Comet 38P/Stephan-Oterma
Comet 38P/Stephan-Oterma is in the constellation of Libra, at a distance of
Finder Charts
The sky charts below show, at different resolutions, the position of comet 38P/Stephan-Oterma in the sky. Click on each chart to access the interactive star map tool.
The following map uses photographic imagery from the Digitized Sky Survey (DSS) to realistically visualize the precise position of comet 38P/Stephan-Oterma against the stars in the background. The horizontal size of the map measures 60 arcminutes. Click on the image to access a more detailed full-screen view.
Equatorial 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
The following table lists today's rise, transit and set times of comet 38P/Stephan-Oterma from Greenwich, UK (all times relative to the local timezone Europe/London):
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 38P/Stephan-Oterma from Earth is currently
The following graph shows the distance of comet 38P/Stephan-Oterma from Earth as a function of time. In the chart the distance is measured in Astronomical Units and the data is sampled with an interval of 1 day.
Note: The values in this chart may not be entirely accurate around the time of closest approach for objects passing very close to Earth at high speed (e.g., Near-Earth Objects).
The value of the distance of 38P/Stephan-Oterma from Earth is also available as a real time updated value in the live position tracker.
Closest Approach to Earth
In the period between January 1, 2000 and December 31, 2099, the closest approach of comet 38P/Stephan-Oterma to Earth happened on Monday 17 December 2018 at a distance of 0.765727 Astronomical Units, or 114,551,108 kilometers:
Note: the values for the closest approach are computed with a sampling interval of 1 day.
Light Curve
The following chart shows the light curve of comet 38P/Stephan-Oterma, i.e., its apparent magnitude as a function of time. The curve is calculated using the latest ephemerides provided by JPL Horizons. The magnitude data is sampled with the interval of 2 days. Because of this sampling, inaccuracies may occur for objects that have large variations of brightness over a few days. For comets, large discrepancies can arise between the calculated brightness and the observations due to their highly dynamic, and not always precisely predictable, behavior.
Orbital Elements
The following table lists the orbital elements of comet 38P/Stephan-Oterma at epoch May, 27 2018 00:00 UTC (JD: 2458266.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.85928734 |
| Orbit inclination | i | 18.35295008° |
| Perihelion distance | q | 1.58850911 AU 237,637,581 km |
| Aphelion distance | Q |
20.98954679 AU 3,139,991,513 km |
| Semi-major axis | a |
11.28902795 AU 1,688,814,547 km |
| Orbital period | period |
37.9309 years 13,854.2573 days |
| Date of perihelion transit | Tp | November 10, 2018 2,458,433.4871 JD |
| Next perihelion transit | October 16, 2056 2,472,287.7444 JD |
|
| Argument of perihelion | peri | 359.58851167059° |
| Longitude of the ascending node | node | 78.000299016178° |
| Mean anomaly | M | 355.66087469768° |
| Mean motion | n | 0.02598479°/day |
Orbit Visualization
The following chart is a 3D animated visualization of the orbit of comet 38P/Stephan-Oterma relative to the other major objects in the Solar System. You can access more advanced features using our 3D Solar System Viewer.
15 Days Ephemeris
The following table lists the ephemerides of comet 38P/Stephan-Oterma 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 |
|---|---|---|---|---|
| Jun 29 2025 | 15h 34m 13s | -11° 43’ 47” | 28.32 | Libra |
| Jun 30 2025 | 15h 34m 02s | -11° 43’ 41” | 28.33 | Libra |
| Jul 01 2025 | 15h 33m 52s | -11° 43’ 37” | 28.33 | Libra |
| Jul 02 2025 | 15h 33m 42s | -11° 43’ 33” | 28.33 | Libra |
| Jul 03 2025 | 15h 33m 32s | -11° 43’ 30” | 28.34 | Libra |
| Jul 04 2025 | 15h 33m 22s | -11° 43’ 30” | 28.34 | Libra |
| Jul 05 2025 | 15h 33m 13s | -11° 43’ 29” | 28.34 | Libra |
| Jul 06 2025 | 15h 33m 04s | -11° 43’ 30” | 28.35 | Libra |
| Jul 07 2025 | 15h 32m 55s | -11° 43’ 32” | 28.35 | Libra |
| Jul 08 2025 | 15h 32m 46s | -11° 43’ 36” | 28.35 | Libra |
| Jul 09 2025 | 15h 32m 38s | -11° 43’ 39” | 28.36 | Libra |
| Jul 10 2025 | 15h 32m 30s | -11° 43’ 45” | 28.36 | Libra |
| Jul 11 2025 | 15h 32m 22s | -11° 43’ 51” | 28.36 | Libra |
| Jul 12 2025 | 15h 32m 14s | -11° 43’ 59” | 28.37 | Libra |
Additional Resources on TheSkyLive
- Comet 38P/Stephan-Oterma: Complete reference information on TheSkyLive.com.
- Where is comet 38P/Stephan-Oterma?: Key information on where to find comet 38P/Stephan-Oterma in the sky.
- Distance of comet 38P/Stephan-Oterma from Earth: Find out how far comet 38P/Stephan-Oterma is from Earth right now.
- How Bright is comet 38P/Stephan-Oterma?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Rise and set times of comet 38P/Stephan-Oterma from your location.
- Interactive Sky Map: Planetarium-style interactive visualization of comet 38P/Stephan-Oterma's position in the sky.
- Live Position Tracker: High precision real time tracker of comet 38P/Stephan-Oterma's position using deep space imagery.
- Ephemeris: 15 days comet 38P/Stephan-Oterma's computed ephemeris.
- Orbital elements: Information about comet 38P/Stephan-Oterma orbital parameters.
- Orbit Visualization: 3D interactive visualization showing the orbit of comet 38P/Stephan-Oterma with respect to the major Solar System objects.