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public  Añasco, Puerto Rico Añasco, Puerto Rico  ⓘ
TimezoneAmerica/Puerto_Rico
Sunrise: 5:59 
Transit: 12:33 
Sunset: 19:07
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Comets » 

Comet 77P/Longmore

Above the horizon.  Rise: 0:28 | Tran: 6:24 | Set: 12:20
Alt: 23.39°   Az: 260.03°   Direction: West

Comet 77P/Longmore is in the constellation of Cetus, at a distance of 646,515,044.0 kilometers from Earth. The current Right Ascension is 00h 58m 15s and the Declination is -01° 30’ 43” (apparent coordinates). The estimated magnitude of comet 77P/Longmore, computed using JPL Horizons's data, is 21.83.

Finder Charts

The sky charts below show, at different resolutions, the position of comet 77P/Longmore in the sky. Click on each chart to access the interactive star map tool.

Star map showing the position of comet 77P/Longmore in the constellation of Cetus on F, d Y. Field of view: 50x30 degrees. View interactive star map.
Star map showing the position of comet 77P/Longmore in the constellation of Cetus on F, d Y. Field of view: 15x9 degrees. View in interactive star map.

The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet 77P/Longmore against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.

77P/Longmore
RA: 00h 56m 56s
Dec: -01° 38’ 58”
Simplified high-resolution deep sky chart showing the current position of comet 77P/Longmore. Field of view: 60 x 40 arcminutes. Go to the dedicated page

Equatorial Coordinates

Apparent

00h 58m 15s
-01° 30’ 43”
04h 18m 54s
05h 17m 09s

J2000

00h 56m 56s
-01° 38’ 58”

Additional Information

Cetus
n/a
n/a
n/a
n/a
21.83

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

The following table lists today's rise, transit and set times of comet 77P/Longmore from Añasco, Puerto Rico (all times relative to the local timezone America/Puerto_Rico):

Azimuth: 91.5°
Max altitude: 70.2°
Azimuth: 268.5°

If you need to access this information frequently for your observations, you can create a simple customized Quick Access page, so that you can easily bookmark it in your browser favorites or add a shortcut to your mobile phones' home screen.

Distance from Earth

The distance of comet 77P/Longmore from Earth is currently 646,515,044.0 kilometers, equivalent to 4.3216861375 Astronomical Units. Light takes 35m 56.542s to travel from comet 77P/Longmore and arrive to us.

646,515,044.0
4.3216861375
35m 56.542s

The following graph shows the distance of comet 77P/Longmore from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.

Chart of the distance of comet 77P/Longmore from Earth in Astronomical Units (au)
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).

The value of the distance of 77P/Longmore from Earth is also available as a real time updated value in the live position tracker.

Closest Approach to Earth

In the period between January 1, 2000 and December 31, 2099, the closest approach of comet 77P/Longmore to Earth will happen on Sunday 22 April 2063 at a distance of 1.005950 Astronomical Units, or 150,488,024 kilometers:

Sunday 22 April 2063
150,488,024
1.005950

Note: the values for the closest approach are computed with a sampling interval of 1 day.

Light Curve

The following chart shows the light curve of comet 77P/Longmore, i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.

Chart of the magnitude of comet 77P/Longmore as a function of time

Orbital Elements

The following table lists the orbital elements of comet 77P/Longmore at epoch January, 06 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 May 14, 2016
2,457,522.9864 JD
Next perihelion transit March 27, 2023
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

Orbit Visualization

The following chart is a 3D animated visualization of the orbit of comet 77P/Longmore relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.

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
Jun 29 2025 00h 56m 16s -01° 48’ 19” 21.87 Cetus
Jun 30 2025 00h 56m 34s -01° 45’ 46” 21.86 Cetus
Jul 01 2025 00h 56m 52s -01° 43’ 17” 21.86 Cetus
Jul 02 2025 00h 57m 08s -01° 40’ 52” 21.85 Cetus
Jul 03 2025 00h 57m 24s -01° 38’ 32” 21.85 Cetus
Jul 04 2025 00h 57m 39s -01° 36’ 17” 21.85 Cetus
Jul 05 2025 00h 57m 54s -01° 34’ 06” 21.84 Cetus
Jul 06 2025 00h 58m 07s -01° 31’ 59” 21.84 Cetus
Jul 07 2025 00h 58m 20s -01° 29’ 56” 21.83 Cetus
Jul 08 2025 00h 58m 33s -01° 27’ 57” 21.83 Cetus
Jul 09 2025 00h 58m 44s -01° 26’ 03” 21.83 Cetus
Jul 10 2025 00h 58m 55s -01° 24’ 13” 21.82 Cetus
Jul 11 2025 00h 59m 05s -01° 22’ 28” 21.82 Cetus
Jul 12 2025 00h 59m 14s -01° 20’ 47” 21.81 Cetus

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