Neptune
Neptune Position
Neptune is currently in the constellation of Aquarius. The current Right Ascension is 23h 15m 40s and the Declination is -05° 54’ 27”.
Simplified sky chart showing where Neptune is right now in the sky with respect to the brightest stars and constellations (see fuillscreen Online Planetarium)
Hihgher precision deep sky finder chart showing where Neptune is right now (view fullscreen)
Also check out Where is Neptune?, a page that provides all the information needed to find Neptune in the sky and additional links to sky charts.
Neptune Distance
The distance of Neptune from Earth is currently 4,333,513,993 kilometers, equivalent to 28.967752 Astronomical Units. Light takes 4 hours, 55.0467 seconds to travel from Neptune and arrive to us.
The following chart shows the distance of Neptune from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.
The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of Neptune from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest approach of Neptune to Earth
Between January 2013 and December 2049 the closest approach of Neptune to Earth happens on Tue Oct 29 2041 at a distance of 28.81417661 Astronomical Units, or 4,310,539,476 kilometers:
NOTE: values for the closest approach are computed with a sampling interval of 1 day.
Neptune brightness
The current visual magnitude of Neptune is 7.82.
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 rise and set times
Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London
Today's Neptune rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):
The rise and set times are defined as the time at which the upper limb of Neptune touches the horizon, consideting the effect of the atmospheric refraction. As the atmoshpere conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.
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 |
Neptune 15 Days 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 | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Apparent DiameterDiameter | Constellation |
|---|---|---|---|---|---|
| 2019 Aug 16 | 23h 16m 23s | -05° 49’ 35” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 17 | 23h 16m 18s | -05° 50’ 11” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 18 | 23h 16m 14s | -05° 50’ 47” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 19 | 23h 16m 08s | -05° 51’ 23” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 20 | 23h 16m 01s | -05° 52’ 00” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 21 | 23h 15m 56s | -05° 52’ 36” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 22 | 23h 15m 51s | -05° 53’ 13” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 23 | 23h 15m 46s | -05° 53’ 50” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 24 | 23h 15m 39s | -05° 54’ 28” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 25 | 23h 15m 33s | -05° 55’ 05” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 26 | 23h 15m 28s | -05° 55’ 44” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 27 | 23h 15m 21s | -05° 56’ 21” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 28 | 23h 15m 16s | -05° 57’ 01” | 7.82 | 2.3” | Aquarius |
| 2019 Aug 29 | 23h 15m 11s | -05° 57’ 38” | 7.82 | 2.3” | Aquarius |