordinates:	09h28m39.99s / +45°36'06.50"

Components:
		m₁	m₂	ρ	θ	Year
	AB	5m5	7m8	69.7"	160°	2017


This star has the designation 41 Lyn but is assigned to UMa. At the time, when Flamsteed numbered the stars, the constellation boundaries were not exactly defined. Another example is 10 UMa, which is located in Lyn today.
Robert Zebahl
B 8x40, Bortle 7, NELM 5m0, SQM-L 19.2 Fairly well split with fainter component.

67 UMa (**)

Name:	67 UMa
Type:	**
Constellation:	UMa
Coordinates:	12h02m06.80s / +43°02'44.30"

Components:
		m₁	m₂	ρ	θ	Year
FOR1	AB	5m2	6m7	274.4"	62°	2015
ARN5	AC	5m2	8m5	375.9"	25°	2015
FOR1	AD	5m2	8m9	363.2"	268°	2015

Robert Zebahl
B 8x40 2020-04-05: The pair AB stands out immediately and shows itself in beautiful colors: A white-yellowish, B slightly orange. Almost at right angles to pair AB component C is visible as a faint star at a slightly smaller distance. I did not pay attention to the even fainter component D.
55mm f/9.1, 27x 2020-04-05: Components A, B and C easily visible with decreasing brightness. I did not consider component D. A: white-yellowish, B: pale orange. I liked the view in the 8x40 binoculars better.

BU 408 (**)

Name:	BU408
Type:	**
Constellation:	UMa
Coordinates:	08h59m00.62s / +63°25'42.80"

Components:
	m₁	m₂	ρ	θ	Year
	7m3	9m6	2.8"	345°	2018

René Merting
100mm f/6.4, 142x bei 107x ist nordöstlich von A ein Helligkeitspeak erkennbar, aber nicht richtig greifbar - bei 142x dann zeigt sich in ruhigen Momenten die schwächere Komponente knapp abgesetzt von A - großer Helligkeitsunterschied, mindestens 2.5 Größenklassen

BU 1077 (**)

Name:	BU1077, alpha UMa, 50 UMa, Dubhe
Type:	**
Constellation:	UMa
Coordinates:	11h03m43.84s / +61°45'04.00"

Components:
		m₁	m₂	ρ	θ	Year
	AB	2m0	5m0	0.8"	342°	2017
	AC	2m0	7m2	370.0"	205°	2015



Robert Zebahl
70mm f/5.7, 22x AC: 2020-04-07: Very wide, uneven & inconspicuous pair. A appeared white-yellowish, for B I could not detect any color.

iota UMa (**)

Name:	iota UMa, 9 UMa, Talitha
Type:	**
Constellation:	UMa
Coordinates:	08h59m12.45s / +48°02'30.60"

Components:
		m₁	m₂	ρ	θ	Year
HJ2477	A-BC	3m1	9m2	2.4"	90°	2017
HU628	BC	9m9	10m1	0.9"	206°	2017



Robert Zebahl
152mm f/5.9, 300x, Bortle 6, SQM-L 19.4, Seeing 3/5 A-BC: 2020-04-24: The seeing (3/5) was not good enough for a split.

Messier 40 (**)

Name:	Messier 40, M40, Winnecke 4, WNC4
Type:	**
Constellation:	UMa
Coordinates:	12h22m12.53s / +58°04'58.60"

Components:
	m₁	m₂	ρ	θ	Year
	9m7	10m1	50.0"	83.0°	-


Winnecke 4 is an optical double star with an angular distance of 50 arc seconds. Charles Messier had probably mistaken this double star as a nebula and therefore included it in his catalog. It is the only double star in Messier's catalog.
Robert Zebahl
B 16x70, Bortle 6-, SQM-L 19.2 2021-09-02: Easy to separate, but quite faint and inconspicuous. A small difference in brightness is visible.
René Merting
B 8x20 knapp direkt sichtbar, indirekt wie ein schwacher Stern - leicht diffuser Eindruck
B 8x30 beide Sterne sind sehr schwach als längliche Aufhellung zu erkennen, mehr nicht
B 10x50 zwei relativ einfach zu sehende schwache Sterne, ordentlich getrennt - beide Sterne sind gleich hell
B 16x70 Zenitbeobachtung (leider kein echter Vorteil im Fujinon) - direkt als kompakter nebliger Fleck erkennbar, indirekt offenbaren sich zwei Sterne
B 18x70 Zenitbeobachtung (definitiv ein Vorteil, weil besseres Einblickverhalten als beim Fujinon 16x70) - zwei relativ einfach zu sehende schwache Sterne, ordentlich getrennt - beide Sterne sind gleich hell
100mm f/6.4, 20x bei 32x sind beide Komponenten gut getrennt erkennbar - beide Sterne sind schwach und ohne großen Helligkeitsunterschied, der Stern im Osten wirkt leicht schwächer - zurück auf 20x sind beide Sterne noch immer bequem getrennt voneinander zu bestaunen
8" f/4, 40x bei 40x sind eindeutig zwei gleichhelle nah beieinander liegende Sterne auszumachen
12.5" f/4.5, 45x ein Sternpaar, das komfortabel getrennt ist - beide Sterne wirken grauorange

