Little Bear Tracks

Observer: Tom Campbell
Location: Iola, Kansas (Long: 95°24'W Lat: 37°55'N)
Equipment: Discovery DHQ 8" dobsonian
Eyepieces: 1.25" Plössls - 25mm (49x), 15mm (81x), 10mm (122x), 6mm (203x)
Time: 10:00pm - 11:30pm CDT (03:00-04:30 UT)
Transparency: Clear (8/10)
Seeing: Stable (8/10)
Weather: Temperatures in the low 60s. There was a light breeze. Relative humidity was about 68%

Observing Summary:
URSA MINOR: Alpha, Pi-1, HJ-2682, Struve1798, Struve1840, Struve1841, Struve1905

I knew that the Moon would be rising within a few hours of sunset tonight, but the twilight sky was so beautiful, I just had to set up my telescope. Knowing the sky would never get truly dark tonight, I opted for some double stars. The "Spirit of 33" double star observers have picked Ursa Minor this month. This constellation is well-placed in my sky, so I picked some of the easier ones from their list.

Struve1905 | Ursa Minor | Double Star | 10:00pm CDT
| RA: 14h 56m 48s | Dec: +70° 50' | Mag: 8.3, 8.4

This double is fairly faint, but both stars are about equal brightness. The tight pair could be separated at 122x, but the view was better at 203x. Both stars appeared white.

Struve1798 | Ursa Minor | Double Star | 10:10pm CDT
| RA: 13h 55m 00s | Dec: +78° 24' | Mag: 7.5, 9.7

This double was easily split at 49x, but the best view was at 122x. The bluish secondary is a couple of magnitudes fainter than the yellow-white primary.

Pi-1 | Ursa Minor | Double Star | 10:20pm CDT
Struve1972 | RA: 15h 29m 12s | Dec: +80° 27' | Mag: 6.6, 7.3

This nice-looking double was fairly wide, easily split at 49x. I preferred the view at 81x, however, due to better color contrast. The brighter star is white, and the fainter companion has a tinge of yellow.

Alpha | Ursa Minor | Double Star | 10:35pm CDT
Polaris | RA: 02h 31m 49s | Dec: +89° 16' | Mag: 2.1, 9.1

I always like looking at this double. Although I could easily find the faint companion at 49x, the best view was at 81x. At this magnification, the primary is yellow-shite and the companion is pale blue. It reminded me of what the Earth and Sun might look like from perhaps a moon of Saturn.

HJ2682 | Ursa Minor | Multiple Star | 10:40pm CDT
| RA: 13h 40m 42s | Dec: +76° 51' | Mag: 6.7, 9.0, 9.7

This was a triple star system, easily split at 49x. Increasing the magnification to 81x revealed some subtle colors. The brightest component was pale yellow-white, but the other two stars were a bit too faint to be able to detect colors. The faintest component is about halfway between and off to one side of the brighter two components, forming a triangle.

Struve1840 | Ursa Minor | Double Star | 11:10pm CDT
| RA: 14h 19m 54s | Dec: +67° 47' | Mag: 7.0, 10.4

The best view of this double was at 81x. The primary was white or blue-white, but I was unable to determine a color for the much fainter companion.

Struve1841 | Ursa Minor | Double Star | 11:15pm CDT
| RA: 14h 21m 06s | Dec: +67° 48' | Mag: 7.1, 10.7

The brightest component of this double forms an almost identical wide optical binary with the brighter star in Struve1840. In fact, both pairs looked very similar, except Struve1841 appeared to have a little different position angle, the secondary star was a little fainter, and it was a little more separated from the primary.

The nearly full Moon was peeking up over the eastern treetops, marking an end to the night's observing. Too bad, because it was a beautiful night. The temperatures stayed fairly constant tonight, allowing the mirror to stay within a half degree of the outside air for most of the evening.