- Double Stars (Gem) -

And (60) Cep (28) Cyg (98) Leo (35) Peg (43) SGE (1)
Aql (58) Cet (5) Del (16) Lep (7) Per (37) Sgr (11)
Aqr (4) CMa (6) Dra (27) Lib (4) Psc (18) Tau (19)
Ari (8) CMi (3) Equ (7) LMi (6) Pup (3) Tri (10)
Aur (32) Cnc (14) Eri (6) Lyn (18) Sco (5) UMa (47)
Boo (32) Com (13) Gem (33) Lyr (32) Sct (5) UMi (5)
Cam (17) CrB (10) Her (59) Mon (14) Ser (22) Vir (20)
Cap (7) Crv (4) Hya (11) Oph (18) Sex (6) Vul (12)
Cas (42) CVn (15) Lac (13) Ori (39) Sge (8)

3 Gem (**)

Name: 3 Gem
Type: **
Constellation: Gem
Coordinates: 06h09m43.99s / +23°06'48.50"

Components:
m1 m2 ρ θ Year
AB 5m.9 8m.5 0.6" 347° 2008
AC 5m.8 14m.4 18.8" 63° 2015
Robert Zebahl
152mm f/8, 240x, Bortle 6-, SQM-L 19.2, Seeing 3/5
AB: 2022-02-27: At 240x and 300x nothing visible which indicates a double star. Just average seeing.

A 1061 & STF 1000 (**)

Name: A1061 & STF1000
Type: **
Constellation: Gem
Coordinates: 06h59m21.15s / +25°14'00.20"

Components:
m1 m2 ρ θ Year
STF1000 AB-C 8m.1 9m.0 22.1" 67° 2016
A1061 AB 8m.9 9m.1 0.6" 42° 1999

../images/binary-star-orbits/A1061-AB-orbit.jpg

Robert Zebahl
152mm f/8, 30x, Bortle 6-, SQM-L 19.2, Seeing 3/5
STF1000 (AB-C): 2022-02-27: At 30x quite conspicuous, medium bright double star with nice separation. AB appears pale yellowish, the color of the slightly fainter companion C cannot be defined. The color impression remains even at 92x.

René Merting
100mm f/6.4, 32x
STF1000 (AB-C): bei 32x ein bequem getrenntes Pärchen - Komponente AB kühlweiß - Komponente C im Osten ist eine dreiviertel Größenklasse schwächer und grauweiß

BU 1008 (**)

Name: BU1008, eta Gem, 7 Gem, Propus
Type: **
Constellation: Gem
Coordinates: 06h14m52.69s / +22°30'24.60"

Components:
m1 m2 ρ θ Year
3m.5 6m.2 1.8" 258° 2020

../images/binary-star-orbits/BU1008-orbit.jpg

Robert Zebahl
152mm f/5.9, 225x, Bortle 6, SQM-L 19.3, Seeing 3/5
Already comparatively easy at 180x. The faint companion can be seen well as a quite distinct, slightly elongated, partly round brightening. At 225x and above it becomes easy and immediately apparent, even if the diffraction rings of the primary component are not permanently visible due to the seeing. The primary component was shining in a bright orange.

ES 2625 & S 548 (**)

Name: ES2625 & S548
Type: **
Constellation: Gem
Coordinates: 07h27m40.54s / +22°08'29.30"

Components:
m1 m2 ρ θ Year
ES2625 AB 7m.0 12m.4 11.9" 24° 2015
S548 AC 7m.0 8m.9 35.3" 277° 2019
René Merting
100mm f/6.4, 20x
S548 (AC): bei 32x ein weit getrenntes Paar - Komponente A strahlt schwach gelblich … eher dunkelgelb - Komponente C im Westen von A ist gut 1.5 Magnituden schwächer und dunkelgrau bis lachsorange - der Doppelstern steht isoliert, fällt aber nicht übermäßig auf - zurück auf 20x ist das Paar weiterhin gut getrennt erkennbar

HJ 3288 (**)

Name: HJ3288
Type: **
Constellation: Gem
Coordinates: 07h02m18.43s / +12°34'54.20"

Components:
m1 m2 ρ θ Year
7m.3 8m.7 38.5" 247° 2015
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
Easy to separate with moderate angular distance and a significant difference in brightness. Slight difference in color: white-yellowish, slightly orange. Nice view together with the double star STF1007 and HD52976, which appears in a bright orange. Sketched together with STF1007.