STF 1193 (**)

Name:	STF1193
Type:	**
Constellation:	UMa
Coordinates:	08h20m40.32s / +72°24'26.00"

Components:
		m₁	m₂	ρ	θ	Year
	AB	6m2	9m7	42.4"	90°	2015
	BC	9m8	12m7	58.8"	6°	2015

Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.3 AB: 2020-04-21: Beautifully separated with much fainter companion. The primary component shines in a bright, refreshing yellow. Rewarding!
René Merting
12.5" f/4.5, 45x AB: bei 45x … oh wow, was für eine Farbe bei Komponente A - so ein intensives Gelb habe ich noch nirgends gesehen, gleißendes Rapsgelb - die deutlich schwächere Komponente B im Osten in weitem Abstand ist bei der Farbe von A eher uninteressant, B ist ohnehin nur grau schimmernd

STF 1258 (**)

Name:	STF1258
Type:	**
Constellation:	UMa
Coordinates:	08h43m25.41s / +48°51'41.90"

Components:
	m₁	m₂	ρ	θ	Year
	7m7	7m9	10.1"	331°	2019

Robert Zebahl
B 16x70, Bortle 7, SQM-L 18.6 2020-07-05: Immediately visible as a double star, separated but pretty close with similar bright components.
70mm f/5.7, 22x, Seeing 3/5 Easy to separate at 22x, similarly bright components at moderate distance. At 57x very small difference in brightness noticeable. The components appeared slightly orange and white-bluish, with the color changing from one component to another. A very strange effect, which I observed several times.

STF 1275 (**)

Name:	STF1275
Type:	**
Constellation:	UMa
Coordinates:	08h51m26.19s / +57°31'38.10"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m7	8m9	1.9"	198°	2019

Robert Zebahl
70mm f/5.7, 100x At 100x and 150x not permanently split. Components very close together.

STF 1280 (**)

Name:	STF1280
Type:	**
Constellation:	UMa
Coordinates:	08h55m24.82s / +70°47'39.20"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m8	9m1	3.4"	357°	2019
	AC	8m8	12m4	398.4"	88°	2015
	BC	9m1	12m4	398.5"	88°	2015



Robert Zebahl
70mm f/5.7, 67x, Bortle 6, SQM-L 19.2 AB: 2021-04-03: Rather faint double star with components still pretty close together and little difference in brightness.
René Merting
100mm f/6.4, 72x AB: ein knapp getrenntes Sternpaar - beide Sterne sind annähernd gleich hell und strahlen rein weiß - bei 144x eine ordentlichere Trennung, Komponente A im Süden strahlt in einem wärmeren Weiß

STF 1306 (**)

Name:	STF1306, sigma 2 UMa, 13 UMa
Type:	**
Constellation:	UMa
Coordinates:	09h10m23.53s / +67°08'03.30"

Components:
		m₁	m₂	ρ	θ	Year
	AB	4m9	8m8	4.3"	348°	2016
	AC	4m9	10m3	197.8"	148°	2003



Robert Zebahl
70mm f/5.7, 100x, Seeing 3/5 AB: Companion almost permanently visible as elongated, non-condensed brightening of the first diffraction ring of the primary component at the correct position angle.

STF 1312 (**)

Name:	STF1312
Type:	**
Constellation:	UMa
Coordinates:	09h10m18.19s / +52°23'05.70"

Components:
	m₁	m₂	ρ	θ	Year
	8m3	8m8	4.7"	147°	2019

Robert Zebahl
70mm f/5.7, 44x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x clearly elongated, at 31x instantly visible as '8', sometimes barely separated. At 44x clearly separated with little difference in brightness. For the perception of colors the double star was too faint. Together with STF 1321 visible in one field of view.

