- 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

../images/binary-star-orbits/BU1077-AB-orbit.jpg

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

../images/binary-star-orbits/HJ2477-A-BC-orbit.jpg ../images/binary-star-orbits/HU628-BC-orbit.jpg

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" 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

../images/binary-star-orbits/STF1280-AB-orbit.jpg

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

../images/binary-star-orbits/STF1306-AB-orbit.jpg

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

../images/binary-star-orbits/STF1321-AB-orbit-solution-1.jpg ../images/binary-star-orbits/STF1321-AB-orbit-solution-2.jpg

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.

../sketches/2020-04-13_stf1331.jpg

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.

../sketches/2020-03-18_stf1350_c2019_y4_atlas.jpg

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

../images/binary-star-orbits/STF1510-orbit.jpg

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

../images/binary-star-orbits/STF1523-AB-orbit.jpg

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.

../sketches/2019-02-09_xi_uma.jpg

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

../images/binary-star-orbits/STF1553-orbit-solution-1.jpg ../images/binary-star-orbits/STF1553-orbit-solution-2.jpg

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.

../sketches/2020-04-14_stf1559.jpg

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

../images/binary-star-orbits/STF1561-AB-orbit.jpg

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.

../sketches/2019-02-09_65_uma.jpg

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

../images/binary-star-orbits/STF1608-AB-orbit.jpg

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

../images/binary-star-orbits/STF1820-orbit.jpg

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.

../sketches/2020-04-11_stf1830_stf1831.jpg

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

../images/binary-star-orbits/STT241-orbit.jpg

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.

../sketches/2019-08-14_mizar_alcor.jpg

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