- Double Stars (Boo) -

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

mu Boo (**)
Name: mu Boo, 51 Boo, Alkalurops
Type: **
Constellation: Boo
Coordinates: 15h24m29.54s / +37°22'37.10"

Components:
m1 m2 ρ θ Year
CHR181, mu 1 Boo Aa-Ab 4m3 None 0.1" 188° 2012
STFA28, mu 1 Boo AB 4m3 7m1 109.0" 172° 2018
STF1938, mu 2 Boo Ba-Bb 7m1 7m6 2.3" 3° 2019

../images/binary-star-orbits/CHR181-Aa-Ab-orbit.jpg ../images/binary-star-orbits/STF1938-Ba-Bb-orbit.jpg

Robert Zebahl
B 8x40, Bortle 7, NELM 5m0, SQM-L 19.2
STFA28 (AB): Easily split with obvious difference in brightness.
70mm f/5.7, 22x, Bortle 6, SQM-L 19.2
STFA28 (AB): Evident, very wide apart and unequal. A: white-yellowish, B: grey.
102mm f/11, 125x, Bortle 6-, SQM-L 19.2
STF1938 (Ba-Bb): Beautiful view! This triple system includes STFA 28 and STF 1938.

../sketches/2019-04-04_mu_boo.jpg

120mm f/5, 23x, Bortle 6, NELM 5m0+, SQM-L 19.4
STFA28 (AB): Easy to split with large angular distance and noticeable difference in brightness.

S 656 (**)
Name: S656
Type: **
Constellation: Boo
Coordinates: 13h50m23.51s / +21°16'35.80"

Components:
m1 m2 ρ θ Year
6m9 7m4 86.2" 209° 2018
Robert Zebahl
B 8x40
2020-04-05: Wide, medium bright pair. Primary component appeared slightly orange, the companion greyish. The double star is in close vicinity to the star 6 Boo, which shines in a pale orange.
70mm f/5.7, 22x, Bortle 6
2020-04-24: Widely separated with little difference in brightness. Both components appeared slightly yellowish. Standing close to 6 Boo, which also shines in a slight yellow.

SHJ 191 (**)
Name: SHJ191
Type: **
Constellation: Boo
Coordinates: 14h59m34.58s / +53°51'36.70"

Components:
m1 m2 ρ θ Year
6m9 7m6 40.4" 342° 2018
Robert Zebahl
B 8x40
2020-04-05: Easily separable with clearly visible difference in brightness. Nice separation of the components. Colors not perceptible.
55mm f/9.1, 27x
2020-04-05: Widely separated pair with rather small difference in brightness. Primary component: creamy white, companion: slightly orange.
70mm f/5.7, 22x, Bortle 6
2020-04-24: Widely separated with a moderate difference in brightness. Striking. The brighter component appeared yellowish-orange, the fainter one somehow darker and occasionally also cooler.

STF 1772 (**)
Name: STF1772, 1 Boo
Type: **
Constellation: Boo
Coordinates: 13h40m40.50s / +19°57'20.40"

Components:
m1 m2 ρ θ Year
AB 5m8 9m6 4.4" 134° 2017
AC 5m8 12m2 87.5" 26° 2015
AD 5m8 7m4 208.4" 1° 2010
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
AD: 2020-04-24: Very widely split with clearly visible difference in brightness. The primary component appeared white-yellowish, the companion pale orange.

STF 1821 (**)
Name: STF1821, kappa Boo, 17 Boo, Asellus Tertius
Type: **
Constellation: Boo
Coordinates: 14h13m29.00s / +51°47'23.80"

Components:
m1 m2 ρ θ Year
AB 4m5 6m6 13.7" 236° 2017

../images/binary-star-orbits/STF1821-AB-orbit.jpg

Robert Zebahl
70mm f/5.7, 22x, Bortle 6
2020-04-24: Clearly separated with significant difference in brightness. The primary component showed a pale yellowish-orange color with a greyish companion. To the southeast there is the double star STFA 26.

STF 1834 (**)
Name: STF1834
Type: **
Constellation: Boo
Coordinates: 14h20m17.60s / +48°30'25.10"

Components:
m1 m2 ρ θ Year
8m1 8m3 1.6" 104° 2018

../images/binary-star-orbits/STF1834-orbit.jpg

Robert Zebahl
120mm f/5, 150x, Bortle 6, NELM 5m0+, SQM-L 19.4
At 108x elongated, at 150x barely split with similarly bright components.