../sketches/2019-12-18_stf1007_hj3288.jpg

S 513 (**)

Name: S513
Type: **
Constellation: Gem
Coordinates: 06h21m14.48s / +21°07'56.70"

Components:
m1 m2 ρ θ Year
AB 7m.3 8m.9 59.7" 258° 2016
AC 7m.3 12m.0 47.4" 250° 2016
AD 7m.3 7m.6 264.9" 24° 2015
AE 7m.3 11m.3 83.8" 285° 2016
BE 8m.9 11m.3 40.7" 327° 2015
BT 8m.9 12m.2 37.8" 295° 2014
René Merting
B 18x70
AB: weit getrenntes Pärchen - Komponente B im Westen ist gut 1.5 Größenklassen schwächer und wirkt dadurch bräunlich ggü. der weiß schimmernden Komponente A

100mm f/6.4, 20x
AB: bei 32x popeleinfach, weit getrennt - Komponente B im Westen ist gut 1.5 Magnituden schwächer - zurück auf 20x nach wie vor sehr einfach, ein unauffälliger Doppelstern

S 524 (**)

Name: S524
Type: **
Constellation: Gem
Coordinates: 06h34m07.10s / +22°07'27.20"

Components:
m1 m2 ρ θ Year
AB 7m.2 7m.4 53.0" 244° 2017
Robert Zebahl
152mm f/8, 30x, Bortle 6-, SQM-L 19.2, Seeing 3/5
2022-02-27: Pretty bright, wide double star with small difference in brightness. Both components appear white.

René Merting
B 18x70
AB: popeleinfach mit dem FG - ein mehr als gut getrenntes Pärchen zweier gleich heller Sterne - die östliche Komponente wirkt ein klein wenig heller - A warmweiß, B blauweiß

100mm f/6.4, 20x
AB: bei 32x zeigen sich zwei annähernd gleichhelle Sterne weit getrennt voneinander - Komponente B im SW wirkt kühler als A
AC: bei 32x ist südöstlich von A in doppeltem Abstand wie AB eine weitere Komponente erkennbar - C ist mindestens 2 Größenklassen schwächer als B - alle drei Sterne bilden ein schönes rechtwinkliges Dreieck, wobei die Ecke von A den rechten Winkel bildet - zurück auf 20x ist C auch noch knapp sichtbar

S 529 (**)

Name: S529
Type: **
Constellation: Gem
Coordinates: 06h37m33.90s / +12°10'50.00"

Components:
m1 m2 ρ θ Year
AB 6m.9 9m.3 52.7" 130° 2019
AC 6m.9 8m.1 143.5" 165° 2012
René Merting
B 18x70
AB: ein weit getrenntes Sternpaar - Komponente B im SO ist kupferbraun, die gut 2 bis 2.5 Größenklassen hellere Komponente A strahlt weiß

SHJ 70 (**)

Name: SHJ70, 15 Gem
Type: **
Constellation: Gem
Coordinates: 06h27m46.58s / +20°47'22.60"

Components:
m1 m2 ρ θ Year
AB 6m.7 8m.2 24.7" 203° 2019
AC 6m.7 12m.7 85.6" 35° 2015
Robert Zebahl
B 16x70
AB: 2021-02-22: Clearly split with noticeable difference in brightness. Pale orange with much fainter companion. Together with Nu Gem & 16 Gem in a nice curved star chain.

