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Comet

Lemmon

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C/2017 E5 (Lemmon)

Lemmon is a comet in the Comet orbit class. Its orbit takes it from 1.78 AU to 816.18 AU from the Sun; one orbit takes 8,271.1 years. Orbit from the JPL solution of 20 June 2022.

Where is it now

Distance from Sun
24.897 AU
True anomaly
149.41°
Distance from Earth
24.753 AU
As of
25 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 Lemmon — 24.897 AU from the Sun Lemmon
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Lemmon is 24.753 AU from Earth today (3.4 light-hours).

In the sky

Right ascension
09h 30m 49s
Declination
+77° 18′ 27″
Constellation
Draco
Distance from Earth
24.75 AU
Elongation from the Sun
97.23° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

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
408.982 AU
Eccentricity
0.9956
Inclination
122.64°
Orbital period
8,271.1 years
Perihelion
1.783 AU
Aphelion
816.181 AU
Longitude of ascending node
206.19°
Argument of periapsis
306.77°
Epoch · J2000
2457765.5
Orbit class · COM
Comet
Earth MOID · 396.3 LD
1.0184 AU
Tisserand (Jupiter)
-0.879

Orbit quality

Observations used
112
Data arc
645 days
First observed
22 August 2015
Last observed
28 May 2017
Residual RMS
0.64 ″
Solution · Otto Matic
20 June 2022

Visual & observation

Absolute magnitude (H)
15.9
Total magnitude M₁ · K₁ 4.5
15.9

Discovery & classification

Also known as 2017 E5

Named

Sources