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Trans-Neptunian object

2013 RU157

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(2013 RU157)

Where is it now

Distance from Sun
44.187 AU
True anomaly
253.95°
Distance from Earth
43.239 AU
As of
19 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Sun Earth — 0.996 AU from the Sun Earth 2013 RU157 — 44.187 AU from the Sun 2013 RU157
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2013 RU157 is 43.239 AU from Earth today (6.0 light-hours).

In the sky

Right ascension
01h 48m 08s
Declination
-07° 47′ 10″
Constellation
Cetus
Distance from Earth
43.24 AU
Elongation from the Sun
161.64° — near opposition — up most of the night

Visible from both hemispheres.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
43.411 AU
Eccentricity
0.1846
Inclination
33.07°
Orbital period
286 years
Perihelion
35.398 AU
Aphelion
51.423 AU
Longitude of ascending node
173.75°
Argument of periapsis
319.01°
Epoch · J2000
2461200.5
Orbit class · TNO
Trans-Neptunian object
Earth MOID · 13,417.4 LD
34.4767 AU
Tisserand (Jupiter)
4.878

Orbit quality

Orbit reasonably well determined (uncertainty code 5).

Observations used
21
Data arc
4.04 years
First observed
11 September 2013
Last observed
24 September 2017
Residual RMS
0.19 ″
Solution · Otto Matic
14 September 2021

Visual & observation

Absolute magnitude (H)
6.66

Discovery & classification

TNO

Sources