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Comet 109P/Swift-Tuttle

Below the horizon.  Rise: 14:35 | Tran: 18:52 | Set: 23:09
Alt: -53.59°   Az: 33.98°   Direction: North-East

Comet 109P/Swift-Tuttle is in the constellation of Hydra, at a distance of 6,304,981,494.0 kilometers from Earth. The current Right Ascension is 09h 35m 37s and the Declination is -18° 51’ 11” (apparent coordinates). The predicted magnitude of Comet 109P/Swift-Tuttle is 37.01 (data provided by JPL Horizons).

Finder Charts

Map showing Comet 109P/Swift-Tuttle in Hydra on May, 17 2025. Field of view: 50x30 degrees
View interactive star map
Sky map showing Comet 109P/Swift-Tuttle in Hydra on May, 17 2025. Field of view: 15x9 degrees. View in interactive sky chart

High 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.

109P/Swift-Tuttle
RA: 09h 34m 26s
Dec: -18° 44’ 21”
Deep sky finder chart for Comet 109P/Swift-Tuttle. Field of view: 60x40 arcmins. View in deep sky object tracker

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.

Celestial Coordinates

Apparent

09h 35m 37s
-18° 51’ 11”
13h 22m 04s
22h 57m 42s

J2000

09h 34m 26s
-18° 44’ 21”

Additional Information

Hydra
n/a
n/a
n/a
n/a
37.01

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 109P/Swift-Tuttle from Greenwich, UK (all times relative to the local timezone Europe/London):

Azimuth: 108.8°
Max altitude: 19.7°
Azimuth: 251.2°
  • 109P/Swift-Tuttle is below the horizon from Greenwich, UK.
  • 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.

Distance from Earth

The distance of Comet 109P/Swift-Tuttle from Earth is currently 6,304,981,494.0 kilometers, equivalent to 42.1461981009 Astronomical Units. Light takes 5h 50m 31.154s to travel from Comet 109P/Swift-Tuttle and arrive to us.

6,304,981,494.0
42.1461981009
5h 50m 31.154s

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

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
4,901,610,600
32.765243

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 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

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
2h1>Orbit Visualization
Orbit Diagram of Comet 109P/Swift-Tuttle
View Comet 109P/Swift-Tuttle in the 3D Solar System Simulator

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. Apparent celestial coordinates are provided.

Date Right AscensionR.A. DeclinationDec. MagnitudeMag Constellation
2025 May 10 09h 35m 36s -18° 57’ 02” 37.01 Hydra
2025 May 11 09h 35m 36s -18° 56’ 13” 37.01 Hydra
2025 May 12 09h 35m 36s -18° 55’ 24” 37.01 Hydra
2025 May 13 09h 35m 36s -18° 54’ 36” 37.01 Hydra
2025 May 14 09h 35m 36s -18° 53’ 47” 37.01 Hydra
2025 May 15 09h 35m 36s -18° 53’ 00” 37.01 Hydra
2025 May 16 09h 35m 36s -18° 52’ 13” 37.01 Hydra
2025 May 17 09h 35m 37s -18° 51’ 26” 37.01 Hydra
2025 May 18 09h 35m 37s -18° 50’ 39” 37.01 Hydra
2025 May 19 09h 35m 38s -18° 49’ 54” 37.02 Hydra
2025 May 20 09h 35m 38s -18° 49’ 08” 37.02 Hydra
2025 May 21 09h 35m 39s -18° 48’ 24” 37.02 Hydra
2025 May 22 09h 35m 40s -18° 47’ 39” 37.02 Hydra
2025 May 23 09h 35m 41s -18° 46’ 56” 37.02 Hydra

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