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Trans-Neptunian object

2015 RO278

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(2015 RO278)

Where is it now

Distance from Sun
37.082 AU
True anomaly
48.39°
Distance from Earth
36.096 AU
As of
22 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 — 0.995 AU from the Sun Earth 2015 RO278 — 37.082 AU from the Sun 2015 RO278
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2015 RO278 is 36.096 AU from Earth today (5.0 light-hours).

In the sky

Right ascension
01h 42m 50s
Declination
+03° 18′ 21″
Constellation
Pisces
Distance from Earth
36.1 AU
Elongation from the Sun
171.66° — 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
45.549 AU
Eccentricity
0.2386
Inclination
25.36°
Orbital period
307.4 years
Perihelion
34.682 AU
Aphelion
56.416 AU
Longitude of ascending node
190.88°
Argument of periapsis
147.35°
Epoch · J2000
2461200.5
Orbit class · TNO
Trans-Neptunian object
Earth MOID · 13,115.4 LD
33.7008 AU
Tisserand (Jupiter)
5.307

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
34
Data arc
4.36 years
First observed
23 June 2015
Last observed
1 November 2019
Residual RMS
0.17 ″
Solution · Otto Matic
15 September 2025

Visual & observation

Absolute magnitude (H)
8.87

Discovery & classification

TNO

Sources