- Double Stars (UMa) -

And (13) Cep (9) Cyg (4) LMi (4) Per (3) UMi (1)
Aql (9) CMa (1) Del (2) Lyn (9) Psc (1) Vir (6)
Ari (5) Cnc (2) Dra (8) Lyr (5) Ser (1)
Aur (15) Com (1) Eri (1) Mon (1) Sex (1)
Boo (8) CrB (3) Gem (9) Oph (1) Tau (6)
Cam (2) Crv (1) Her (12) Ori (8) Tri (3)
Cas (11) CVn (2) Leo (11) Peg (4) UMa (4)

41 Lyn (**)

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

Components:
m1 m2 ρ θ Year
AB 5.5 7.8 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.

B 40mm, 8x, Bortle 7, NELM 5.0, SQM-L 19.2
Fairly well split with fainter component.

STF1275 (**)

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

Components:
m1 m2 ρ θ Year
AB 8.7 8.9 1.9" 198° 2015
70mm f/5.7, 100x
At 100x and 150x not permanently split. Components very close together.

STF1523 (**)

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 4.3 4.8 1.9" 166° 2017
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.

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 5.0+
2019-02-06: Well split with visible difference in brightness. The colors of both components appeared equal.

STF1579 (**)

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

Components:
m1 m2 ρ θ Year
AB-C 6.7 8.3 3.8" 40° 2017
AB-D 6.7 7.0 63.7" 113° 2017
55mm f/9.1, 83x, Bortle 6-, SQM-L 19.1
AB-C: Easy to split, but the faint C component only appeared as a tiny star.

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

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.