- Double Stars (UMa) -

And (31) Cep (13) CVn (2) Her (12) Ori (8) Tri (5)
Aql (9) Cet (1) Cyg (19) Leo (11) Peg (16) UMa (9)
Ari (8) CMa (1) Del (2) LMi (4) Per (18) UMi (1)
Aur (25) Cnc (4) Dra (8) Lyn (11) Psc (7) Vir (6)
Boo (8) Com (1) Equ (5) Lyr (8) Ser (3)
Cam (5) CrB (4) Eri (1) Mon (1) Sex (1)
Cas (17) Crv (1) Gem (18) Oph (1) Tau (11)

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.

STF1258 (**)

Name: STF1258
Type: **
Constellation: UMa
Coordinates: 08h43m25.41s / +48°51'41.90"

Components:
m1 m2 ρ θ Year
7.7 7.9 10.0" 330° 2017
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-blueish, with the color changing from one component to another. A very strange effect, which I observed several times.

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.

STF1306 (**)

Name: STF1306, sigma 2 UMa, 13 UMa
Type: **
Constellation: UMa
Coordinates: 09h10m23.53s / +67°08'03.30"

Components:
m1 m2 ρ θ Year
AB 4.9 8.8 4.3" 348° 2016
AC 4.9 10.3 197.8" 148° 2003
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.

STF1315 (**)

Name: STF1315
Type: **
Constellation: UMa
Coordinates: 09h12m45.94s / +61°40'32.70"

Components:
m1 m2 ρ θ Year
7.3 7.7 24.9" 27° 2017
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.

STF1318 (**)

Name: STF1318
Type: **
Constellation: UMa
Coordinates: 09h13m38.79s / +46°59'25.30"

Components:
m1 m2 ρ θ Year
7.8 9.5 2.6" 228° 2017
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.

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.

STF1744 (**)

Name: STF1744, zeta UMa
Type: **
Constellation: UMa
Coordinates: 13h23m55.42s / +54°55'31.50"

Components:
m1 m2 ρ θ Year
79 UMa, zeta UMa, Mizar AB 2.2 3.9 14.4" 153° 2017
Mizar + Alcor AC 2.2 4.0 707.7" 72° 2017
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).

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