Comet 117P/Helin-Roman-Alu
Comet 117P/Helin-Roman-Alu is in the constellation of
Aries,
at a distance of
Finder Charts
View interactive star map
High precision deep sky finder chart, 60 arcmin wide, showing where Comet 117P/Helin-Roman-Alu is right now. Click on the image to see a more detailed fullscreen tracker view.


Also check out Where is Comet 117P/Helin-Roman-Alu?, a page that provides all the information needed to find Comet 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu from Greenwich, UK (all times relative to the local timezone Europe/London):
- 117P/Helin-Roman-Alu is above the horizon from Greenwich, UK.
- Right now it is placed in the West direction at an altitude of 19.98° above the horizon.
- Given its current magnitude, 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu from Earth is currently
The following chart shows the distance of Comet 117P/Helin-Roman-Alu 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 117P/Helin-Roman-Alu from Earth is also available as a real time updated value in the Live Position and Data Tracker.
Closest Approach
Between 1 January 2000 and 31 December 2099, the closest approach of Comet 117P/Helin-Roman-Alu to Earth happens on Sun Jul 3 2022 at a distance of 2.030864 Astronomical Units, or 303,812,912 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 117P/Helin-Roman-Alu, 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 117P/Helin-Roman-Alu at epoch 11 June 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 | 2022-Jul-06 13:03:34 2,459,767.0441 JD |
Next perihelion transit | 2030-Oct-15 03:55 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
View Comet 117P/Helin-Roman-Alu in the 3D Solar System Simulator
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 |
---|---|---|---|---|
2025 Feb 11 | 02h 57m 09s | +16° 47’ 10” | 19.02 | Aries |
2025 Feb 12 | 02h 57m 34s | +16° 49’ 48” | 19.03 | Aries |
2025 Feb 13 | 02h 58m 00s | +16° 52’ 30” | 19.04 | Aries |
2025 Feb 14 | 02h 58m 27s | +16° 55’ 13” | 19.05 | Aries |
2025 Feb 15 | 02h 58m 54s | +16° 57’ 58” | 19.06 | Aries |
2025 Feb 16 | 02h 59m 22s | +17° 00’ 45” | 19.07 | Aries |
2025 Feb 17 | 02h 59m 51s | +17° 03’ 35” | 19.08 | Aries |
2025 Feb 18 | 03h 00m 20s | +17° 06’ 27” | 19.09 | Aries |
2025 Feb 19 | 03h 00m 51s | +17° 09’ 20” | 19.10 | Aries |
2025 Feb 20 | 03h 01m 21s | +17° 12’ 16” | 19.11 | Aries |
2025 Feb 21 | 03h 01m 53s | +17° 15’ 14” | 19.12 | Aries |
2025 Feb 22 | 03h 02m 24s | +17° 18’ 14” | 19.13 | Aries |
2025 Feb 23 | 03h 02m 57s | +17° 21’ 15” | 19.14 | Aries |
2025 Feb 24 | 03h 03m 30s | +17° 24’ 18” | 19.15 | Aries |
Additional Resources
- Position and finder charts (see also Where is Comet 117P/Helin-Roman-Alu?)
- Distance from Earth (see also How far is Comet 117P/Helin-Roman-Alu from Earth?)
- When does Comet 117P/Helin-Roman-Alu rise and set?
- Brightness (see also How bright is Comet 117P/Helin-Roman-Alu?)
- Orbital elements. Detailed information about Comet 117P/Helin-Roman-Alu orbital parameters.
- Interactive orbit visualization. 3d visualization showing the orbit of Comet 117P/Helin-Roman-Alu with respect to the major Solar System objects.
- 15 days ephemerides. Table showing celestial coordinates and magnitude of Comet 117P/Helin-Roman-Alu for the past and next 7 days.
- Interactive sky chart. An online planetarium application that shows where to locate Comet 117P/Helin-Roman-Alu in the sky from your location.
- Live position tracker. A high precision sky chart that uses real deep sky imagery to help locate Comet 117P/Helin-Roman-Alu with your telescope or on your astrophotographies.