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Old 17-08-2009, 10:44 AM
Dennis
Dazzled by the Cosmos.

Dennis is offline
 
Join Date: May 2005
Location: Brisbane
Posts: 11,828
Nereid, moon of Neptune from Brisbane 15th August

Hello,

Here is my second attempt at recording Nereid, the outermost known moon of Neptune from its discovery in 1949 (by G. Kuiper) until 2002. The mean radius of Nereid is 170km and it has a magnitude of 18.72. The orbital period of Nereid is listed as 360.13619 days and its highly eccentric orbit helped keep the much brighter Neptune (7.83m) outside the field of view.

Using the NASA (JPL) Horizons system, I generated an ephemeris for the 15th August 2009 at 1 hour intervals and then slewed the ‘scope to the coordinates generated by Horizons.

The parent planet Neptune (diameter 49,528.0 km) lies some 2.796 billion miles from the Sun and has a rather chilly surface temperature of -209°C.

The attached image shows Nereid in the bottom left hand corner with an inverted inset to better show the motion trail over the 7 x 20 minute exposures. I have also included an inverted image and animation revealing Nereid’s movement over some 140 minutes.

Cheers

Dennis
Attached Thumbnails
Click for full-size image (Nereid Frame text.jpg)
45.6 KB92 views
Click for full-size image (Nereid inverted.jpg)
47.3 KB68 views
Click for full-size image (Nereid-Layers-Flip-Invert-Animation.gif)
187.3 KB85 views
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