- Sketches (Deepsky) (Boo) -

And (1) Cas (5) Cyg (7) Her (4) Lyr (5) Sex (1)
Aur (4) Cnc (4) Dra (5) Leo (12) Ori (2) Tau (1)
Boo (2) Com (2) Eri (1) LMi (3) Per (6) Tri (1)
Cam (4) CVn (7) Gem (8) Lyn (9) Psc (1) UMa (10)

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" 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.

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.