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Comet

Leonard

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C/2017 W2 (Leonard)

Leonard is a comet in the Halley-type comet orbit class. Its orbit takes it from 3.96 AU to 23.45 AU from the Sun; one orbit takes 50.74 years. Orbit from the JPL solution of 15 April 2021.

Where is it now

Distance from Sun
15.953 AU
True anomaly
144.01°
Distance from Earth
15.746 AU
As of
24 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 — 0.994 AU from the Sun Earth Leonard — 15.953 AU from the Sun Leonard
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Leonard is 15.746 AU from Earth today (2.2 light-hours).

In the sky

Right ascension
22h 56m 32s
Declination
-59° 04′ 36″
Constellation
Tucana
Distance from Earth
15.75 AU
Elongation from the Sun
100.02° — well clear of the Sun

Favours the southern hemisphere; low or below the horizon from far north.

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
13.705 AU
Eccentricity
0.7113
Inclination
98.18°
Orbital period
50.74 years
Perihelion
3.957 AU
Aphelion
23.453 AU
Longitude of ascending node
312.81°
Argument of periapsis
169.16°
Epoch · J2000
2458113.5
Orbit class · HTC
Halley-type comet
Earth MOID · 1,161.6 LD
2.9849 AU
Tisserand (Jupiter)
0.055

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
169
Data arc
384 days
First observed
23 April 2017
Last observed
12 May 2018
Residual RMS
0.48 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
10.9
Total magnitude M₁ · K₁ 10
10.9

Discovery & classification

Also known as 2017 W2

Named

Sources