STF 1835 & BU1111 (**)
Name: STF1835 & BU1111, WDS14234+0827
Type: **
Constellation: Boo
Coordinates: 14h23m22.74s / +08°26'47.90"

Components:
m1 m2 ρ θ Year
STF1835 A-BC 5m0 6m8 6.2" 196° 2018
BU1111 BC 7m4 7m7 0.3" 16° 2018

../images/binary-star-orbits/BU1111-BC-orbit.jpg

Robert Zebahl
102mm f/11, 62x
STF1835 (A-BC): At 28x barely split with visible difference in brightness. At 62x easy to separate. The colors seemed similar.

STF 1838 (**)
Name: STF1838
Type: **
Constellation: Boo
Coordinates: 14h24m05.76s / +11°14'49.10"

Components:
m1 m2 ρ θ Year
7m5 7m7 9.7" 335° 2017
Robert Zebahl
70mm f/5.7, 44x, Bortle 6
2020-04-24: At 22x small, fine and remarkable double star with small difference in brightness, at 44x with visible color difference: orange & white-bluish.

STF 1850 (**)
Name: STF1850
Type: **
Constellation: Boo
Coordinates: 14h28m33.29s / +28°17'25.90"

Components:
m1 m2 ρ θ Year
7m1 7m6 25.2" 263° 2018
Robert Zebahl
B 8x40
2020-04-05: Separated, but still quite close together with a moderate difference in brightness.
70mm f/5.7, 22x, Bortle 6
2020-04-24: Easily separated, medium bright with rather small difference in brightness and moderate distance. Fairly conspicuous. The components appeared white-yellowish and white-bluish. Beautiful double star.

STF 1864 (**)
Name: STF1864, pi 1 Boo
Type: **
Constellation: Boo
Coordinates: 14h40m43.56s / +16°25'05.90"

Components:
m1 m2 ρ θ Year
AB 4m9 5m8 5.4" 113° 2019
Robert Zebahl
70mm f/5.7, 31x, Bortle 6
2020-04-24: At 22x immediately visible as figure '8' with visible difference in brightness. Beside omicron Boo there are no other brighter stars in the nearer surroundings. At 31x cleanly split, but still close together with noticeable difference in brightness. Both components appear white. Beautiful sight. At 57x very nice with a slightly different color impression: white & dark yellow.

STF 1877 (**)
Name: STF1877, epsilon Boo, Izar
Type: **
Constellation: Boo
Coordinates: 14h44m59.14s / +27°04'29.90"

Components:
m1 m2 ρ θ Year
AB 2m6 4m8 2.8" 347° 2018
Robert Zebahl
55mm f/9.1, 125x
The fainter component was seen as permanent brightening on the first diffraction ring of the primary component.
60mm f/10, 192x, Bortle 6-, SQM-L 19.1
Easy to split, whereby the much fainter component lies on the first diffraction ring of the primary component. The primary component itself appeared slightly yellowish.

../sketches/2018-04-10_epsilon_boo.jpg

70mm f/5.7, 133x, Bortle 6, SQM-L 19.2
Easy to split, very unequal. A appeared in pale orange, B was visible as a very tiny, grey star on the first diffraction ring of component A.
120mm f/5, 192x, Bortle 4, SQM-L 21.3
At 85x the fainter component was easily visible but not separated. At 192x well split. The fainter component was almost on the first diffraction ring of the primary component. Quite big difference in brightness. I did not looked at the color of the components.

STF 1884 (**)
Name: STF1884
Type: **
Constellation: Boo
Coordinates: 14h48m23.37s / +24°22'01.00"

Components:
m1 m2 ρ θ Year
6m6 7m5 2.1" 58° 2019

../images/binary-star-orbits/STF1884-orbit.jpg

Robert Zebahl
102mm f/11, 86x
At 86x pretty tight and unequal. At 160x clearly split. A: white, B: slightly orange.

STF 1886 (**)
Name: STF1886
Type: **
Constellation: Boo
Coordinates: 14h51m02.31s / +09°43'25.20"

Components:
m1 m2 ρ θ Year
AB 7m6 9m7 7.9" 224° 2018
Robert Zebahl
102mm f/11, 28x
At 28x, the B component appeared rather faint and pretty close to the primary component. At 62x both components were clearly visible and unequal. A: slightly orange, B: greyish.