René Merting
B 18x70
AB: ein schönes enges Sternpaar, Komponente B ist SW ist ordentlich getrennt von A zu erkennen - etwas über eine Größenklasse Helligkeitsunterschied, dadurch leichter Farbkontrast

STF 889 (**)

Name: STF889
Type: **
Constellation: Gem
Coordinates: 06h19m51.77s / +25°00'49.10"

Components:
m1 m2 ρ θ Year
AB 7m.6 9m.9 21.4" 245° 2017
René Merting
B 18x70
mit etwas Konzentration sind beide Sterne getrennt zu erkennen - A und B sind halb so weit voneinander entfernt wie das nahe liegende Pärchen STTA74 - Komponente B im SW ist genauso schwach wie B bei STTA74, aber dadurch, dass er näher zum Hauptstern steht, ist er schwächer sichtbar

100mm f/6.4, 32x
bei 32x unscheinbarer als der 14' nordöstlich liegende STTA74 - die Komponenten von STF889 wirken beide schwächer als die von STTA74 - Komponente B im SW ist gerade so erkennbar, Helligkeitsunterschied mindestens 2 Größenklassen, B ist gut abgesetzt von A - Farbkontrast gelblich, B farblos

STF 899 (**)

Name: STF899
Type: **
Constellation: Gem
Coordinates: 06h22m49.64s / +17°34'27.30"

Components:
m1 m2 ρ θ Year
7m.4 8m.0 2.2" 17° 2019
Robert Zebahl
70mm f/5.7, 133x
Separated, but tight with visible difference in brightness.

STF 924 (**)

Name: STF924, 20 Gem
Type: **
Constellation: Gem
Coordinates: 06h32m18.52s / +17°47'03.40"

Components:
m1 m2 ρ θ Year
AB 6m.3 6m.9 19.9" 212° 2019
BC 6m.9 13m.0 47.8" 144° 2014
Robert Zebahl
B 16x70
AB: 2021-02-22: Easy to separate with small difference in brightness. Conspicuous double star. White-yellowish & white-bluish.

70mm f/5.7, 22x
AB: At 22x bright, immediately conspicuous, although in a relatively star-rich surrounding. Moderate but beautiful color contrast: bright orange, subtle blue. Also at 44x very beautiful sight.

152mm f/5.9, 69x, Bortle 6, SQM-L 19.3, Seeing 3/5
AB: Easy, bright, moderately uneven. Nice contrast in color: slight orange, white-bluish.

René Merting
B 18x70
AB: das dicht stehende Paar fällt sofort ins Auge - Komponente A im Norden ist vielleicht eine halbe Magnitude heller als Komponente B, die leicht gräulich strahlt

STF 932 (**)

Name: STF932
Type: **
Constellation: Gem
Coordinates: 06h34m21.57s / +14°45'08.30"

Components:
m1 m2 ρ θ Year
8m.3 8m.5 1.6" 305° 2019

../images/binary-star-orbits/STF932-orbit.jpg

Robert Zebahl
70mm f/5.7, 150x
Unfortunately a nearby lamp bothered me. I could see the double star at least elongated.

STF 957 (**)

Name: STF957
Type: **
Constellation: Gem
Coordinates: 06h45m10.02s / +30°49'33.50"

Components:
m1 m2 ρ θ Year
AB 7m.5 9m.4 3.6" 91° 2019
AC 7m.5 13m.8 19.3" 100° 2015
Robert Zebahl
70mm f/5.7, 100x
AB: Too faint for a separation. Primary component visible, companion not. Used magnifications from 67x to 133x. Observation from city at moon (83%).

152mm f/5.9, 129x, Bortle 6, SQM-L 19.3, Seeing 3/5
AB: Easy with significant difference in brightness and moderate angular distance.

STF 982 (**)

Name: STF982, 38 Gem
Type: **
Constellation: Gem
Coordinates: 06h54m38.63s / +13°10'40.10"

Components:
m1 m2 ρ θ Year
AB 4m.8 7m.8 7.3" 145° 2018

../images/binary-star-orbits/STF982-AB-orbit.jpg

Robert Zebahl
55mm f/9.1, 27x
At 27x pretty tight with much fainter component. At 71x clearly separated with clear difference in brightness. Brighter component appeared slightly yellowish, the weaker one slightly bluish.

70mm f/5.7, 33x
Easy to separated with noticeable difference in brightness. The fainter component appeared slightly orange, the brighter one rather white.