STF 1315 (**)

Name:	STF1315
Type:	**
Constellation:	UMa
Coordinates:	09h12m45.94s / +61°40'32.70"

Components:
	m₁	m₂	ρ	θ	Year
	7m3	7m7	25.1"	28°	2019

Robert Zebahl
70mm f/5.7, 22x, Seeing 3/5 Medium bright double star, easy to separate with attractive distance and slight difference in brightness. Together with 16 UMa in one field of view. The brighter component appeared slightly orange, the fainter one showed a hint of blue. However, the colors of the components changed over time. At 57x similar view.
René Merting
100mm f/6.4, 20x bei 32x gibt es nix zu meckern, ein bequem getrenntes Pärchen - Komponente B im NO ist maximal eine halbe Größenklasse schwächer - leichter Farbkontrast - noch schöner bei 20x, auffällig im Umfeld

STF 1318 (**)

Name:	STF1318
Type:	**
Constellation:	UMa
Coordinates:	09h13m38.79s / +46°59'25.30"

Components:
	m₁	m₂	ρ	θ	Year
	7m8	9m5	2.4"	228°	2018

Robert Zebahl
70mm f/5.7, 133x, Bortle 6, SQM-L 19.4 Separated with clear difference in brightness. The faint companion is slightly outside the first diffraction ring of the primary component.

STF 1321 (**)

Name:	STF1321
Type:	**
Constellation:	UMa
Coordinates:	09h14m22.79s / +52°41'11.80"

Components:
		m₁	m₂	ρ	θ	Year
	AB	7m8	7m9	16.9"	99°	2019
	AC	7m8	14m5	145.7"	64°	2010
	AD	7m8	11m9	136.4"	129°	2015



Robert Zebahl
B 16x70, Bortle 7, SQM-L 18.6 AB: 2020-07-05: Very nice view, striking, easily separable. A slight difference in brightness is visible. At first glance the double star appeared noticeably orange compared to the surrounding stars, on closer look a color difference of the two components was visible: orange & rather white.
70mm f/5.7, 22x, Bortle 6 AB: 2020-04-11: At 22x pretty wide pair with equally bright components. Striking colors: slightly orange & white-bluish, but it was a bit difficult to assign the colors to the components. At 44x slightly better color perception.
70mm f/5.7, 31x, Bortle 6, SQM-L 19.6 AB: 2020-04-19: Together with STF1312 in one field of view. At 22x very nice sight, easy to separate, attractive separation. Immediately apparent. A color difference is visible: dark yellow, orange. Also beautiful to see at 44x. Best view at 31x.

STF 1331 (**)

Name:	STF1331
Type:	**
Constellation:	UMa
Coordinates:	09h20m46.02s / +61°20'58.40"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m5	8m7	0.9"	153°	2017
	AC	8m5	11m6	13.5"	186°	2015
	AD	8m5	14m5	19.4"	117°	2015
	AE	8m5	9m8	139.1"	223°	2015

Robert Zebahl

152mm f/5.9, 180x, Bortle 6, SQM-L 19.4
2020-04-13: The wide pair AE is already visible at 22x with a significant difference in brightness, but quite inconspicuous. A appeared white-yellowish, E rather orange. The close pair AB appeared immediately elongated at 129x, partly visible as '8'. At 180x, AB was just separated with a fine black space between them. The faint C component was only visible with averted vision. Best view at 180x. The even fainter D component was out of range.

STF 1346 (**)

Name:	STF1346
Type:	**
Constellation:	UMa
Coordinates:	09h25m37.88s / +54°00'57.50"

Components:
		m₁	m₂	ρ	θ	Year
	AB	7m7	8m6	5.8"	314°	2017
	BC	8m6	11m8	93.9"	188°	2015

Robert Zebahl
70mm f/5.7, 44x, Bortle 6, SQM-L 19.6 AB: 2020-04-19: At 31x very tight with clear difference in brightness. At 44x very fine separation. Component A appeared creamy white, B partly slightly orange.

STF 1349 (**)

Name:	STF1349
Type:	**
Constellation:	UMa
Coordinates:	09h31m09.89s / +67°32'28.40"

Components:
	m₁	m₂	ρ	θ	Year
	7m5	9m0	19.2"	166°	2015

Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x easy to separate with significant difference in brightness. The primary component appears whitish, the companion darker. At 44x, the primary component looks rather white-yellowish, the companion greyish.
René Merting
100mm f/6.4, 32x bei 32x stehen beide Sterne bequem getrennt auseinander - Komponente B im Süden ist eine knappe Größenklasse schwächer und kupfergrau - ein schönes Doppel-Doppel zusammen mit STF1350 gut 47' weiter südsüdöstlich
12.5" f/4.5, 45x bei 45x steht das Pärchen gut auseinander - Komponente B ist eine dreiviertel Größenklasse schwächer und wirkt grauweiß - A ist weiß mit einem zarten Stich ins Gelbe

STF 1350 (**)

Name:	STF1350
Type:	**
Constellation:	UMa
Coordinates:	09h34m19.56s / +66°47'42.30"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m3	8m3	10.2"	249°	2015
	AC	8m3	9m2	131.0"	216°	2015

Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x A & B equally bright and still pretty close together. Component C is visible at a much greater distance. At 44x, A & B show a color difference: orange, white-bluish.
152mm f/5.9, 100x, Bortle 6-, SQM-L 19.1 At 22x, all three components are already visible, with A & B still standing quite close together. Component C is less prominent. At 69x and 100x, the pair AB shows a nice color contrast: The eastern component mostly appeared in a slightly shiny orange, while the other component appeared more white-bluish. During the observation, however, the colors changed between both components. At the time of observation, the pretty bright comet C/2019 Y4 Atlas was also in the same field of view - a great scene! Note to the sketch: The positions of the stars to each other do not exactly match, also the alignment of the pair AB to C.
René Merting
100mm f/6.4, 32x AB: bei 32x ein schönes enges Paar zweier gleich heller Sterne, knapp getrennt - STF1350 AB bildet mit vier ähnlich hellen Sternen westlich ein Muster, ähnlich einer Sense AC: bei 32x bildet STF1350 AB mit vier ähnlich hellen Sternen westlich ein Muster, ähnlich einer Sense - der erste der vier Sterne bzw. der nächststehende Stern südsüdwestlich mit mehr als zehnfachem Abstand AB ist Komponente C, er ist schätzungsweise eine halbe Größenklasse schwächer
12.5" f/4.5, 45x AB: bei 45x ein schönes enges Paar zweier gleich heller Sterne, beide strahlen weiß

STF 1351 (**)

Name:	STF1351, 23 UMa
Type:	**
Constellation:	UMa
Coordinates:	09h31m31.57s / +63°03'42.50"

Components:
		m₁	m₂	ρ	θ	Year
	AB	3m6	9m2	22.7"	267°	2015
	AC	3m7	11m8	107.4"	232°	2015

Robert Zebahl
70mm f/5.7, 22x AB: 2020-04-07: Well separable with a significant difference in brightness, where the companion appearing only as a tiny star close to the primary component. The primary component itself appeared bright and rather whitish.
René Merting
100mm f/6.4, 32x AB: bei 32x ist A gleißend, B im Westen extrem schwacher Lichtpunkt, gut 4-5 Größenklassen schwächer - bei 64x kann ich A ein wenig gebändigt erkennen und hat einen leichten Stich ins Gelbliche, B ist ordentlich abgesetzt
12.5" f/4.5, 45x AB: bei 45x ist Komponente B schwach sichtbar neben dem gelblich strahlenden 23 UMa - großer nicht abschätzbarer Helligkeitsunterschied

STF 1415 (**)

Name:	STF1415
Type:	**
Constellation:	UMa
Coordinates:	10h17m50.61s / +71°03'38.90"

Components:
		m₁	m₂	ρ	θ	Year
	AB	6m7	7m3	16.5"	168°	2019
	AC	6m7	10m8	153.3"	13°	2015

Robert Zebahl
70mm f/5.7, 22x AB: 2020-04-07: At 22x immediately noticeable as double star, medium bright with rather small difference in brightness. A appeared whitish, B slightly orange, partly brownish. At 44x similar color impression: A white-bluish, B slightly orange.
70mm f/5.7, 44x, Bortle 6, SQM-L 19.2 AB: 2021-04-03: At 12x easily separated, moderate brightness difference, unspectacular. At 44x, A appeared pale yellowish, B in very light blue. The color contrast was very subtle.
René Merting
12.5" f/4.5, 45x AB: bei 45x ein eng stehendes ordentlich getrenntes Paar - Komponente B im Süden wirkt weißgrau gegen die gut eine halbe Größenklasse hellere A-Komponente - das Paar sieht schick aus, es wird von drei schwächeren Sternen umrahmt

STF 1427 (**)

Name:	STF1427
Type:	**
Constellation:	UMa
Coordinates:	10h22m00.53s / +43°54'19.30"

Components:
	m₁	m₂	ρ	θ	Year
	8m2	8m5	9.3"	215°	2018

Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x very fine separated, but still tight. A very small difference in brightness was visible. At 44x also a nice view. In both magnifications I could see color differences: pale orange, grey-blue.

STF 1460 (**)

Name:	STF1460
Type:	**
Constellation:	UMa
Coordinates:	10h40m35.04s / +42°09'11.60"

Components:
	m₁	m₂	ρ	θ	Year
	8m7	8m9	3.9"	161°	2019

Robert Zebahl
70mm f/5.7, 57x, Bortle 6, SQM-L 19.6 2020-04-19: At 44x clearly visible as '8', overall quite faint and almost separated. The components seemed equally bright. At 57x separated, equally bright.

