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Comet 117P/Helin-Roman-Alu

Above the horizon.  Rise: 9:36 | Tran: 17:05 | Set: 0:37
Alt: 19.98°   Az: 272.71°   Direction: West

Comet 117P/Helin-Roman-Alu is in the constellation of Aries, at a distance of 721,633,799.0 kilometers from Earth. The current Right Ascension is 03h 00m 49s and the Declination is +17° 09’ 08” (apparent coordinates). The predicted magnitude of Comet 117P/Helin-Roman-Alu is 19.10 (data provided by JPL Horizons).

Finder Charts

Map showing Comet 117P/Helin-Roman-Alu in Aries on February, 18 2025. Field of view: 50x30 degrees
View interactive star map
Sky map showing Comet 117P/Helin-Roman-Alu in Aries on February, 18 2025. Field of view: 15x9 degrees. View in interactive sky chart

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.

117P/Helin-Roman-Alu
RA: 02h 59m 24s
Dec: +17° 03’ 12”
Deep sky finder chart for Comet 117P/Helin-Roman-Alu. Field of view: 60x40 arcmins. View in deep sky object tracker

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

03h 00m 49s
+17° 09’ 08”
05h 17m 02s
08h 17m 51s

J2000

02h 59m 24s
+17° 03’ 12”

Additional Information

Aries
n/a
n/a
n/a
n/a
19.10

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):

Azimuth: 72.9°
Max altitude: 55.7°
Azimuth: 287.1°
  • 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 721,633,799.0 kilometers, equivalent to 4.8238239998 Astronomical Units. Light takes 40m 7.111s to travel from Comet 117P/Helin-Roman-Alu and arrive to us.

721,633,799.0
4.8238239998
40m 7.111s

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.

Chart of the distance of Comet 117P/Helin-Roman-Alu 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 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:

Sun Jul 3 2022
303,812,912
2.030864

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.

Chart of the magnitude of Comet 117P/Helin-Roman-Alu as a function of time

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

Orbit Diagram of Comet 117P/Helin-Roman-Alu
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