Neptune
Neptune is currently in the constellation of Aquarius. The current Right Ascension of Neptune is 23h 20m 01s and the Declination is -05° 28’ 08” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current magnitude of Neptune is 7.94 (JPL).
Summary of key facts about Neptune [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:
- Neptune is above the horizon from Greenwich, United Kingdom [change].
- It is visible looking in the South-South-East direction at an altitude of 32° above the horizon.
- Given its current magnitude, Neptune is visible with the help of a binocular with a 30-40mm aperture, easy with a small telescope.
- See also Neptune rise and set times.
- Go to interactive sky chart
If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.
Additional information about Neptune available on TheSkyLive:
Neptune Position and Finder Charts
Below we provide Neptune finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.
Higher precision deep sky finder chart, 60 arcmin wide, showing where Neptune is right now. Click on the image to see a more detailed fullscreen tracker view.
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 from Earth
The distance of Neptune from Earth is currently 4,575,683,890 kilometers, equivalent to 30.586558 Astronomical Units. Light takes 4 hours, 14 minutes and 22.8386 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 1900 and January 2100, the closest approach of Neptune to Earth happens on Tue Oct 29 2041 at a distance of 28.814172 Astronomical Units, or 4,310,538,781 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 7.94.
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, considering the effect of the atmospheric refraction. As the atmospheric 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 |
|---|---|---|---|---|---|
| 2021 Jan 14 | 23h 19m 17s | -05° 32’ 59” | 7.93 | 2.2” | Aquarius |
| 2021 Jan 15 | 23h 19m 22s | -05° 32’ 24” | 7.93 | 2.2” | Aquarius |
| 2021 Jan 16 | 23h 19m 27s | -05° 31’ 46” | 7.93 | 2.2” | Aquarius |
| 2021 Jan 17 | 23h 19m 32s | -05° 31’ 09” | 7.93 | 2.2” | Aquarius |
| 2021 Jan 18 | 23h 19m 39s | -05° 30’ 30” | 7.93 | 2.2” | Aquarius |
| 2021 Jan 19 | 23h 19m 45s | -05° 29’ 52” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 20 | 23h 19m 50s | -05° 29’ 12” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 21 | 23h 19m 56s | -05° 28’ 32” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 22 | 23h 20m 03s | -05° 27’ 51” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 23 | 23h 20m 09s | -05° 27’ 11” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 24 | 23h 20m 16s | -05° 26’ 29” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 25 | 23h 20m 22s | -05° 25’ 46” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 26 | 23h 20m 29s | -05° 25’ 05” | 7.94 | 2.2” | Aquarius |
| 2021 Jan 27 | 23h 20m 35s | -05° 24’ 20” | 7.94 | 2.2” | Aquarius |