STF 1486 (**)

Name:	STF1486
Type:	**
Constellation:	UMa
Coordinates:	10h55m01.14s / +52°07'18.20"

Components:
	m₁	m₂	ρ	θ	Year
	8m4	9m7	31.6"	100°	2015

René Merting
100mm f/6.4, 20x bei 32x einfach, ordentliche Trennung - Komponente B im Osten ist halb so hell wie A - eigenartiger Farbkontrast, B wie so oft grau, aber A ist orangebraun - zurück auf 20x sind beide Sterne auch noch gut getrennt erkennbar

STF 1495 (**)

Name:	STF1495
Type:	**
Constellation:	UMa
Coordinates:	10h59m49.47s / +58°54'23.30"

Components:
	m₁	m₂	ρ	θ	Year
	7m2	8m8	34.2"	36°	2016

René Merting
100mm f/6.4, 20x bei 32x ein weit getrenntes Paar - Komponente B im NO ist knapp zwei Magnituden schwächer - A strahlend weiß, B die graue Maus, wie es sich gehört für die schwächere Komponente - zurück auf 20x immernoch ordentliche Trennung, der Helligkeitsunterschied wirkt nicht mehr ganz so groß
12.5" f/4.5, 45x bei 45x weit getrennt - ein schönes farbiges Kontrastpaar - Komponente B im NO ist gut 1.5 Größenklassen schwächer und strahlt kupfergrau, A dagegen ist weißgelb

STF 1505 (**)

Name:	STF1505
Type:	**
Constellation:	UMa
Coordinates:	11h05m41.23s / +62°37'01.50"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m9	10m6	8.2"	312°	2015
	AC	8m9	12m0	217.7"	177°	2015

Robert Zebahl
70mm f/5.7, 80x, Bortle 6, NELM 5m0+ AB: 2020-04-14: Easy split with pretty dim companion.

STF 1510 (**)

Name:	STF1510
Type:	**
Constellation:	UMa
Coordinates:	11h08m00.06s / +52°49'17.90"

Components:
	m₁	m₂	ρ	θ	Year
	7m7	9m0	5.7"	328°	2019



René Merting
100mm f/6.4, 64x bei 32x wirkt der Stern leicht länglich - bei 64x dann gelingt die Trennung - Komponente B hängt nordwestlich über A und ist mehr als eine Größenklasse schwächer - ein schönes enges Paar bei dieser Vergrößerung - B wirkt trotz des Größenunterschiedes nicht so schmutzig grau, wie es sonst immer ist

STF 1520 (**)

Name:	STF1520
Type:	**
Constellation:	UMa
Coordinates:	11h16m04.03s / +52°46'23.40"

Components:
	m₁	m₂	ρ	θ	Year
	6m5	7m8	12.4"	344°	2019

Robert Zebahl
70mm f/5.7, 44x 2020-04-08: At 22x pretty tight, uneven pair. A appeared orange, B did not show any clear color. At 44x, A appeared yellowish-orange, B silvery grey, partly grey-bluish.
René Merting
100mm f/6.4, 20x bei 32x ein knapp getrenntes Pärchen, auffällig im Umfeld - Komponente B ist eine Größenklasse schwächer - zurück auf 20x noch schönerer Eindruck, beider Sterne können noch ganz knapp getrennt voneinander gesehen werden

STF 1523 (**)

Name:	STF1523, xi UMa, 53 UMa, Alula Australis
Type:	**
Constellation:	UMa
Coordinates:	11h18m10.90s / +31°31'45.00"

Components:
		m₁	m₂	ρ	θ	Year
	AB	4m3	4m8	2.1"	155°	2019



Robert Zebahl
55mm f/9.1, 83x, Bortle 6-, SQM-L 19.1 2019-02-09: Already seen as '8' at 83x. At 125x the overlapping of both Airy disks was visible, but also a slight difference in brightness.
70mm f/5.7, 100x, Bortle 6 2018-02-18: Very close together with similar brightness. At first glance seen as an '8', looking closer I partly split both components. Similar view also at 128x.
70mm f/5.7, 133x 2020-03-15: Splendid sight! Beautifully separated with almost touching diffraction disks. The rather small difference in brightness was well visible. The diffraction rings of both components coalesced.
102mm f/11, 160x 2020-03-16: Awesome! Bright with lovely, subtle diffraction rings. The distance between both components is a smaller than the diameter of the diffraction disk of the fainter component.
120mm f/5, 168x, Bortle 6, SQM-L 19.1 2018-02-14: Well split with slight difference in brightness.
152mm f/5.9, 129x, Bortle 6, NELM 5m0+ 2019-02-06: Well split with visible difference in brightness. The colors of both components appeared equal.