STF 1888 & ARN11 (**)
Name: STF1888 & ARN11, xi Boo, 37 Boo
Type: **
Constellation: Boo
Coordinates: 14h51m23.38s / +19°06'01.70"

Components:
m1 m2 ρ θ Year
STF1888 AB 4m8 7m0 5.3" 300° 2018
STF1888 AC 4m8 13m8 71.3" 340° 2015
STF1888 AD 4m8 11m7 160.8" 286° 2015
ARN11 AE 4m8 8m7 271.5" 98° 2015
ARN11 AF 4m8 9m2 337.5" 37° 2015
STF1888 BC 7m0 13m8 63.9" 340° 2001
STF1888 BE 7m0 8m7 273.5" 102° 2009

../images/binary-star-orbits/STF1888-AB-orbit.jpg

Robert Zebahl
70mm f/5.7, 44x, Bortle 6
AB: 2020-04-24: Beautifully separated with quite a large difference in brightness in a lovely star field. The primary component shines yellowish with a faint companion.

STF 1890 (**)
Name: STF1890, 39 Boo
Type: **
Constellation: Boo
Coordinates: 14h49m41.37s / +48°43'15.60"

Components:
m1 m2 ρ θ Year
6m3 6m7 2.5" 46° 2019

../images/binary-star-orbits/STF1890-orbit.jpg

Robert Zebahl
70mm f/5.7, 100x, Bortle 6, NELM 5m0+, SQM-L 19.4
2020-04-18: At 57x very finely separated with extremely tightly spaced components that appeared equally bright. At 100x a very nice pair with little difference in brightness. Fantastic sight! The color of the components was slightly different: creamy-white & a touch of yellow-orange.
70mm f/5.7, 67x, Bortle 6, SQM-L 19.2
2020-04-01: At 44x elongated, partly notched. At 67x split, but very tight. A difference in brightness was not seen. At 133x clearly separated with little difference in brightness. A appeared pale yellow, B rather warm-white.

STF 1910 (**)
Name: STF1910
Type: **
Constellation: Boo
Coordinates: 15h07m32.95s / +09°13'33.80"

Components:
m1 m2 ρ θ Year
7m3 7m5 3.9" 211° 2019
Robert Zebahl
70mm f/5.7, 44x, Bortle 6
2020-04-24: At 31x clearly visible as figure '8' and almost separated with similarly bright components. At 44x still very tight, but separated pair. Overall rather faint with little difference in brightness. The primary component appeared slightly yellowish-orange.

STFA 26 (**)
Name: STFA26, iota Boo, 21 Boo
Type: **
Constellation: Boo
Coordinates: 14h16m10.07s / +51°22'01.30"

Components:
m1 m2 ρ θ Year
AB 4m8 7m4 38.9" 33° 2017
Robert Zebahl
B 8x40
2020-04-05: Even with tripod the faint companion was not visible.
70mm f/5.7, 22x, Bortle 6
2020-04-24: Similar view to the northwest standing kappa Boo. Nicely separated with larger distance and fainter companion. The primary component appeared rather white.

STFA 27 (**)
Name: STFA27, delta Boo, 49 Boo
Type: **
Constellation: Boo
Coordinates: 15h15m30.16s / +33°18'53.40"

Components:
m1 m2 ρ θ Year
AB 3m6 7m9 105.0" 78° 2017
Robert Zebahl
70mm f/5.7, 22x, Bortle 6
2020-04-24: Widely separated pair with large difference in brightness. Less striking. The bright primary component shines in a bright yellow.

STT 298 (**)
Name: STT298
Type: **
Constellation: Boo
Coordinates: 15h36m02.22s / +39°48'08.90"

Components:
m1 m2 ρ θ Year
AB 7m2 8m4 1.3" 187° 2017
AB-C 6m9 7m8 120.4" 328° 2017
AB-D 6m9 13m9 167.4" 224° 2002
AB-E 6m9 12m1 456.0" 335° 2002

../images/binary-star-orbits/STT298-AB-orbit.jpg

Robert Zebahl
102mm f/11, 28x
AB-C: Wide, moderately unequal pair. Little difference in color: Primary components appeared a bit more orange colored.
120mm f/5, 23x, Bortle 6, NELM 5m0+, SQM-L 19.4
AB-C: Easy to split with large angular distance and noticeable difference in brightness.