Neptune
Neptune Sky Charts and Coordinates
This is a simplified sky chart, showing where Neptune is now with respect to the brightest stars and constellations.
More advanced sky charts are available on TheSkyLive for this object: 1) the Online Planetarium which is interactive and allows to select dates and additional objects to visualize; and 2) the Live Position and Data Tracker which provides the highest precision position data and features deep sky imagery from the Digitized Sky Survey.
Neptune Rise and Set Times
Today's Neptune rise, transit and set times from Greenwich, United Kingdom [change]. All times are relative to the local timezone Europe/London.
Neptune Ephemeris
The following table lists the ephemerides of Neptune computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Neptune in our Online Planetarium at the chosen date.
| Date | MagnitudeMag | Right AscensionR.A. | DeclinationDec. | Constellation |
|---|---|---|---|---|
| 2017 Sep 14 | 7.82 | 22h 56m 22s | -07° 47’ 29” | Aquarius |
| 2017 Sep 15 | 7.82 | 22h 56m 17s | -07° 48’ 06” | Aquarius |
| 2017 Sep 16 | 7.82 | 22h 56m 11s | -07° 48’ 42” | Aquarius |
| 2017 Sep 17 | 7.82 | 22h 56m 04s | -07° 49’ 20” | Aquarius |
| 2017 Sep 18 | 7.82 | 22h 55m 59s | -07° 49’ 58” | Aquarius |
| 2017 Sep 19 | 7.82 | 22h 55m 53s | -07° 50’ 34” | Aquarius |
| 2017 Sep 20 | 7.82 | 22h 55m 46s | -07° 51’ 11” | Aquarius |
| 2017 Sep 21 | 7.82 | 22h 55m 41s | -07° 51’ 47” | Aquarius |
| 2017 Sep 22 | 7.82 | 22h 55m 35s | -07° 52’ 23” | Aquarius |
| 2017 Sep 23 | 7.82 | 22h 55m 30s | -07° 52’ 59” | Aquarius |
| 2017 Sep 24 | 7.82 | 22h 55m 23s | -07° 53’ 34” | Aquarius |
| 2017 Sep 25 | 7.82 | 22h 55m 18s | -07° 54’ 08” | Aquarius |
| 2017 Sep 26 | 7.82 | 22h 55m 12s | -07° 54’ 43” | Aquarius |
| 2017 Sep 27 | 7.82 | 22h 55m 06s | -07° 55’ 18” | Aquarius |
Distance of Neptune from Earth
The following chart shows the distance of Neptune from Earth as a function of time. Distance data is measured in Astronomical Units and sampled with a 2 days interval.
The reported distances might be inaccurate around the times of closest approach for objects passing extremely close to Earth.
Light Curve of Neptune
The following chart is the predicted light curve (visual magnitude as a function of time) of Neptune, according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.
Neptune Physical Data
The following shows the known values of the most important physical parameters of Neptune. Source: JPL Small-Body Database
| Physical Parameter | Value | Relative to Earth |
|---|---|---|
| Diameter | 49244 km | 3.8647 |
| Mass | 102.41 x 1024 kg | 17.1478 |
| Density | 1.638 gr/cm3 | 0.2971 |
| Escape Velocity | 23.56 km/s | 2.1055 |
| Sideral Rotation | 16.1100 hours | 0.6731 |
| Absolute Magnitude | -6.87 | |
| Geometric Albedo | 0.41 | |