Double Stars - Ursa Major
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Note:
All images are at 1:1 scale taken with the same equipment (120mm refractor, 1000mm FL, Canon 450D DSLR) and same magnification unless stated. The Canon 450D gives equivilent to a 12mm EP, giving a mangnification factor of approximatly 80x. This means that the split between all stars can be compared against each other. Exposure times and ISO levels are adjusted to give best image of both components but on average they are 4 seconds at ISO 400
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22:46 UTC 06-02-2013Zeta UMA (Mizar)
A little confusing information with this double as the split is more commonly of Mizar and Alcor which has a split of around 11.5' (arc minutes), but Mizar has its own double. This image is of Mizar Aa and Mizar Ab, with a 14.5" (arc second) separation, it is an easy split. Magnitudes of 2.4 and 4.0 make this a bright double for imaging.
Trawling through the internet, there seems to be a lot of sites that indicate this is Mizar and Alcor, which caused me a lot of confusion. Details: Constellation: Ursa Major RA: 13h 23' 55.4" Dec: +54° 55' 31.5" PA: 152º Separation: 14.4"
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23:01 UTC 06-02-2013
STF 1520
Similar magnitudes of 6.6 and 7.9 with almost 13" separation made this an easy target and a nice easy split.
Details: Constellation: Ursa Major RA: 11h 16m 3.9s Dec: +52° 46' 35.8" PA: 344º Separation: 12.7"
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23:05 UTC 06-02-2013
STF 1415
Another easy pair, magnitudes of 6.7 and 7.3 with a nice wide 17" separation.
Details: Constellation: Ursa Major RA: 10h 17m 50.5s Dec: +71° 03' 38.0" PA: 167º Separation: 16.7"
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23:10 UTC 06-02-2013STF 1544
Magnitudes of 7.2 and 8.2 with almost 13" separation, similar to STF 1520, but slightly dimmer, just as easy to split. Details: Constellation: Ursa Major RA: 11h 31m 18.6s Dec: +59° 42' 3.3" PA: 90º Separation: 12.4"
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23:16 UTC 06-02-2013
STF 1427
Magnitudes of 7.5 and 8.0 with a 9" separation, nice and easy but appeared to be strangely dim, of course when I looked outside, I found I was looking through the clouds, but I did get them. Details: Constellation: Ursa Major RA: 10h 22m 0.0s Dec: +43° 54' 11.5" PA: 214° Separation: 9.4"