STF 1544 (**)

Name:	STF1544
Type:	**
Constellation:	UMa
Coordinates:	11h31m18.57s / +59°42'03.30"

Components:
	m₁	m₂	ρ	θ	Year
	7m3	8m0	12.2"	91°	2016

Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x beautifully separated, moderately bright with visible difference in brightness. The components are still quite close together and appear white-bluish and slightly orange. At 31x same color impression.
René Merting
100mm f/6.4, 32x bei 32x der Prototyp des idealtypischen engen Doppelsternpaares - zwei schön aneinander geschmiegte Sterne, knapp getrennt - Komponente B im Osten ist eine halbe Größenklasse schwächer
12.5" f/4.5, 72x bei 72x ein gut getrenntes helles Pärchen - Komponente B ist maximal eine Dreiviertel Größenklasse schwächer - A strahlt chremeweiß, B kühler in der Ausstrahlung, deswegen ist ein kleiner feiner Farbkontrast erkennbar

STF 1546 (**)

Name:	STF1546
Type:	**
Constellation:	UMa
Coordinates:	11h32m20.34s / +56°05'43.30"

Components:
	m₁	m₂	ρ	θ	Year
	7m5	10m3	11.5"	349°	2015

Robert Zebahl
70mm f/5.7, 31x, Bortle 6, SQM-L 19.6 2020-04-19: Separated with a clear difference in brightness - the companion was rather dim. The primary component appeared creamy white.

STF 1553 (**)

Name:	STF1553
Type:	**
Constellation:	UMa
Coordinates:	11h36m35.69s / +56°08'07.30"

Components:
	m₁	m₂	ρ	θ	Year
	7m7	8m2	6.2"	165°	2018



Robert Zebahl
70mm f/5.7, 31x, Bortle 6, SQM-L 19.6 2020-04-19: At 22x medium bright double star with apparently similar bright components. At first sight visible as '8', on closer look separated. At 31x very fine split of the components with small difference in brightness. The two components appeared yellowish and slightly orange.
René Merting
12.5" f/4.5, 45x bei 45x sehe ich zwei fast gleich helle Sterne ganz eng beieinander stehen, da passt sprichwörtlich kein Blatt Papier dazwischen - bei 72x Helligkeitsunterschied eine knappe halbe Magnitude - ein ganz feiner Farbunterschied, Komponente A leicht weißgelblich, B im Osten wirkt ein bisschen grau

STF 1559 (**)

Name:	STF1559
Type:	**
Constellation:	UMa
Coordinates:	11h38m49.11s / +64°20'49.40"

Components:
	m₁	m₂	ρ	θ	Year
	6m8	8m0	2.0"	326°	2019

Robert Zebahl
70mm f/5.7, 133x, Bortle 6, NELM 5m0+ 2020-04-14: Two clearly visible, slightly touching diffraction disks. The fainter companion appeared somewhat more diffuse. Occasionally the double star appeared separated.

STF 1561 (**)

Name:	STF1561
Type:	**
Constellation:	UMa
Coordinates:	11h38m44.90s / +45°06'30.30"

Components:
		m₁	m₂	ρ	θ	Year
	AB	6m5	8m2	8.9"	247°	2019
	AC	6m5	9m5	176.8"	90°	2015
	AD	6m5	7m6	718.2"	76°	2015
	AE	6m5	12m1	60.7"	338°	2015



Robert Zebahl
70mm f/5.7, 44x AB: 2020-04-07: At 22x separated. The fainter companion is still very close to the primary component. At 44x beautiful sight with a clear difference in brightness. A: slightly yellowish, B: pale bluish.
70mm f/5.7, 31x, Bortle 6, SQM-L 19.6 AB: 2020-04-19: At 22x separated, but relatively tight together with significant difference in brightness. The pair stands close to 2 medium bright stars. Both components appear white. At 31x beautiful sight, the color of the components looks slightly different: white-yellowish with darker ( slightly orange?) companion.

STF 1579 (**)

Name:	STF1579, 65 UMa
Type:	**
Constellation:	UMa
Coordinates:	11h55m05.74s / +46°28'36.60"

Components:
		m₁	m₂	ρ	θ	Year
	AB-C	6m7	8m3	3.9"	43°	2019
	AB-D	6m7	7m0	62.5"	114°	2018

Robert Zebahl
55mm f/9.1, 83x, Bortle 6-, SQM-L 19.1 2019-02-09: AB, C & D easy to split, but the faint C component only appeared as a tiny star. To the south there is the brighter D component.
B 8x40 AB-D: 2020-04-05: Immediately conspicuous in the field. Medium bright double star with slightly uneven components. Western component AB appeared slightly orange, component D tended to be bluish.
55mm f/9.1, 27x, Bortle 6-, SQM-L 19.1 AB-D: Easy to separate with large distance and very small difference in brightness. The D component showed a bluish tint, the lighter one (AB) a slightly yellowish tint. At higher magnification also the faint C component is visible.

STF 1600 (**)

Name:	STF1600
Type:	**
Constellation:	UMa
Coordinates:	12h05m34.42s / +51°55'52.20"

Components:
	m₁	m₂	ρ	θ	Year
	7m6	8m3	7.8"	92°	2015

Robert Zebahl
70mm f/5.7, 44x, Bortle 6, SQM-L 19.6 2020-04-19: Uneven pair. At 22x medium bright and still pretty tight. At 44x beautiful sight: pale orange, grey-bluish.