STF 991 (**)

Name: STF991
Type: **
Constellation: Gem
Coordinates: 06h57m01.26s / +24°57'27.90"

Components:
m1 m2 ρ θ Year
AB 8m.0 9m.2 3.8" 165° 2019
AC 8m.0 10m.6 134.0" 202° 2017
CD 10m.6 11m.1 13.2" - 2017
Robert Zebahl
152mm f/8, 92x, Bortle 6-, SQM-L 19.2, Seeing 3/5
AB: 2022-02-27: Nice, obvious double star with moderate difference in brightness. The components are still relatively close together, but easily separable. The primary component appears bright orange with a faint companion.

STF 1007 (**)

Name: STF1007
Type: **
Constellation: Gem
Coordinates: 07h00m37.12s / +12°43'24.20"

Components:
m1 m2 ρ θ Year
AB 7m.4 11m.4 14.6" 300° 2015
AC 7m.4 10m.0 21.9" 244° 2015
AD 7m.4 7m.7 67.7" 28° 2016
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
AD: Wide separation, small difference in brightness. Slight difference in color, but difficult to describe. Component A at least seemed rather white. South of STF1007 there is also the double star HJ3288 and the star HD52976, which appears in a bright orange. Together in one field of view a beautiful sight.

../sketches/2019-12-18_stf1007_hj3288.jpg

STF 1035 (**)

Name: STF1035
Type: **
Constellation: Gem
Coordinates: 07h12m01.06s / +22°16'44.50"

Components:
m1 m2 ρ θ Year
8m.1 8m.4 8.7" 40° 2018
Robert Zebahl
B 16x70
2021-02-22: Separate, but very close together. Small difference in brightness visible.

STF 1066 (**)

Name: STF1066, delta Gem, 55 Gem
Type: **
Constellation: Gem
Coordinates: 07h20m07.39s / +21°58'56.40"

Components:
m1 m2 ρ θ Year
3m.5 8m.2 5.5" 229° 2018

../images/binary-star-orbits/STF1066-orbit.jpg

Robert Zebahl
55mm f/9.1, 71x
Large difference in brightness. The fainter component was well separated, but just a very tiny star.

102mm f/11, 160x, Bortle 7, SQM-L 18.8, Seeing 3-4/5
Easy to separate with relatively large distance. The companion appeared as a tiny, faint star.

STF 1081 (**)

Name: STF1081
Type: **
Constellation: Gem
Coordinates: 07h24m08.94s / +21°27'28.00"

Components:
m1 m2 ρ θ Year
AB 7m.7 8m.5 1.9" 234° 2019
AC 7m.7 9m.9 107.0" 63° 2017
Robert Zebahl
102mm f/11, 86x, Bortle 6
AB: At 86x just separated, very close together with moderate difference in brightness. In relation to A, the components B & C are almost opposite each other. At 125x, A & B are easy to split.

102mm f/11, 28x, Bortle 6
AC: Rather wide apart from component A with noticeable difference in brightness. Less conspicuous.

STF 1083 (**)

Name: STF1083
Type: **
Constellation: Gem
Coordinates: 07h25m35.30s / +20°29'42.60"

Components:
m1 m2 ρ θ Year
7m.3 8m.1 6.9" 226° 2019
Robert Zebahl
70mm f/5.7, 22x
Unequal pair. At 22x very tight, at 44x well split. Fainter companion appeared slightly orange, brighter one white-bluish.

STF 1094 (**)

Name: STF1094
Type: **
Constellation: Gem
Coordinates: 07h27m25.99s / +15°18'59.00"

Components:
m1 m2 ρ θ Year
7m.6 8m.5 2.5" 97° 2019
Robert Zebahl
70mm f/5.7, 57x
At 57x barely split with noticeable difference in brightness. At 100x well split, but still tight.

STF 1108 (**)

Name: STF1108
Type: **
Constellation: Gem
Coordinates: 07h32m50.63s / +22°53'15.40"

Components:
m1 m2 ρ θ Year
6m.6 8m.2 11.7" 179° 2019
Robert Zebahl
B 16x70
2021-02-22: Separated with clearly visible brightness difference. The primary component appeared whitish, the companion appeared slightly separated only as a very faint tiny star.

