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09/05/2017 – Ephemeris – Neptune’s at opposition from the Sun today

September 5, 2017 1 comment

Ephemeris for Tuesday, September 5th. The Sun will rise at 7:09. It’ll be up for 13 hours and 1 minute, setting at 8:11. The Moon, 1 day before full, will set at 7:22 tomorrow morning.

The sea green eighth planet from the Sun is named for the Roman god of the sea, Neptune. Today it is at opposition from the Sun, meaning it is opposite the Sun in the sky, rising at sunset. It resides at 30 times the Earth’s distance from the Sun. It is seen now against the stars of the constellation of Aquarius. While it is barely visible in binoculars the bright Moon will serve as a pointer to it tonight, but also make it hard to find. It will be three and a half moon widths left of the Moon* at 10 p.m. In telescopes it shows a tiny disk, so it’s not quite star-like. The large dark spot seen on Neptune in 1989 by Voyager 2 soon disappeared, however two years ago Neptune began to show activity again as seen from Earth and by the Hubble Space Telescope.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

* For the Eastern Daylight Time zone (0200 UT, 2017/09/06).  Add one Moon diameter for every hour prior to 0200 UT, subtract one for every hour after 0200 UT.

Addendum

Click on the charts to enlarge

The constellations around Neptune

The constellations around Neptune at 10 p.m. September 5, 2017. Created using Cartes du Ciel (Sky Charts).

Neptune finder chart

Finding Neptune tonight, September 5, 2017. Neptune moves slowly, so this finder chart, without the Moon, will work for a few months, Created using Cartes du Ciel (Sky Charts).

The constellations around Neptune

A 300 day track for Neptune with positions every 15 days starting September 5, 2017. Created using Cartes du Ciel (Sky Charts).

Neptune from Voyager 2

Neptune with the Great Dark Spot in 1979 as seen by Voyager 2. Credit NASA/JPL

Neptune from the Hubble Space Telescope

Neptune from the Hubble Space Telescope in 2016. Credit NASA/ESA.