Double Bear-rel

by Tom Campbell


April 1, 2003

ObserverTom Campbell
LocationIola, Kansas (Long: 95°24'W Lat: 37°55'N)
EquipmentDiscovery DHQ 8" dobsonian
Eyepieces1.25" Plössls - 25mm (49x), 15mm (81x), 10mm (122x), 6.5mm (188x), 4mm (305x)
Time8:25pm - 10:00pm CST (02:25-04:00 UT)
TransparencyMostly Clear (7/10)
SeeingMostly Stable (7/10)
WeatherTemperatures in the lower 60s. There was a moderate breeze.

Observing Summary
URSA MAJORMizar, Nu, Xi, Sigma-2, 21, 23, 57, Struve 1321, Struve 1695

Between cloudy weather and some prior commitments, I was beginning to think that I'd have to forego any observing opportunities during this New Moon period. However, the clouds stayed away tonight, and as luck would have it, my schedule was free.

Some Herschel-400 galaxies were at the top of my observing list, but the wind tonight was just strong enough to hamper my efforts at finding them. The jiggling eyepiece made even the brightest galaxies appear as dim, featureless blobs.

Double stars would be ideal for tonight, but I had just completed the Astronomical League's Double Star list. I've been a member of the Yahoo double star group called S33 for some time, but had yet to try out one of their monthly observing lists, so now seemed like the perfect time. This month, the doubles were in Ursa Major, an easy target for my backyard. I grabbed their latest list, my star charts, and headed outside.

NuUrsa MajorDouble Star8:25pm CST
Struve 1524RA: 11h 18m 30sDec: +33° 06'Mag: 3.5, 10.1

The primary is bright yellow and is visible to the naked eye. The bluish companion is a really faint pinprick right next to the main star. I could just barely detect it at 122x.

XiUrsa MajorDouble Star8:30pm CST
53RA: 11h 18m 11sDec: +31° 32'Mag: 3.9, 4.4

Both stars in this pair are about equal brightness, and both are yellow-white. At 305x, I could barely split them.

23Ursa MajorDouble Star8:40pm CST
Struve 1351RA: 09h 31m 32sDec: +63° 04'Mag: 3.7, 9.2

This is a fairly wide double, easily split at 49x. The main star is visible to the naked eye, and appears white. The companion is faint and the color is difficult to discern.

Struve 1695Ursa MajorDouble Star8:45pm CST
RA: 12h 56m 18sDec: +54° 06'Mag: 5.8, 10.4

This pair is nicely split at 122x. The brighter star is blue-white and the secondary is fainter and orange-white.

ZetaUrsa MajorDouble Star8:55pm CST
MizarRA: 13h 23m 56sDec: +54° 56'Mag: 2.3, 4.0

This is always fun to look at. At 49x, Alcor easily fits in the same field of view. Both stars are easily split, and both appear brilliant white or blue-white.

Sigma-2Ursa MajorDouble Star9:05pm CST
Struve 1306RA: 09h 10m 23sDec: +67° 08'Mag: 4.9, 7.9

The primary star is bright white and the much fainter companion is orange-red. The best view is at 305x.

21Ursa MajorDouble Star9:45pm CST
Struve 1346RA: 09h 25m 36sDec: +54° 01'Mag: 7.8, 8.8

This pair is easily split at 122x. The primary is blue-white and the slightly fainter secondary is pale blue.

Struve 1321Ursa MajorDouble Star9:50pm CST
RA: 09h 14m 24sDec: +52° 41'Mag: 7.6, 7.7

This is a wide pair of almost identical stars. It is easily split at 49x. Both stars appear pale orange.

57Ursa MajorDouble Star9:55pm CST
Struve 1543RA: 11h 29m 04sDec: +39° 20'Mag: 5.3, 11.6

The primary is just barely naked-eye from my backyard. At 122x, the faint companion shows up nicely. The primary star is blue-white, and the companion is white.

The wind was really starting to pick up now. I decided to call it a night. Right as I looked away from the eyepiece a final time, I saw a bright red and white meteor streak silently overhead. An excellent way to end an observing session.