René Merting
100mm f/6.4, 32x
bei 32x ein sehr ungleiches enges Paar, aber klar getrennt - Komponente B im Süden ist knapp zwei Größenklassen schwächer - Komponente A buttergelb - zurück auf 20x verschmilzt Komponente B förmlich mit A zu einer sehr ungleichen 8, in guten Momenten sind beide Sterne aber dennoch schon getrennt sichtbar

STF 1110 (**)

Name: STF1110, alpha Gem, 66 Gem, Castor
Type: **
Constellation: Gem
Coordinates: 07h34m35.86s / +31°53'17.80"

Components:
m1 m2 ρ θ Year
AB 1m.9 3m.0 5.4" 53° 2020
AC 1m.9 9m.8 71.6" 164° 2020
AD 1m.9 10m.1 179.8" 221° 2017

../images/binary-star-orbits/STF1110-AB-orbit.jpg

Robert Zebahl
55mm f/9.1, 27x
AB: At 27x slight difference in brightness visible. Double star appeared as '8'. At 38x clearly split, but tight.

63mm f/13.3, 26x
AB: Experiment to determine the smallest magnification to separate Castor. I observed on 2022-05-09, 2022-05-11 & 2022-05-18.
At 26x and 30x easily seen as a double star, but not clearly separable due to outshining. At 70x of course easily separated. Stopped down to 30mm aperture, Castor appeared partially separated at 26x, but very barely. The right viewing position at the eyepiece was important. At 30x with 30mm aperture, Castor was cleanly separated, but extremely tight.
Following a hint from Christopher Hay, I also used a red filter from Baader to avoid outshining at full aperture. Now also a separation at 26x was possible, whereby the components were extremely close to each other.
For me a magnification of 26x seems to be the minimum to separate Castor cleanly, if the brightness of the components is reduced sufficiently.

70mm f/5.7, 44x, Bortle 6
AB: At 44x the double star appeared as an '8'. At 100x clearly split with noticeable difference in brightness. Both components appeared white.

René Merting
100mm f/6.4, 107x
AB: bei 32x wirkt der Stern leicht länglich - bei 107x stehen die beiden Sterne schön eng mit überlagernden Beugungsscheibchen, die Komponenten sind dennoch getrennt erkennbar - Komponente B im Osten ist eine halbe Magnitude schwächer - ganz schwacher Farbkontrast

STF 1140 (**)

Name: STF1140
Type: **
Constellation: Gem
Coordinates: 07h48m22.61s / +18°20'12.40"

Components:
m1 m2 ρ θ Year
7m.0 8m.7 6.4" 273° 2016
Robert Zebahl
70mm f/5.7, 44x
Easy to separate with quite clear difference in brightness.

STT 134 & WAL 42 (**)

Name: STT134 & WAL42
Type: **
Constellation: Gem
Coordinates: 06h09m15.94s / +24°25'40.30"

Components:
m1 m2 ρ θ Year
STT134 AB 7m.5 9m.1 31.2" 189° 2016
WAL42 AD 7m.5 12m.6 43.8" 251° 2015
Located in the northern part of Messier 35.

Robert Zebahl
152mm f/8, 92x, Bortle 6-, SQM-L 19.2, Seeing 3/5
2022-02-27: At 30x the uneven pair AB appears widely separated. A shines in a glaring bright orange, B in the south appears slightly bluish. Then at 92x component D is also very faintly visible. All three components form an acute-angled, nearly isosceles triangle. Also at this magnification A appears bright orange, B gray-bluish. At 171x D still remains pretty faint.

