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A slow binary in Gemini


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About this observation
Nick Hewitt
Time of observation
21/02/2019 - 18:50
38 Geminorum
Observing location
TMB 115mm f7 triplet
Canon 60Da
5 x 2 sec ISO 800

This slow binary has a 1898 year orbit but its motion can be detected by careful measure if your life is long enough! It has opened slightly from 6.7" in 1940 to 7.3" now, and its PA has changed from 154 degrees to about 142 in the same 80 years. Its components magnitudes are 4.7 and 7.7 so its could eb a vey good practice binary for embryonic binary enthusiasts.

North is up, west to the right. Larger apertures should split the stars very cleanly. My 115mm is too small and the focal length too short to do it justice. 

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