2013 01 22 – Jupiter and Moon Appulse

Last night, we were treated to a very close appulse between the Moon and Jupiter – what a beautiful site! We’ll have to wait until the year 2026 for a closer pairing. The Moon was 78% illuminated at 10.34 days’ lunation and was just below 70 degrees in altitude at 2200 local time on January 21st (0400UT on the 22nd). Europa transited Jupiter during the session, although I was so busy with the low magnification sketching sessions that I missed it. Three other Galilean moons were aligned and plainly visible through the telescope: Ganymede, Io and Callisto (E-W).

While setting up the 102mm refractor between 1800-1830ST, it was easy to spot the Moon and Jupiter naked eye to the south. My first sketch of the event was at 1904ST (0104UT) and Jupiter was 1 degree away from the Moon. Please note that the Moon and star placements in the sketch are slightly larger than the eyepiece view. I only discovered my error when it came time to plot the stars furthest away from Jupiter and Moon. I ended up having to plot them appropriately outside of the field circle as a result. Nearly half hour later at 2017ST, there was a 0.73 degree separation.  I plotted the Moon and Jupiter’s positions and again found that I didn’t leave enough room in the field circle to include all of the stars that were in my field of view. Third time is a charm, though, and somehow I managed include the entire star field (with the exception of one star) within the circle.  By the time I completed the final sketch, the pair was its closest separation of 0.67 degree. Even though my magnitudes are a little off and I’m sure the placements could have been more accurate, the general feel of the eyepiece view is apparent.

Please click on the individual images for a closer view.




Eyepiece sketches created with black Strathmore Artagain paper, white Conté pastel pencil and color pencil, black color pencil.


~ by Erika Rix on January 22, 2013.

2 Responses to “2013 01 22 – Jupiter and Moon Appulse”

  1. Your observing report is completely amazing. Thanks for sharing.

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