René Merting
100mm f/6.4, 32x
STT134 (AB): bei 32x zeigt sich südlich von A ein gut 1.5 Magnituden schwächerer Begleiter - ein ordentlich getrenntes Pärchen - im Umfeld nicht sehr auffällig (logisch bei einem Doppelstern in M 35)

STT 167 (**)

Name: STT167
Type: **
Constellation: Gem
Coordinates: 07h13m30.95s / +32°08'43.70"

Components:
m1 m2 ρ θ Year
AB 7m.4 10m.9 5.1" 163° 2017
Robert Zebahl
70mm f/5.7, 133x
Too faint for a separation. Primary component visible, no sign of the companion. Observation from city at moon (83%).

152mm f/5.9, 270x, Bortle 6, SQM-L 19.3, Seeing 3/5
At a position angle of about 180° I sometimes had the feeling to see something of the faint companion, but not sure.

STT 179 (**)

Name: STT179, kappa Gem, 77 Gem
Type: **
Constellation: Gem
Coordinates: 07h44m26.87s / +24°23'53.30"

Components:
m1 m2 ρ θ Year
3m.7 10m.0 7.2" 243° 2019
Robert Zebahl
70mm f/5.7, 133x
Observation at nearly full moon: Fainter companion was not visible.

120mm f/5, 200x, Bortle 6-, SQM-L 18.9
Although the optics were not yet completely cooled down, the fainter component could be seen slightly outside the first diffraction ring as a tiny star in moments of steady air.

René Merting
100mm f/6.4, 213x
bei 213x mit viel Geduld ist blickweise Komponente B südwestlich von A im Beugungsscheibchen erkennbar - kaum wie ein Stern, einfach nur eine schwache Aufhellung

STTA 74 (**)

Name: STTA74
Type: **
Constellation: Gem
Coordinates: 06h20m36.35s / +25°11'20.40"

Components:
m1 m2 ρ θ Year
AB 7m.1 8m.9 57.4" 265° 2015
AC 7m.1 12m.0 41.5" 291° 2015
René Merting
B 18x70
AB: westlich von Komponente A blinkt in ziemlich weitem Abstand die viel schwächere Komponente B hervor - A ist reinweiß, B wirkt grau

100mm f/6.4, 32x
AB: bei 32x weit getrennt - Komponente B im SW ist 1.5 Magnituden schwächer und wirkt farblos gegen die weiß strahlende Komponente A

STTA 75 (**)

Name: STTA75
Type: **
Constellation: Gem
Coordinates: 06h20m34.48s / +18°02'56.70"

Components:
m1 m2 ρ θ Year
7m.7 8m.9 47.2" 130° 2020
René Merting
B 18x70
ein mit ordentlichem Abstand getrenntes Sternpaar - B im SO ist halb so hell wie A

STTA 80 (**)

Name: STTA80
Type: **
Constellation: Gem
Coordinates: 06h58m06.59s / +14°13'43.40"

Components:
m1 m2 ρ θ Year
AB 7m.2 7m.4 124.1" 53° 2015
AC 7m.2 8m.4 81.2" 112° 2015
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
All 3 components form a striking triangle and are slightly different in color. A (western component): white-bluish; B (northern component): white-yellowish; C (southern component): orange, partly slightly reddish.

../sketches/2019-12-18_stta80.jpg

STTA 83 & HO 519 (**)

Name: STTA83 & HO519
Type: **
Constellation: Gem
Coordinates: 07h09m35.47s / +25°43'44.70"

Components:
m1 m2 ρ θ Year
HO519 AB 7m.2 13m.0 32.5" 73° 2015
STTA83 AC 7m.2 7m.8 123.3" 79° 2015
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
STTA83 (AC): Wide pair, relatively bright, moderate difference in brightness. A: slightly orange; C: grey-blue. Southeast of the pair in a much larger distance there is another, fainter star, which appears orange, partly reddish. It does not belong to the system. All three stars form a beautiful right-angled triangle.

STTA 89 (**)

Name: STTA89
Type: **
Constellation: Gem
Coordinates: 07h51m00.20s / +31°36'48.70"

Components:
m1 m2 ρ θ Year
6m.8 7m.7 76.6" 84° 2017
Robert Zebahl
70mm f/5.7, 22x
At 22x widely separated with moderate difference in brightness. The primary component appeared whitish, at 44x rather white-yellowish. The companion appeared slightly orange.