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🌎  Observing from: Greenwich, United Kingdom [change]
🌅 Sunrise: 6:45  ☀️ Transit: 13:03  🌅 Sunset: 19:23

Comet 109P/Swift-Tuttle

Comet 109P/Swift-Tuttle is currently in the constellation of Hydra. The current Right Ascension of Comet 109P/Swift-Tuttle is 09h 36m 07s and the Declination is -20° 04’ 03” (topocentric coordinates computed for the selected location: Greenwich, United Kingdom [change]). The current estimated magnitude of Comet 109P/Swift-Tuttle is 36.72 (JPL).

09h 36m 07s
-20° 04’ 03”

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

Azimuth: 110.1°
Max altitude: 18.5°
Azimuth: 249.9°
  • 109P/Swift-Tuttle is below the horizon from Greenwich, United Kingdom [change].
  • Given its current magnitude, 109P/Swift-Tuttle is visible only through long exposure photography.
  • 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.

Available Resources

Comet 109P/Swift-Tuttle Position and Finder Charts

Below we provide Comet 109P/Swift-Tuttle 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 109P/Swift-Tuttle in Hydra on March, 28 2023
Field of view: 50x30 degrees
View fullscreen
Map showing Comet 109P/Swift-Tuttle in Hydra on March, 28 2023
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 109P/Swift-Tuttle is right now. Click on the image to see a more detailed fullscreen tracker view.

RA: 09h 36m 07s
Dec: -20° 04’ 03”
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 from Earth

The distance of Comet 109P/Swift-Tuttle from Earth is currently 6,027,306,320 kilometers, equivalent to 40.290054 Astronomical Units. Light takes 5 hours, 35 minutes and 4.9298 seconds to travel from Comet 109P/Swift-Tuttle and arrive to us.

5 hours, 35 minutes and 4.9298 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.

Chart of the distance of Comet 109P/Swift-Tuttle from Earth in Astronomical Units (au)

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 1 January 2013 and 30 December 2100, the closest approach of Comet 109P/Swift-Tuttle to Earth happens on Sun Feb 17 2013 at a distance of 32.765243 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 36.72.


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.

Chart of the magnitude of Comet 109P/Swift-Tuttle as a function of time

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 133.2818 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
2023 Mar 21 09h 36m 42s -20° 10’ 45” 36.71 Hydra
2023 Mar 22 09h 36m 37s -20° 09’ 52” 36.71 Hydra
2023 Mar 23 09h 36m 33s -20° 08’ 59” 36.71 Hydra
2023 Mar 24 09h 36m 28s -20° 08’ 07” 36.72 Hydra
2023 Mar 25 09h 36m 24s -20° 07’ 14” 36.72 Hydra
2023 Mar 26 09h 36m 19s -20° 06’ 20” 36.72 Hydra
2023 Mar 27 09h 36m 15s -20° 05’ 26” 36.72 Hydra
2023 Mar 28 09h 36m 10s -20° 04’ 32” 36.72 Hydra
2023 Mar 29 09h 36m 06s -20° 03’ 37” 36.72 Hydra
2023 Mar 30 09h 36m 02s -20° 02’ 42” 36.72 Hydra
2023 Mar 31 09h 35m 57s -20° 01’ 46” 36.72 Hydra
2023 Apr 01 09h 35m 53s -20° 00’ 51” 36.72 Hydra
2023 Apr 02 09h 35m 49s -19° 59’ 56” 36.72 Hydra
2023 Apr 03 09h 35m 45s -19° 58’ 59” 36.72 Hydra