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Comet 77P/Longmore

Comet 77P/Longmore is currently in the constellation of Perseus. The current Right Ascension of Comet 77P/Longmore is 02h 51m 35s and the Declination is +38° 26’ 07” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet 77P/Longmore is 21.60 (JPL).

Summary of key facts about Comet 77P/Longmore [tip: you can also create a Quick Access page for this data if you access it frequently and would like to have a simpler view]:

02h 51m 35s
+38° 26’ 07”
Perseus
21.60
  • 77P/Longmore is above the horizon from Greenwich, United Kingdom [change].
  • It is visible looking in the North-North-West direction at an altitude of 2° above the horizon.
  • Given its current magnitude, 77P/Longmore is visible only through long exposure photography.
  • See also 77P/Longmore rise and set times.
  • Go to interactive sky chart

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.

Additional information about Comet 77P/Longmore available on TheSkyLive:

Available Resources

Comet 77P/Longmore Position and Finder Charts

Below we provide Comet 77P/Longmore finder charts showing where the object is right now in the sky with respect to the brightest stars. The first finder chart has a field of view of 50 degrees, while the second one has a field of view of 10 degrees. Click on each finder chart to access a full screen interactive Online Planetarium.

Map showing Comet 77P/Longmore in Perseus on January, 25 2021
Field of view: 50x30 degrees
View fullscreen
Map showing Comet 77P/Longmore in Perseus on January, 25 2021
Field of view: 10x6 degrees
View fullscreen
 = visible to the naked eye
 = binocular, brighter than 10th magnitude
= current altitude ≥ 30°   = current altitude < 30°   = below the horizon
Location: Greenwich, United Kingdom [change]

Higher 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.

77P/Longmore
RA: 02h 51m 35s
Dec: +38° 26’ 07”
Deep sky finder chart for Comet 77P/Longmore
Field of view: 60x40 arcmins
View fullscreen

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.

Comet 77P/Longmore Distance from Earth

The distance of Comet 77P/Longmore from Earth is currently 608,217,423 kilometers, equivalent to 4.065682 Astronomical Units. Light takes 33 minutes and 48.7949 seconds to travel from Comet 77P/Longmore and arrive to us.

608,217,423
4.065682
33 minutes and 48.7949 seconds

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.

Distance of Comet 77P/Longmore from Earth between January 2013 and December 2100

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 of Comet 77P/Longmore to Earth

Between January 2013 and December 2100, the closest approach of Comet 77P/Longmore to Earth happens on Sun Apr 22 2063 at a distance of 1.005966 Astronomical Units, or 150,490,445 kilometers:

Sun Apr 22 2063
150,490,445
1.005966

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

Comet 77P/Longmore brightness

The current visual magnitude of Comet 77P/Longmore is 21.60.

21.60
-
-

The observed magnitude and coma diameter values are derived from the Comet Observers Database by averaging the values reported in recent observations (more recent than 4 days), when available. The Estimated Magnitude comes from the JPL Horizons ephemerides service and might be inaccurate given the highly dynamic and unpredictable behavior of comets. When available, please refer to the Observed Magnitude value and consider the Estimated 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.

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.

Predicted magnitude of Comet 77P/Longmore between January 2013 and December 2100

Comet 77P/Longmore rise and set times

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's Comet 77P/Longmore rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 51.6°
Max altitude: 76.9°
Azimuth: 308.4°

The rise and set times are defined as the time at which the upper limb of Comet 77P/Longmore touches the horizon, considering the effect of the atmospheric refraction. As the atmospheric conditions cannot be modeled precisely the times reported here should be considered correct with an approximation of few minutes.

Comet 77P/Longmore Orbital Elements

The following table lists the orbital elements of Comet 77P/Longmore at epoch 17 July 2010 00:00 UTC (JD: 2455395.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.35790750
Orbit inclination i 24.39924222°
Perihelion distance q 2.31109854 AU
345,735,422 km
Aphelion distance Q 4.88754823 AU
731,166,809 km
Semi-major axis a 3.59932338 AU
538,451,115 km
Orbital period period 6.8300 years
2,494.1911 days
Date of perihelion transit Tp 2009-Jul-07 23:20:04
2,455,020.4723 JD
Next perihelion transit 2016-May-06 03:55
2,457,514.6634 JD
Argument of perihelion peri 196.75230019549°
Longitude of the ascending node node 14.912855119912°
Mean anomaly M 54.129765195928°
Mean motion n 0.14433537°/day

Visualization of Comet 77P/Longmore Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet 77P/Longmore with respect of the Sun and the orbits of the major planets. The position of Comet 77P/Longmore and the planets along their orbits in this diagram accurately represents the current configuration of the objects in the Solar System. This is an experimental feature and it requires a WebGL enabled browser. Please provide us feedback!

Orbit Diagram of Comet 77P/Longmore
View Comet 77P/Longmore in the 3D Solar System Simulator

Comet 77P/Longmore 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. Click on each row of the table to locate Comet 77P/Longmore in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2021 Jan 18 02h 51m 10s +38° 47’ 08” 21.58 Perseus
2021 Jan 19 02h 51m 10s +38° 44’ 02” 21.58 Perseus
2021 Jan 20 02h 51m 11s +38° 40’ 59” 21.58 Perseus
2021 Jan 21 02h 51m 12s +38° 38’ 00” 21.59 Perseus
2021 Jan 22 02h 51m 16s +38° 35’ 04” 21.59 Perseus
2021 Jan 23 02h 51m 20s +38° 32’ 13” 21.60 Perseus
2021 Jan 24 02h 51m 26s +38° 29’ 26” 21.60 Perseus
2021 Jan 25 02h 51m 33s +38° 26’ 43” 21.60 Perseus
2021 Jan 26 02h 51m 42s +38° 24’ 03” 21.61 Perseus
2021 Jan 27 02h 51m 51s +38° 21’ 28” 21.61 Perseus
2021 Jan 28 02h 52m 01s +38° 18’ 56” 21.61 Perseus
2021 Jan 29 02h 52m 14s +38° 16’ 28” 21.62 Perseus
2021 Jan 30 02h 52m 27s +38° 14’ 05” 21.62 Perseus
2021 Jan 31 02h 52m 41s +38° 11’ 48” 21.63 Perseus