Comet 109P/Swift-Tuttle
Comet 109P/Swift-Tuttle is in the constellation of
Hydra,
at a distance of
Finder Charts
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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.


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
J2000
Additional Information
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):
- 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
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Distance from Earth
The distance of Comet 109P/Swift-Tuttle from Earth is currently
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.
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:
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.
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 |
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 |
Additional Resources on TheSkyLive
- Comet 109P/Swift-Tuttle: Complete reference information on TheSkyLive.com
- Where is Comet 109P/Swift-Tuttle?: Key information on locating Comet 109P/Swift-Tuttle in the sky.
- Distance from Earth: Find out how far Comet 109P/Swift-Tuttle is from Earth right now.
- How Bright is Comet 109P/Swift-Tuttle?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Comet 109P/Swift-Tuttle's rise and set times from your location.
- Interactive Sky Map: planetarium-style interactive visualization of Comet 109P/Swift-Tuttle's position in the sky.
- Live Position Tracker: high precision position tracker with deep space imagery.
- Ephemeris: 15 days Comet 109P/Swift-Tuttle's computed ephemeris.
- Orbital elements: information about Comet 109P/Swift-Tuttle orbital parameters.
- Orbit Visualization. 3d interactive visualization showing the orbit of Comet 109P/Swift-Tuttle with respect to the major Solar System objects.