Comet 77P/Longmore
Comet 77P/Longmore is in the constellation of
Cetus,
at a distance of
Finder Charts
View interactive star map
High precision deep sky finder chart, 60 arcmin wide, showing where Comet 77P/Longmore is right now. Click on the image to see a more detailed fullscreen tracker view.
Also check out Where is Comet 77P/Longmore?, a page that provides all the information needed to find Comet 77P/Longmore in the sky and additional links to sky charts.
Celestial Coordinates
Apparent
J2000
Additional Information
The observed values of Magnitude, Coma Diameter and Tail Length are derived from the most recent observation recorded at the Comet Observers Database. The value of Predicted Magnitude comes from the JPL Horizons ephemerides service and, in the case of comets, might be inaccurate given the highly dynamic and unpredictable behavior of these objects. When available, please refer to the Observed Magnitude value and consider the Predicted Magnitude as a directional indication. We acknowledge with thanks the comet observations from the COBS Comet Observation Database contributed by observers worldwide and used in this table to report recent comet observations.
Rise and Set Times
Today's rise, transit and set times of Comet 77P/Longmore from Greenwich, UK (all times relative to the local timezone Europe/London):
- 77P/Longmore is below the horizon from Greenwich, UK.
- Given its current magnitude, 77P/Longmore is visible only through long exposure photography.
- Go to interactive sky chart
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Distance from Earth
The distance of Comet 77P/Longmore from Earth is currently
The following chart shows the distance of Comet 77P/Longmore from Earth as a function of time. In the chart the distance data is measured in Astronomical Units and sampled with an interval of 1 day.
The value of the reported distance might be somewhat inaccurate around the times of closest approach for objects passing extremely close to Earth. The value of the distance of 77P/Longmore from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest Approach
Between 1 January 2000 and 31 December 2099, the closest approach of Comet 77P/Longmore to Earth happens on Sun Apr 22 2063 at a distance of 1.005950 Astronomical Units, or 150,488,024 kilometers:
NOTE: values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart is the predicted light curve (visual magnitude as a function of time) of Comet 77P/Longmore, according to the most recent ephemerides data. Magnitude data is sampled with a 2 days interval and there might be inaccuracies for objects changing brightness very rapidly during the course of a few days. For comets there could be large discrepancies between the observed and predicted brightness because of their highly dynamic behaviour.
Orbital Elements
The following table lists the orbital elements of Comet 77P/Longmore at epoch 06 January 2014 00:00 UTC (JD: 2456664.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.35417428 |
| Orbit inclination | i | 24.34085664° |
| Perihelion distance | q | 2.33317808 AU 349,038,474 km |
| Aphelion distance | Q |
4.89223274 AU 731,867,603 km |
| Semi-major axis | a |
3.61270541 AU 540,453,038 km |
| Orbital period | period |
6.8668 years 2,508.1139 days |
| Date of perihelion transit | Tp | 2016-May-14 11:40:24 2,457,522.9864 JD |
| Next perihelion transit | 2023-Mar-27 14:24 2,460,031.1003 JD |
|
| Argument of perihelion | peri | 196.95308063911° |
| Longitude of the ascending node | node | 14.888791515158° |
| Mean anomaly | M | 236.77788340474° |
| Mean motion | n | 0.14353415°/day |
View Comet 77P/Longmore in the 3D Solar System Simulator
15 Days Ephemeris
The following table lists the ephemerides of Comet 77P/Longmore computed for the past and next 7 days, with a 24 hours interval. Apparent celestial coordinates are provided.
| Date | Right AscensionR.A. | DeclinationDec. | MagnitudeMag | Constellation |
|---|---|---|---|---|
| 2025 May 20 | 00h 35m 23s | -04° 29’ 50” | 21.98 | Cetus |
| 2025 May 21 | 00h 36m 03s | -04° 24’ 41” | 21.98 | Cetus |
| 2025 May 22 | 00h 36m 43s | -04° 19’ 35” | 21.98 | Cetus |
| 2025 May 23 | 00h 37m 23s | -04° 14’ 33” | 21.98 | Cetus |
| 2025 May 24 | 00h 38m 02s | -04° 09’ 34” | 21.98 | Cetus |
| 2025 May 25 | 00h 38m 41s | -04° 04’ 39” | 21.97 | Cetus |
| 2025 May 26 | 00h 39m 20s | -03° 59’ 46” | 21.97 | Cetus |
| 2025 May 27 | 00h 39m 58s | -03° 54’ 58” | 21.97 | Cetus |
| 2025 May 28 | 00h 40m 35s | -03° 50’ 12” | 21.97 | Cetus |
| 2025 May 29 | 00h 41m 12s | -03° 45’ 31” | 21.97 | Cetus |
| 2025 May 30 | 00h 41m 49s | -03° 40’ 53” | 21.96 | Cetus |
| 2025 May 31 | 00h 42m 25s | -03° 36’ 18” | 21.96 | Cetus |
| 2025 Jun 01 | 00h 43m 00s | -03° 31’ 46” | 21.96 | Cetus |
| 2025 Jun 02 | 00h 43m 36s | -03° 27’ 20” | 21.96 | Cetus |
Additional Resources on TheSkyLive
- Comet 77P/Longmore: Complete reference information on TheSkyLive.com.
- Where is Comet 77P/Longmore?: Key information on locating Comet 77P/Longmore in the sky.
- Distance from Earth: Find out how far Comet 77P/Longmore is from Earth right now.
- How Bright is Comet 77P/Longmore?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Comet 77P/Longmore's rise and set times from your location.
- Interactive Sky Map: planetarium-style interactive visualization of Comet 77P/Longmore's position in the sky.
- Live Position Tracker: high precision position tracker with deep space imagery.
- Ephemeris: 15 days Comet 77P/Longmore's computed ephemeris.
- Orbital elements: information about Comet 77P/Longmore orbital parameters.
- Orbit Visualization. 3d interactive visualization showing the orbit of Comet 77P/Longmore with respect to the major Solar System objects.