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Centaur

540205

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540205 (2017 RS17)

Where is it now

Distance from Sun
8.885 AU
True anomaly
187.38°
Distance from Earth
9.227 AU
As of
11 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.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth 540205 — 8.885 AU from the Sun 540205
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 540205 is 9.227 AU from Earth today (1.3 light-hours).

In the sky

Right ascension
17h 28m 37s
Declination
+09° 47′ 44″
Constellation
Ophiuchus
Distance from Earth
9.23 AU
Elongation from the Sun
66.56° — well clear of the Sun

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
6.176 AU
Eccentricity
0.4484
Inclination
42.71°
Orbital period
15.35 years
Perihelion
3.406 AU
Aphelion
8.945 AU
Longitude of ascending node
135.69°
Argument of periapsis
296.06°
Epoch · J2000
2461200.5
Orbit class · CEN
Centaur
Earth MOID · 1,028.9 LD
2.6437 AU
Tisserand (Jupiter)
2.274

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
99
Data arc
16.11 years
First observed
25 December 2003
Last observed
2 February 2020
Residual RMS
0.46 ″
Solution · Otto Matic
14 April 2021

Visual & observation

Absolute magnitude (H)
14.56

Discovery & classification

Discovered by
Pan-STARRS 1
Discovery date
9 August 2016
Discovery site
Haleakala

Also known as 2017 RS17

Centaur

Close approaches 5 on record

When (UTC) Body Distance Lunar distances Relative speed
2050-06-12 22:22:00 Juptr 1.3059 AU 508.2 LD 10.7 km/s
2092-08-28 23:40:00 Juptr 0.7511 AU 292.3 LD 10.2 km/s
2157-12-25 08:49:00 Juptr 1.394 AU 542.5 LD 12.5 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources