Comet 117P/Helin-Roman-Alu
Comet 117P/Helin-Roman-Alu is in the constellation of Taurus, at a distance of
Finder Charts
The sky charts below show, at different resolutions, the position of comet 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu from Earth is currently
The following graph shows the distance of comet 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu to Earth happened on Sunday 3 July 2022 at a distance of 2.030864 Astronomical Units, or 303,812,912 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 117P/Helin-Roman-Alu, 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 117P/Helin-Roman-Alu at epoch June, 11 2018 00:00 UTC (JD: 2458281.5). Source: JPL Small-Body Database
| Element | Symbol | Value |
|---|---|---|
| Orbit eccentricity | e | 0.25505040 |
| Orbit inclination | i | 8.70178786° |
| Perihelion distance | q | 3.04777985 AU 455,941,377 km |
| Aphelion distance | Q |
5.13473304 AU 768,145,131 km |
| Semi-major axis | a |
4.09125644 AU 612,043,254 km |
| Orbital period | period |
8.2755 years 3,022.6195 days |
| Date of perihelion transit | Tp | July 6, 2022 2,459,767.0441 JD |
| Next perihelion transit | October 15, 2030 2,462,789.6636 JD |
|
| Argument of perihelion | peri | 222.50173054801° |
| Longitude of the ascending node | node | 58.876826327174° |
| Mean anomaly | M | 183.06873505028° |
| Mean motion | n | 0.11910199°/day |
Orbit Visualization
The following chart is a 3D animated visualization of the orbit of comet 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu 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 22 2025 | 04h 47m 04s | +23° 43’ 58” | 19.74 | Taurus |
| Jun 23 2025 | 04h 48m 02s | +23° 46’ 18” | 19.74 | Taurus |
| Jun 24 2025 | 04h 49m 00s | +23° 48’ 37” | 19.74 | Taurus |
| Jun 25 2025 | 04h 49m 57s | +23° 50’ 55” | 19.74 | Taurus |
| Jun 26 2025 | 04h 50m 55s | +23° 53’ 11” | 19.74 | Taurus |
| Jun 27 2025 | 04h 51m 53s | +23° 55’ 26” | 19.74 | Taurus |
| Jun 28 2025 | 04h 52m 50s | +23° 57’ 39” | 19.74 | Taurus |
| Jun 29 2025 | 04h 53m 47s | +23° 59’ 51” | 19.74 | Taurus |
| Jun 30 2025 | 04h 54m 45s | +24° 02’ 02” | 19.74 | Taurus |
| Jul 01 2025 | 04h 55m 42s | +24° 04’ 12” | 19.74 | Taurus |
| Jul 02 2025 | 04h 56m 39s | +24° 06’ 20” | 19.73 | Taurus |
| Jul 03 2025 | 04h 57m 36s | +24° 08’ 27” | 19.73 | Taurus |
| Jul 04 2025 | 04h 58m 32s | +24° 10’ 33” | 19.73 | Taurus |
| Jul 05 2025 | 04h 59m 28s | +24° 12’ 37” | 19.73 | Taurus |
Additional Resources on TheSkyLive
- Comet 117P/Helin-Roman-Alu: Complete reference information on TheSkyLive.com.
- Where is comet 117P/Helin-Roman-Alu?: Key information on where to find comet 117P/Helin-Roman-Alu in the sky.
- Distance of comet 117P/Helin-Roman-Alu from Earth: Find out how far comet 117P/Helin-Roman-Alu is from Earth right now.
- How Bright is comet 117P/Helin-Roman-Alu?: Current visual brightness (magnitude) and apparent size.
- Rise and Set Times: Rise and set times of comet 117P/Helin-Roman-Alu from your location.
- Interactive Sky Map: Planetarium-style interactive visualization of comet 117P/Helin-Roman-Alu's position in the sky.
- Live Position Tracker: High precision real time tracker of comet 117P/Helin-Roman-Alu's position using deep space imagery.
- Ephemeris: 15 days comet 117P/Helin-Roman-Alu's computed ephemeris.
- Orbital elements: Information about comet 117P/Helin-Roman-Alu orbital parameters.
- Orbit Visualization: 3D interactive visualization showing the orbit of comet 117P/Helin-Roman-Alu with respect to the major Solar System objects.