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Comet 109P/Swift-Tuttle

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Comet 109P/Swift-Tuttle Position

Comet 109P/Swift-Tuttle is currently in the constellation of Hydra. The current Right Ascension is 09h 35m 31s and the Declination is -20° 49’ 22”.

09h 35m 31s
-20° 49’ 22”

Simplified sky chart showing where Comet 109P/Swift-Tuttle is right now in the sky with respect to the brightest stars and constellations (see full screen Online Planetarium)

Map showing Comet 109P/Swift-Tuttle in Hydra on April, 08 2020
Field of view: 60x30 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 showing where Comet 109P/Swift-Tuttle is right now (view fullscreen)

RA: 09h 35m 31s
Dec: -20° 49’ 22”
Deep sky finder chart for Comet 109P/Swift-Tuttle
Field of view: 60x40 arcmins
View fullscreen

Also check out Where is Comet 109P/Swift-Tuttle?, a page that provides all the information needed to find Comet 109P/Swift-Tuttle in the sky and additional links to sky charts.

Comet 109P/Swift-Tuttle Distance

The distance of Comet 109P/Swift-Tuttle from Earth is currently 5,758,124,302 kilometers, equivalent to 38.490684 Astronomical Units. Light takes 5 hours, 20 minutes and 7.0352 seconds to travel from Comet 109P/Swift-Tuttle and arrive to us.

5 hours, 20 minutes and 7.0352 seconds

The following chart shows the distance of Comet 109P/Swift-Tuttle 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 109P/Swift-Tuttle 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 109P/Swift-Tuttle from Earth is also available as a real time updated value in the Live Position and Data Tracker.

Closest approach of Comet 109P/Swift-Tuttle to Earth

Between January 2013 and December 2100 the closest approach of Comet 109P/Swift-Tuttle to Earth happens on Sun Feb 17 2013 at a distance of 32.76524303 Astronomical Units, or 4,901,610,600 kilometers:

Sun Feb 17 2013

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

Comet 109P/Swift-Tuttle brightness

The current visual magnitude of Comet 109P/Swift-Tuttle is 36.31.


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 109P/Swift-Tuttle, 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 109P/Swift-Tuttle between January 2013 and December 2100

Comet 109P/Swift-Tuttle 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 109P/Swift-Tuttle rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 110.8°
Max altitude: 17.7°
Azimuth: 249.2°
Comet 109P/Swift-Tuttle is above the horizon from Greenwich, United Kingdom

The rise and set times are defined as the time at which the upper limb of Comet 109P/Swift-Tuttle 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 109P/Swift-Tuttle Orbital Elements

The following table lists the orbital elements of Comet 109P/Swift-Tuttle at epoch 09 October 1995 00:00 UTC (JD: 2450000.5). Source: JPL Small-Body Database

Element Symbol Value
Orbit eccentricity e 0.96322576
Orbit inclination i 113.45381700°
Perihelion distance q 0.95951616 AU
143,541,574 km
Aphelion distance Q 51.22462284 AU
7,663,094,520 km
Semi-major axis a 26.09206950 AU
3,903,318,047 km
Orbital period period 133.2800 years
48,681.1935 days
Date of perihelion transit Tp 1992-Dec-11 23:59:41
2,448,968.4998 JD
Next perihelion transit 2126-Mar-26 04:38
2,497,649.6932 JD
Argument of perihelion peri 152.98216763059°
Longitude of the ascending node node 139.38119208159°
Mean anomaly M 7.6316961671242°
Mean motion n 0.00739505°/day

Visualization of Comet 109P/Swift-Tuttle Orbit

This 3d orbit diagram is a feature of our 3D Solar System Simulator and shows the orbit of Comet 109P/Swift-Tuttle with respect of the Sun and the orbits of the major planets. The position of Comet 109P/Swift-Tuttle 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 109P/Swift-Tuttle
View Comet 109P/Swift-Tuttle in the 3D Solar System Simulator

Comet 109P/Swift-Tuttle 15 Days Ephemeris

The following table lists the ephemerides of Comet 109P/Swift-Tuttle computed for the past and next 7 days, with a 24 hours interval. Click on each row of the table to locate Comet 109P/Swift-Tuttle in our Online Planetarium at the chosen date.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2020 Apr 01 09h 36m 01s -20° 57’ 20” 36.30 Hydra
2020 Apr 02 09h 35m 57s -20° 56’ 20” 36.30 Hydra
2020 Apr 03 09h 35m 53s -20° 55’ 19” 36.30 Hydra
2020 Apr 04 09h 35m 48s -20° 54’ 20” 36.30 Hydra
2020 Apr 05 09h 35m 45s -20° 53’ 20” 36.30 Hydra
2020 Apr 06 09h 35m 42s -20° 52’ 19” 36.31 Hydra
2020 Apr 07 09h 35m 38s -20° 51’ 19” 36.31 Hydra
2020 Apr 08 09h 35m 35s -20° 50’ 18” 36.31 Hydra
2020 Apr 09 09h 35m 30s -20° 49’ 18” 36.31 Hydra
2020 Apr 10 09h 35m 27s -20° 48’ 16” 36.31 Hydra
2020 Apr 11 09h 35m 25s -20° 47’ 16” 36.31 Hydra
2020 Apr 12 09h 35m 21s -20° 46’ 14” 36.31 Hydra
2020 Apr 13 09h 35m 17s -20° 45’ 14” 36.31 Hydra
2020 Apr 14 09h 35m 15s -20° 44’ 12” 36.31 Hydra