STF 1603 (**)

Name:	STF1603
Type:	**
Constellation:	UMa
Coordinates:	12h08m07.07s / +55°27'50.70"

Components:
		m₁	m₂	ρ	θ	Year
	AB	7m8	8m3	22.6"	84°	2019

Robert Zebahl
70mm f/5.7, 22x 2020-04-07: At 22x quite apparent double star in rather poor surrounding. Nice separation with little difference in brightness. Primary component appeared slightly orange, companion grey-bluish. At 44x similar view in color appearance.
René Merting
12.5" f/4.5, 45x bei 45x gut getrennt - Komponente B im Osten wirkt grauorange gegen die weiß strahlende Komponente A - Helligkeitsunterschied eine halbe Größenklasse - ein schön isoliert stehendes Sternpaar

STF 1608 (**)

Name:	STF1608
Type:	**
Constellation:	UMa
Coordinates:	12h11m27.76s / +53°25'17.50"

Components:
		m₁	m₂	ρ	θ	Year
	AB	8m1	8m3	13.5"	221°	2019



Robert Zebahl
70mm f/5.7, 22x, Bortle 6, SQM-L 19.6 2020-04-19: Easy to find, medium bright. At 22x quite conspicuous with rather small difference in brightness. A difference in color is clearly visible: slightly orange, white-bluish. At 31x nice color contrast with a little more intensive colors: light orange & light blue.
René Merting
12.5" f/4.5, 72x bei 72x ein schönes helles Pärchen, beide Komponenten sind gleich hell und zahncremeweiß

STF 1695 (**)

Name:	STF1695
Type:	**
Constellation:	UMa
Coordinates:	12h56m17.64s / +54°05'58.10"

Components:
		m₁	m₂	ρ	θ	Year
	AB	6m0	7m8	3.9"	281°	2017
	AC	6m0	12m3	131.7"	139°	2015

Robert Zebahl
70mm f/5.7, 57x, Bortle 6- AB: Easily separable, but still quite close together with a relatively large difference in brightness. The companion appeared only as a tiny star.

STF 1820 (**)

Name:	STF1820
Type:	**
Constellation:	UMa
Coordinates:	14h13m00.76s / +55°19'31.10"

Components:
	m₁	m₂	ρ	θ	Year
	9m1	9m4	2.8"	123°	2019



René Merting
12.5" f/4.5, 144x bei 72x ist ein Stäbchen mit einer angedeuteten Einschnürung erkennen - bei 144x sind beide Komponenten getrennt voneinander sichtbar - beide sind gleich hell

STF 1830 & STF 1831 (**)

Name:	STF1830 & STF1831, WDS14161+5643
Type:	**
Constellation:	UMa
Coordinates:	14h16m08.47s / +56°42'45.70"

Components:
		m₁	m₂	ρ	θ	Year
STF1831	AB	7m2	9m6	5.8"	138°	2017
STF1831	AC	7m2	6m7	112.2"	219°	2017
STF1831	CD	6m7	13m1	112.1"	116°	2016
STF1830	CE	6m7	9m3	138.0"	245°	2016
STF1830	EF	9m3	10m3	10.6"	312°	2017
STF1830	EG	9m3	12m2	35.2"	81°	2017

Robert Zebahl
70mm f/5.7, 57x, Bortle 6 2020-04-11: At 22x the components AB, C, E & F are well visible and widely separated. E & F are comparatively faint. The C component in the middle appeared white-yellowish, AB rather white with a slight tendency to blue. At 57x, the pair AB with a clear difference in brightness can be easily split. An altogether rewarding and unusual multiple system.
B 8x40 STF1831 (AC): 2020-04-05: Fairly wide pair with slight differences in brightness and color. C appeared slightly orange, A on the other hand slightly bluish. Comparatively bright double star, which gives a nice view.
55mm f/9.1, 27x STF1831 (AC): 2020-04-05: Moderate difference in brightness. C: pale orange, A: subtle blue.
René Merting
12.5" f/4.5, 72x EF: bei 72x ein schwaches Sternpaar, gut getrennt - E ist gelblich, F eine halbe Größenklasse schwächer und grau EG: bei 72 ist nordöstlich von EF noch ein ganz schwacher Lichtpunkt erkennbar - G hat ungefähr mit dreifachem Abstand EF
12.5" f/4.5, 72x AB: bei 144x ist B ein bisschen mehr als knapp getrennt im SO von A erkennbar - B ist deutlich schwächer und grau gegen den weißgelblich strahlenden A - zurück auf 72x kann ich die beiden auch noch extrem knapp getrennt erkennen in guten Momenten - ein schönes Doppel zusammen mit STF1830 EF AC: bei 72x fällt die helle Komponente C im Südwesten von AB zwar auf, ich hätte aber nicht vermutet, dass der Stern dazu gehört

STT 241 (**)

Name:	STT241
Type:	**
Constellation:	UMa
Coordinates:	11h56m17.24s / +35°26'53.30"

Components:
	m₁	m₂	ρ	θ	Year
	6m8	8m7	1.8"	147°	2017



Robert Zebahl
120mm f/5, 200x, Bortle 6-, SQM-L 19.0 2021-04-04: Well separated with noticeable difference in brightness.

STT 575 (**)

Name:	STT575, 62 UMa
Type:	**
Constellation:	UMa
Coordinates:	11h41m34.26s / +31°44'45.80"

Components:
		m₁	m₂	ρ	θ	Year
	AB	5m8	9m8	44.0"	311°	2018

René Merting
100mm f/6.4, 32x bei 32x habe ich B zunächst suchen müssen - Komponente A ist schön hell, B zeigt sich in ordentlichem Abstand nordwestlich von A, Helligkeitsunterschied 3 Magnituden - zurück auf 20x kann ich B auch noch wahrnehmen, aber nur weil ich wusste, wohin ich schauen muss

Winnecke 3 (**)

Name:	Winnecke 3, WNC3
Type:	**
Constellation:	UMa
Coordinates:	11h18m58.50s / +51°18'12.70"

Components:
	m₁	m₂	ρ	θ	Year
	9m0	10m5	6.7"	209°	2019

René Merting
12.5" f/4.5, 72x Zenitbeobachtung - bei 72x ist Komponente B mit leichtem Abstand getrennt von A erkennbar - Helligkeitsunterschied zwei Größenklassen - Komponente A wirkt gelblich, B kommt ohne Farbe aus, das reicht aber für einen kleinen feinen Farbkontrast

WX UMa (**)

Name:	WX UMa
Type:	**
Constellation:	UMa
Coordinates:	11h05m27.65s / +43°31'38.70"

Components:
		m₁	m₂	ρ	θ	Year
VBS18	AB	8m8	14m6	32.0"	125°	2017
CSN7	AC	4m8	7m5	7.3"	168°	2003

Robert Zebahl
70mm f/5.7, 100x, Seeing 3-4/5 AC: 2020-03-31: Not identifiable at magnifications between 22x and 100x. WX UMa (component A?) is a variable (b14m2-16m53) and probably too faint.

zeta UMa (**)

Name:	zeta UMa
Type:	**
Constellation:	UMa
Coordinates:	13h23m55.42s / +54°55'31.50"

Components:
		m₁	m₂	ρ	θ	Year
STF1744, 79 UMa, Mizar	AB	2m2	3m9	14.6"	154°	2019
STF1744, Mizar & Alcor	AC	2m2	4m0	707.7"	72°	2017
SMR4	AD	2m2	7m6	492.8"	102°	2017

Robert Zebahl
102mm f/11, 28x First pastel sketch (Pitt pastel by Faber-Castell) of a double star on black paper, where also the halos were sketched around the stars. The stars themselves were redrawn with an Edding (Edding 1500, Soft Pastel white). The sketch shows the components A to D.
B 8x40 AB: 2020-04-05: Even with tripod not separable.
70mm f/5.7, 10x AB: 2020-04-12: Observation from city with a 70/400mm ED refractor, for which I made aperture masks from 10mm to 60mm. Goal was to find the minimum magnification for a successful split. 70mm: At 12.5x no separation of the components possible due to outshining. Grey filters brought a slight improvement, but again no separation or elongation was visible. 60mm: At 12.5x slight outshining of the companion, clearly elongated and almost separated. 50mm: At 12.5x the companion was almost outshined. A separation was just possible. 40mm: At 12.5x both components appear finely separated from each other. 30mm: At 10x not clearly separable due to outshining, but clearly elongated. At 12.5x then quite easy to separate with a fine star rendition. 20mm: At 10x the companion is still clearly visible, but quite close to the primary component. At 12.5x best view under the used apertures with a very fine rendition! 10mm: At 10x the companion appears very faint. Separation possible, but extremely tight. At 12.5x reasonably well separated.
70mm f/5.7, 22x, Bortle 6 AB: 2020-04-11: At 12x no separation possible, because the bright primary component outshines the companion. At 22x clearly separated, but still quite close together.
René Merting
B 8x30 AC: ein ultraweit getrenntes Pärchen - Komponente C im NO schätze ich eine Größenklasse schwächer ein (1.78 mag laut stelle Doppie) - Komponente D (SMR4) ist östlich der beiden Sterne ganz schwach erkennbar, D steht dabei näher zu C